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Ailmemts & Remedies

Anaphylax

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ALTERNATIVE NAMES:  Anaphylactic reaction; Anaphylactic shock; Shock – anaphylactic

DEFINITION:
Anaphylaxis is an acute multi-system severe type I hypersensitivity reaction. The term comes from the Greek words ava ana (against) and  phylaxis (protection).It is  a life-threatening type of allergic reaction and it can occur within seconds or minutes of exposure to something you’re allergic to, such as the venom from a bee sting or a peanut.

The flood of chemicals released by your immune system during anaphylaxis can cause you to go into shock; your blood pressure drops suddenly and your airways narrow, blocking normal breathing. Signs and symptoms of anaphylaxis include a rapid, weak pulse, a skin rash, and nausea and vomiting. Common triggers of anaphylaxis include certain foods, some medications, insect venom and latex.

.CLICK & SEE

Due in part to the variety of definitions, between 1% and 15% of the population of the United States can be considered “at risk” for having an anaphylactic reaction if they are exposed to one or more allergens. Of those people who actually experience anaphylaxis, up to 1% may die as a result. Anaphylaxis results in approximately 1,500 deaths per year in the U.S. In England, mortality rates for anaphylaxis have been reported as up to 0.05 per 100,000 population, or around 10-20 a year. Anaphylactic reactions requiring hospital treatment appear to be increasing, with authorities in England reporting a threefold increase between 1994 and 2004.

Based on the pathophysiology, anaphylaxis can be divided into “true anaphylaxis” and “pseudo-anaphylaxis” or “anaphylactoid reaction.” The symptoms, treatment, and risk of death are the same; however, “true” anaphylaxis is caused by degranulation of mast cells or basophils mediated by immunoglobulin E (IgE), and pseudo-anaphylaxis occurs without IgE mediation.

Classification:
Biphasic anaphylaxis:..CLICK & SEE
Biphasic anaphylaxis is the recurrence of symptoms within 72 hours with no further exposure to the allergen. It occurs in between 1–20% of cases depending on the study examined. It is managed in the same manner as anaphylaxis.

Anaphylactic shock:...CLICK & SEE
Anaphylactic shock is anaphylaxis associated with systemic vasodilation which results in low blood pressure. It is also associated with severe bronchoconstriction to the point where the individual is unable to breathe.

Pseudoanaphylaxis:….CLICK & SEE
The presentation and treatment of pseudoanaphylaxis is similar to that of anaphylaxis. It however does not involve an allergic reaction but is due to direct mast cell degranulation. This can result from morphine, radiocontrast, aspirin and muscle relaxants.[11]

Active anaphylaxis:….CLICK & SEE
Active anaphylaxis is what is naturally observed. Two weeks or so after an animal, including humans, is exposed to certain allergens, active anaphylaxis (which is simply called “anaphylaxis”) would be elicited upon exposure to the same allergens.

Passive anaphylaxis:....CLICK & SEE
Passive anaphylaxis is induced in native animals which receive transfer of the serum experimentally from sensitized animals with certain allergens. Passive anaphylaxis would be provoked in the recipient animals after exposure to the same allergens.

SIGNS & SYMPTOMS :
Anaphylaxis can present with many different symptoms due to the systemic effects of histamine release. These usually develop over minutes to hours.[9] The most common areas affected include: skin (80% to 90%), respiratory (70%), gastrointestinal (30% to 45%), heart and vasculature (10% to 45%), and central nervous system (10% to 15%).

Skin:
Skin involvement may include generalized hives, itchiness, flushing, and swelling of the lips, tongue or throat….

Respiratory:
Respiratory symptoms may include shortness of breath, wheezes or stridor, and low oxygen.

Gastrointestinal:

Gastrointestinal symptoms may include crampy abdominal pain, diarrhea, and vomiting.

Cardiovascular:
Due to the presence of histamine releasing cells in the heart, coronary artery spasm may occur with subsequent myocardial infarction or dysrhythmia.

Nervous sys:

temA drop in blood pressure may result in a feeling of lightheadedness and loss of consciousness. There may be a loss of bladder control and muscle tone, and a feeling of anxiety and “impending doom”.

CAUSES:
Anaphylaxis can occur in response to any allergen. Common triggers include insect bites or stings, foods, medication and latex rubber

Tissues in different parts of the body release histamine and other substances. This causes the airways to tighten and leads to other symptoms.

Some drugs (morphine, x-ray dye, and others) may cause an anaphylactic-like reaction (anaphylactoid reaction) when people are first exposed to them. Aspirin may also cause a reaction. These reactions are not the same as the immune system response that occurs with “true” anaphylaxis. However, the symptoms, risk for complications, and treatment are the same for both types of reactions.

Anaphylaxis can occur in response to any allergen. Common causes include:

•Drug allergies :Any medication may potentially trigger anaphylaxis. The most common to do so include antibiotics (?-lactam antibiotics in particular), aspirin, ibuprofen, and other analgesics. Some drugs (polymyxin, morphine, x-ray contrast and others) may cause an “anaphylactoid” reaction (anaphylactic-like reaction) on the first exposure. This is usually due to a toxic reaction, rather than the immune system mechanism that occurs with “true” anaphylaxis. The symptoms, risk for complications without treatment, and treatment are the same, however, for both types of reactions. Some vaccinations are also known to cause “anaphylactoid” reactions....CLICK & SEE

•Food allergies :The most common are peanut, tree nuts, shellfish, fish, milk, and egg. Severe cases are usually the result of ingesting the allergen…...CLICK & SEE

•Insect bites/stings : Venom from stinging or biting insects such as Hymenoptera or Hemiptera may induce anaphylaxis in susceptible people…..CLICK & SEE

Pollens and other inhaled allergens rarely cause anaphylaxis. Some people have an anaphylactic reaction with no known cause…..CLICK & SEE

Less common causes of anaphylaxis include:

*Latex
*Muscle relaxants used during general anesthesia
*Exercise

Anaphylaxis triggered by exercise varies from person to person. In some people, aerobic activity, such as jogging, triggers anaphylaxis. In others, less intense physical activity, such as walking, can trigger a reaction. Eating certain foods before exercise or exercising when the weather is hot, cold or humid has also been linked to anaphylaxis in some people. Talk with your doctor about any precautions you should take when exercising.

Anaphylaxis symptoms are sometimes caused by aspirin, other nonsteroidal anti-inflammatory drugs — such as ibuprofen (Advil, Motrin, others) and naproxen sodium (Aleve, Midol Extended Relief) — and the intravenous (IV) contrast used in some X-ray imaging tests. Although similar to allergy-induced anaphylaxis, this type of reaction isn’t triggered by allergy antibodies.

If you don’t know what triggers your allergy attack, your doctor may do tests to try to identify the offending allergen. In some cases, the cause of anaphylaxis is never identified. This is known as idiopathic anaphylaxis.

Anaphylaxis is life-threatening and can occur at any time. Risks include a history of any type of allergic reaction.

DIAGNOSIS:
Anaphylaxis is diagnosed with high likelihood based on clinical criteria. These criteria are fulfilled when any one of the following three is true:[14]

1.Symptom onset within minutes to several hours of allergen exposure with involvement of the skin or mucosal tissue and any of the following: hives, itchiness, or swelling of the airway; plus either respiratory difficulty or a low blood pressure.

2.Any two or more of the following symptoms within minutes to several hours of allergen exposure: a. Involvement of the skin or mucosa b. Respiratory difficulties c. Low blood pressure d. Gastrointestinal symptoms

3.Low blood pressure within minutes to several hours after exposure to known allergen

Apart from its clinical features, blood tests for tryptase (released from mast cells) might be useful in diagnosing anaphylaxis.

Allergy testing may help in determining what triggered the anaphylaxis. In this setting, skin allergy testing (with or without patch testing) or RAST blood tests can sometimes identify the cause.

TREATMENT :
Anaphylaxis is an emergency condition requiring immediate professional medical attention. Call 911 immediately.

Check the person’s airway, breathing, and circulation (the ABC’s of Basic Life Support). A warning sign of dangerous throat swelling is a very hoarse or whispered voice, or coarse sounds when the person is breathing in air. If necessary, begin rescue breathing and CPR.

1.Call 911.
2.Calm and reassure the person.
3.If the allergic reaction is from a bee sting, scrape the stinger off the skin with something firm (such as a fingernail or plastic credit card). Do not use tweezers — squeezing the stinger will release more venom.
4.If the person has emergency allergy medication on hand, help the person take or inject the medication. Avoid oral medication if the person is having difficulty breathing.
5.Take steps to prevent shock. Have the person lie flat, raise the person’s feet about 12 inches, and cover him or her with a coat or blanket. Do NOT place the person in this position if a head, neck, back, or leg injury is suspected, or if it causes discomfort.

PROVIDING FIRST AID:
Although emergency medical help is essential, there are things that must be done to improve survival chances. If the person affected is conscious and having breathing difficulties, help them sit up. If they’re shocked with low blood pressure, they’re better off lying flat with their legs raised.

If the person is unconscious, check their airways and breathing, and put them in the recovery position.

If you know that the person is susceptible to anaphylaxis, ask if they carry a preloaded adrenaline syringe. If necessary, help the person inject it into their thigh muscle.  If available, antihistamines and steroids should also be given.

DO NOT:
•Do NOT assume that any allergy shots the person has already received will provide complete protection.
•Do NOT place a pillow under the person’s head if he or she is having trouble breathing. This can block the airways.
•Do NOT give the person anything by mouth if the person is having trouble breathing.
Paramedics or physicians may place a tube through the nose or mouth into the airways (endotracheal intubation) or perform emergency surgery to place a tube directly into the trachea (tracheostomy or cricothyrotomy).

The person may receive antihistamines, such as diphenhydramine, and corticosteroids, such as prednisone, to further reduce symptoms (after lifesaving measures and epinephrine are given).

You may click to see :

Natural Allergy Relief For Oak Pollen

Anaphylactic reactions in children – a questionnaire-based survey in Germany

PROGNOSIS:
Anaphylaxis is a severe disorder that can be life-threatening without prompt treatment. However, symptoms usually get better with the right therapy, so it is important to act right away.

Possible Complications:
•Airway blockage
•Cardiac arrest (no effective heartbeat)
•Respiratory arrest (no breathing)
•Shock

RISK FACTORS:

There aren’t many known risk factors for anaphylaxis, but some things that may increase your risk include:

*A personal history of anaphylaxis. If you’ve experienced anaphylaxis once, your risk of having this serious reaction is increased. Future reactions may be more severe than the first reaction.

*Allergies or asthma. People who have either condition are at increased risk of having anaphylaxis.

*A family history.
If you have family members who have experienced exercised-induced anaphylaxis, your risk of developing this type of anaphylaxis is higher than it is for someone without a family history.

PREVENTION:
Immunotherapy with Hymenoptera venoms is effective against allergies to bees, wasps, hornets, yellow jackets, white faced hornets, and fire ants.

The greatest success with prevention of anaphylaxis has been the use of allergy injections to prevent recurrence of sting allergy. The risk to an individual from a particular species of insect depends on complex interactions between likelihood of human contact, insect aggression, efficiency of the venom delivery apparatus, and venom allergenicity. Venom immunotherapy reduces risk of systemic reactions below 3%.[citation needed] One simple method of venom extraction has been electrical stimulation to obtain venom, instead of dissecting the venom sac.

A potential vaccine has been developed to prevent anaphylaxis due to peanut and tree nut allergies if they are exposed to a small amount of peanuts or nuts. Although it shows some promise to reduce the likelihood of anaphylaxis in affected individuals, the vaccine has not yet been approved for marketing and distribution. Desensitization techniques are also being studied for peanut allergies.

•Avoid triggers such as foods and medications that have caused an allergic reaction (even a mild one) in the past. Ask detailed questions about ingredients when you are eating away from home. Also carefully examine ingredient labels.

•If you have a child who is allergic to certain foods, introduce one new food at a time in small amounts so you can recognize an allergic reaction.

•People who know that they have had serious allergic reactions should wear a medical ID tag.

•If you have a history of serious allergic reactions, carry emergency medications (such as a chewable form of diphenhydramine and injectable epinephrine or a bee sting kit) according to your health care provider’s instructions.

•Do not use your injectable epinephrine on anyone else. They may have a condition (such as a heart problem) that could be negatively affected by this drug.

Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.

Resources:
http://www.nlm.nih.gov/medlineplus/ency/article/000844.htm
http://www.mayoclinic.com/health/anaphylaxis/DS00009
http://www.bbc.co.uk/health/physical_health/conditions/in_depth/allergies/allergicconditions_anaphylaxis.shtml
http://en.wikipedia.org/wiki/Anaphylaxis
http://www.bailey-law.com/files/anaphylaxis.html
http://www.absoluteastronomy.com/topics/Anaphylaxis

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Ailmemts & Remedies

Allergic Asthma

Definition:
Allergic (extrinsic) asthma is characterized by symptoms that are triggered by an allergic reaction. Allergic asthma is airway obstruction and inflammation that is partially reversible with medication. Allergic asthma is the most common form of asthma, affecting over 50% of the 20 million asthma sufferers.Over 2.5 million children under age 18 suffer from allergic asthma. Many of the symptoms of allergic and non-allergic asthma are the same (coughing, wheezing, shortness of breath or rapid breathing, and chest tightness). However, allergic asthma is triggered by inhaled allergens such as dust mite allergen, pet dander, pollen, mold, etc. resulting in asthma symptoms.

click & see the pictures
Allergies and asthma often occur together. The same substances that trigger your hay fever symptoms may also cause asthma signs and symptoms such as shortness of breath, wheezing and chest tightness. This is called allergic asthma or allergy-induced asthma. Substances such as pollen, dust mites and pet dander are common triggers. In some people, skin or food allergies can cause asthma symptoms.

An allergic response occurs when immune system chemicals (antibodies) mistakenly identify a harmless substance such as tree pollen as a dangerous invader. In an attempt to protect your body from the substance, antibodies attack the allergen. The chemicals released by your immune system lead to allergy signs and symptoms, such as nasal congestion, runny nose, itchy eyes or skin reactions. For some people, this same reaction also affects the lungs and airways, leading to asthma symptoms.

Symptoms:

The main symptoms are coughing, wheezing, shortness of breath and a tight feeling in the chest.

…...CLICK & SEE

Difference Between Allergy and non-Allergic Asthma:

Allergic asthma symptoms are similar to the non-allergy asthma ones. Both types of sufferers experience wheezing, coughing, chest tightness, chest pain or pressure, shortness of breath, sleep troubles. The early warning symptoms can be signs of frequent colds such as sneezing, sore throat, nasal congestion, running nose, or a permanent feeling of tiredness and bad mood. While both types of asthma manifest the same symptoms, the difference is made by the trigger of these symptoms. In case of allergic asthma, attacks are triggered by allergens such as pollens, pet dander, mold or dust. This is why all asthma sufferers need to be aware of their type of asthma, so they can apply preventive measures such as eating healthy foods and staying away from allergens. It is very important that allergic asthma sufferers try not to get in contact with the substances they are allergic to (allergens). These substances are easy to be determined by running some special tests, which any allergology lab can do.


Causes:

Asthma often runs in ‘atopic’ families. Children are also more likely to develop asthma if their mother smoked during pregnancy or while breastfeeding.

Most people find several things trigger their asthma. Some of the most common predisposing factors for asthma are allergies to:

•House dust mites
•Mould spores
•Pollen
•Pets
•Food or food preservatives

Asthma triggers include:

•Viral infections, such as colds and flu
•Cigarette smoke
•Certain forms of exercise, such as running
•Exposure to cold, dry air
•Laughing and other emotions
•Medication containing aspirin
•Drinks containing sulphur dioxide, such as squashes and lemon barley water

Treatment:
Some treatment can reduce both asthma and allergy symptoms, but most are designed to treat either one or the other. A few treatments can help with both conditions.

There are two main treatments for asthma:

•Relievers – salbutamol and terbutaline
•Preventers – beclomethasone, budesonide, fluticasone, mometasone and ciclesonide
These all come in a variety of delivery devices, such as aerosol or powder inhalers and nebulisers. You breathe the medicine in through your mouth, directly into your lungs.

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Relievers are drugs called bronchodilators (based on adrenaline) that relax the muscles which surround the airways, making it easier to breathe. You should take these as directed by your doctor as soon as symptoms appear.

Taking a dose of the reliever inhaler before exercise will increase your stamina and prevent breathing difficulty.

Preventers are drugs (usually low-dose steroids) that reduce inflammation in the airways and make them less sensitive. This means you’re less likely to react when exposed to a trigger.

The protective effect of this medicine is built up over a period of time, so you must take your preventer regularly, as directed by your doctor.

Combination preventer and long-acting reliever (formoterol and salmeterol) inhalers have become popular and seem to be particularly good at controlling more severe and persistent asthma.

If your asthma is really bad, your doctor may also prescribe a short course of steroid tablets to calm your inflamed airways.

Newer anti-inflammatory medication includes leukotriene receptor antagonists (montelukast and zafirlukast), which are particularly useful for brittle asthma and patients with aspirin-sensitive asthma.

The most recent addition to the list of possible treatments for asthma is a new injection medication (omalizumab) for those with severe allergic asthma, which works by dampening down the IgE allergic reaction.

An older orally administered bronchodilator, theophylline, isn’t often used these days owing to its unpredictable toxic side-effects and need for blood testing.

There is little scientific evidence to support the use of breathing exercises, such as Buteyko, in the treatment of asthma. However, some people with asthma find breathing exercises calm their symptoms and reduce their need for reliever medication.

You may need other medications to treat allergies or asthma, especially if your symptoms become severe at times. However, recognizing and avoiding the allergic substances that trigger your symptoms is the most important step you can take.

Who’s at risk of allergic asthma?
A family history of allergies is a major risk factor for allergic asthma. Having hay fever or other allergies yourself also increases your risk of getting asthma.

Allergic Asthma Preventive Measures:
If you’ve already been diagnosed with allery or allergic asthma, then you should also have a list of allergens you are sensitive to. It is not a joke, you need to stay away as much as you can from getting in contact with those allergens, if you want your allergic asthma not to bother you very often. Living a symptom-free life is possible in a big degree, but you need to understand how serious this allergic asthma issue has to be treated. Maybe this means that you’ll need to stay indoors in the days with high pollen activity, or maybe you won’t be allowed to eat strawberries again for the rest of your life. Understand that your lifestyle could change forever after you’ve found out that you suffer from allergy or allergic asthma.


Is all asthma caused by allergies?

Though allergic asthma is the one of the most common kinds of asthma, there are other types with different kinds of triggers. For example, for some people, asthma can be triggered by exercise, infections, cold air or gastroesophageal reflux disease (GERD). Many people have more than one kind of asthma trigger.

Pediatric Asthma
Pediatric asthma is one of the most delicate conditions that affect children of all ages. Before getting to the pediatric asthma treatment, we have to talk about the correct diagnosis, as this is a very hard thing to accomplish. Small children and infants cannot tell what bothers them, so the symptoms have to be guessed first by parents, and then by doctors. If a parent doesn’t suspect anything abnormal in their child, why would they seek for pediatric medical consultation? Children get frequent colds and childhood diseases, so there’s another reason for parents not getting too worried if their child coughs and has difficulties in breathing.

Can one prevent asthma?
You can help to avoid asthma attacks by taking preventer medicine regularly and avoiding your triggers. You can also monitor your asthma by asking your doctor to provide you with a peak flow meter, a simple device that measures the amount of breath in your lungs.

Most childhood asthma is caused by an allergy. Skin-prick and RAST tests may be able to discover the allergen. Practical steps can then be taken to avoid it, be it house dust mites, cats, dogs or other pets. Even mould spores and pollen grains can trigger seasonal asthma attacks.

If you’re prone to sudden or severe asthma attacks, keep asthma diary cards and a peak flow meter on hand to monitor your lung airflow so you can take early action.

Discuss an asthma action plan with your GP, who may issue an emergency supply of oral steroid pills. You may need to increase your medication dosage if your peak flow measurement drops steadily.

Remember, never stop taking your preventer medication, even when your symptoms are stable. Don’t wait until your symptoms get worse – they’ll be harder to treat.

By regular practicing Yoga  one can get rid of  Asthma totally

You may click to see :Yoga For Asthma Patients

You may click  for more informations  about Allergic Asthma :

Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.

Resources:

http://understandingasthma.com/
http://www.bbc.co.uk/health/physical_health/conditions/in_depth/allergies/allergicconditions_asthma.shtml
http://inflation.us/collegebubble.html
http://www.mayoclinic.com/health/allergies-and-asthma/AA00045

http://www.aafa.org/display.cfm?id=9&sub=16

http://alltruthabouthealth.info/allergic-asthma-is-the-type-of-asthma-problem/

http://www.poandpo.com/in-sickness-and-health/bronchial-and-allergic-asthma/

http://seerpress.com/causes-of-allergic-asthma-revealed/5423/

http://healthguide.howstuffworks.com/exercise-induced-asthma-picture-a.htm

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Vitamin B9 Treats Allergies, Asthma

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Folic acid, or vitamin B9, essential for the health of red blood cells and known to reduce the risk of spinal birth defects, may also  suppress allergic reactions and lessen the severity of allergy and asthma symptoms.

Johns Hopkins scientists, who conducted the first ever study examining the link between blood levels of folate, the naturally occurring form of folic acid and allergies, said results add to mounting evidence that folate can help regulate inflammation.

Recent studies, including research from Hopkins, have found a link between folate levels and inflammation-mediated diseases, including heart disease.

Cautioning that its far too soon to recommend folic acid supplements to prevent or treat people with asthma and allergies, researchers emphasise that more research needs to be done to confirm their results, and to establish safe doses and risks.

Reviewing the medical records of more than 8,000 people aged between two and 85 years, investigators tracked the effect of folate levels on respiratory and allergic symptoms and on levels of IgE antibodies, immune system markers that rise in response to an allergen.

People with higher blood levels of folate had fewer IgE antibodies, fewer reported allergies, less wheezing and a lower likelihood of asthma, researchers report.

“Our findings are a clear indication that folic acid may indeed help regulate immune response to allergens, and may reduce allergy and asthma symptoms,” said lead investigator Elizabeth Matsui.

“But we still need to figure out the exact mechanism behind it, and to do so we need studies that follow people receiving treatment with folic acid, before we even consider supplementation with folic acid to treat or prevent allergies and asthma.”

The current recommendation for daily dietary intake of folic acid is 400 micrograms for healthy men and non-pregnant women. Many cereals and grain products are already fortified with folate. Folate is also found naturally in green, leafy vegetables, beans and nuts, said a Hopkins release.

The study appeared online in the Journal of Allergy & Clinical Immunology.

Sources: The Times Of India

 
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Diagnonistic Test

Scratch Test for Allergies

allergy test 7/22/05
Image by scottobear via Flickr

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Definition:
For more than a century, doctors have used skin tests to help diagnose allergies. During these tests, your skin is exposed to allergy-causing substances (allergens) and then is observed for signs of an allergic reaction.

CLICK & SEE THE PICTURES

Along with your medical history, skin tests can confirm whether signs and symptoms, such as sneezing, wheezing and skin rashes, are caused by allergies. They can also identify the specific substances that trigger allergic reactions. Such information can help your doctor develop an allergy treatment plan that may include allergen avoidance, medications or allergy shots (immunotherapy).

This test checks for a skin reaction to common allergy-provoking substances, such as foods, molds, dust, plants, or animal proteins. If your skin reacts to a substance, chances are that you are allergic to it.

Most people with allergy symptoms don’t need testing because they can identify their triggers and control their symptoms with medicine. Your doctor might recommend scratch testing when you have severe allergy symptoms but are not sure what is causing them. Knowing what you are allergic to can help you avoid the substance in the future, and will help your doctor determine whether you might benefit from allergy shots.

Why it’s actually done?
Skin testing is widely used to diagnose allergic conditions such as hay fever, allergic asthma and dermatitis (eczema). It’s safe for people of all ages, including infants and older adults.

Sometimes, however, skin tests aren’t recommended. Your doctor may advise against skin testing if you:

*Take medications that interfere with test results. These include antihistamines, many antidepressants and some heartburn medications. Your doctor may determine that it’s better for you to continue taking these medications than to temporarily discontinue them in preparation for a test.

*Have a severe skin disease. If conditions such as eczema or psoriasis affect large areas of skin on your arms and back — the usual testing sites — there may not be enough clear, uninvolved skin to conduct an effective test.

*Are highly sensitive to suspected allergens. You may be so sensitive to certain substances that even the small amounts of them used in skin tests could trigger a severe allergic reaction (anaphylaxis).

Blood tests (technically called in vitro allergen-specific IgE antibody tests) are particularly useful for those who should not undergo skin tests. Although blood tests can be as accurate as skin tests, they’re not performed as often because they may be less sensitive and are more expensive. If you want to start immunotherapy — a series of injections intended to increase your tolerance to allergens — you need either a skin or blood test to identify the specific substances that trigger your allergies.
.What risks are there from the test?
Because the allergen exposure is so small, a serious allergic reaction is extremely unlikely.

The most common side effect of skin testing is itching and redness. This may be most noticeable during the test, when you aren’t allowed to scratch yourself.For a few hours you’ll probably have some redness or irritation on the testing sites, similar to having several mosquito bites. It usually subsides within a few hours, although it can persist until the next day. A mild cortisone cream can be applied to relieve the itching and redness.

Rarely, skin tests can produce a severe, immediate allergic reaction, so it’s important to have skin tests performed at an office where appropriate emergency equipment and medications are available. If you develop a severe allergic reaction in the days after a skin test, call your doctor right away.

Some doctors who practice complementary or alternative medicine may perform provocation-neutralization tests, but these tests aren’t proved and aren’t considered reliable.
.How you prepare for the test ?
Before recommending a skin test, your doctor will ask detailed questions about your medical history, your signs and symptoms, and your usual way of treating them. Your answers can help your doctor determine if allergies run in your family and if you might also have them.

Next, your doctor will perform a physical examination to search for additional clues about the causes of your signs and symptoms.

Your medical history and physical examination may provide enough information for your doctor to discuss your diagnosis and treatment. If so, a skin test may be unnecessary. But if your doctor is uncertain or suspects that you have allergies and needs more information about the possible causes, he or she may recommend that you have a skin test.

Before scheduling a skin test, your doctor will need a list of all your prescription and over-the-counter medications. Some medications can suppress allergic reactions preventing the skin testing from working effectively. Other medications may increase your risk of developing a severe allergic reaction during a test.

Because medications clear out of your system at different rates, your doctor may ask that you stop taking certain medications for up to 10 days. Medications that can interfere with skin tests include:

*Prescription nonsedating antihistamines, such as fexofenadine (Allegra) and cetirizine (Zyrtec)

*Over-the-counter antihistamines (Claritin, Benadryl, Chlor-Trimeton, others)

*Tricyclic antidepressants, such as amitriptyline and doxepin (Sinequan)

*Heartburn medications, such as cimetidine (Tagamet) and ranitidine (Zantac)

Tell your doctor if you have ever had anaphylaxis, a lifethreatening allergic reaction, or if you have had a serious reaction to a previous allergy test.

What happens when the test is performed?

In adults, the test is done on the forearm; in children it’s done on the upper back. (The child disrobes from the waist up and lies on his or her stomach.)

Your doctor decides what allergies are to be tested for. Some people are tested for as many as a few dozen at one visit. Individual drops of fluid are dripped in rows across the skin. The doctor uses a needle to make small light scratches in the skin under each drop, to help the skin absorb the fluid. The scratches aren’t deep enough to cause bleeding. Each drop contains proteins from a separate allergen (a substance, like ragweed pollen, that triggers allergy symptoms).Your doctor notes where each drop of fluid was placed, either by keeping a chart or by writing a code on the area of skin being tested.

For many people, the most difficult part of this test is next: You need to stay still long enough (usually about 20 minutes) to give the skin time to react. Your skin might tickle or itch during this time, but you won’t be allowed to scratch it. At the end of the waiting time, your doctor will examine each needle scratch for redness or swelling.

What must you do special after the test is over?
Nothing.

What you can expect from the test?
Contrary to what you may have heard, skin tests cause little if any discomfort. Because the needles used in these tests barely penetrate your skin’s surface, you won’t bleed or feel more than mild, momentary discomfort.

Some tests detect immediate allergic reactions, which develop within minutes of exposure to an allergen. Other tests detect delayed allergic reactions, which develop over a period of several days.

Procedure
Skin testing is usually performed in a doctor’s office. Typically, a nurse administers the test and a doctor interprets the results. The three main types of skin tests are:

*Puncture, prick or scratch test (percutaneous). In this test, which is the type of skin test most commonly performed, tiny drops of purified allergen extracts are pricked or scratched into your skin’s surface. This test is usually performed to identify allergies to pollen, mold, pet dander, dust mites, foods, insect venom and penicillin.

*Intradermal test (intracutaneous). Purified allergen extracts are injected into the skin of your arm. This test is usually performed if your doctor suspects that you’re allergic to insect venom or penicillin.

*Patch test (epicutaneous). An allergen is applied to a patch, which is then placed on your skin. This test is usually performed to identify substances that cause contact dermatitis. These include latex, medications, fragrances, preservatives, hair dyes, metals and resins.

Tests for immediate allergic reactions:
A puncture, prick or scratch test checks for immediate allergic reactions to as many as 40 different substances at one time. In adults, the test is usually done on the forearm. Children are usually tested on the upper back.

After cleaning the test site with alcohol, the nurse draws small marks on your skin and applies a drop of allergen extract next to each mark. He or she then uses a sharp instrument (lancet) to introduce the extracts into the skin’s surface. A new lancet is used for each scratch to prevent cross-contamination of allergens. The drops are left on your skin for 15 minutes, and then the nurse observes your skin for signs of allergic reactions.

To see if your skin is reacting the way it’s supposed to, the nurse introduces two additional substances into your skin’s surface:

*Histamine. In almost everyone, this substance causes a skin response, so it’s used as a positive control. If you don’t react to histamine, the skin test may be difficult or impossible to interpret.

*Glycerin or saline. In almost everyone, these substances cause no reaction. So one or the other is used as a negative control. If you react to glycerin or saline, you may have sensitive skin, so your reactions to the allergen extracts will need to be interpreted with caution.

You may need a more sensitive immediate-reaction test — known as an intradermal test — if a puncture, prick or scratch test is inconclusive. During this test, a nurse uses a thin needle and syringe to inject a small amount of allergen extract just below the surface of the skin on your arm. Then he or she inspects the site after 15 minutes for a local skin reaction.

Tests for delayed allergic reactions
Patch tests detect delayed allergic reactions. During a patch test, your skin may be exposed to 20 to 30 extracts of substances that can cause contact dermatitis. Caustic substances — such as industrial solvents — are diluted to prevent skin damage.

Allergen extracts are applied to bandages that you wear on your arm or back for 48 hours. During this time, you should avoid bathing and activities that cause heavy sweating. The bandages are removed when you return to your doctor’s office for an evaluation.

Results:
Before you leave the doctor’s office, you’ll know the results of a puncture, prick or scratch test or an intradermal test. A patch test may take several days or more to produce results.

If an allergen provokes an allergic reaction to a puncture or intradermal skin test, you’ll develop a raised, red, itchy bump (wheal and flare) that may look like a mosquito bite. A nurse will then measure the bump’s size.

After the nurse records the results, he or she will clean your skin with alcohol to remove the marks and allergen droplets. Then you’ll meet with your doctor to discuss the results and possible treatment options.

A positive skin test means that you may be allergic to a particular substance. Bigger bumps usually indicate a greater degree of sensitivity. A negative skin test means that you probably aren’t allergic to that particular allergen.

The accuracy of skin tests can vary. You may react differently to the same test performed at different times. Or you may react positively to a substance during a test but not react to it in everyday life.

In general, skin tests are most reliable for diagnosing allergies to airborne substances, such as pollen, pet dander and dust mites. Because diagnosing food allergies can be complex, you may need additional tests or procedures.


Resources:

https://www.health.harvard.edu/diagnostic-tests/allergies-scratch-test.htm
http://www.mayoclinic.com/health/allergy-tests/MY00131/UPDATEAPP=false&FLUSHCACHE=0

Categories
Ailmemts & Remedies

Anaphylaxis

Allergy skin testing
Image via Wikipedia

Definition:

Anaphylaxis is a rapidly progressing, life-threatening allergic reaction.It is a type of allergic reaction, in which the immune system responds to otherwise harmless substances from the environment. Unlike other allergic reactions, however, anaphylaxis can kill. Reaction may begin within minutes or even seconds of exposure, and rapidly progress to cause airway constriction, skin and intestinal irritation, and altered heart rhythms. In severe cases, it can result in complete airway obstruction, shock, and death.

Anaphylaxis is an acute systemic (multi-system) and severe Type I Hypersensitivity allergic reaction in humans and other mammals. The term comes from the Greek words ana (against) and phylaxis (protection). Minute amounts of allergens may cause a life-threatening anaphylactic reaction. Anaphylaxis may occur after ingestion, skin contact, injection of an allergen or, in rare cases, inhalation….CLICK & SEE

Anaphylactic shock, the most severe type of anaphylaxis, occurs when an allergic response triggers a quick release from mast cells of large quantities of immunological mediators (histamines, prostaglandins, leukotrienes) leading to systemic vasodilation (associated with a sudden drop in blood pressure) and edema of bronchial mucosa (resulting in bronchoconstriction and difficulty breathing). Anaphylactic shock can lead to death in a matter of minutes if left untreated.

An estimated 1.24% to 16.8% of the population of the United States is considered “at risk” for having an anaphylactic reaction if they are exposed to one or more allergens, especially penicillin and insect stings. Most of these people successfully avoid their allergens and will never experience anaphylaxis. Of those people who actually experience anaphylaxis, up to 1% may die as a result. Anaphylaxis results in approximately 18 deaths per year in the U.S. (compared to 2.4 million deaths from all causes each year in the U.S.). The most common presentation includes sudden cardiovascular collapse (88% of reported cases of severe anaphylaxis).

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Researchers typically distinguish between “true anaphylaxis” and “pseudo-anaphylaxis or an “anaphylactoid reaction.” The symptoms, treatment, and risk of death are identical, but “true” anaphylaxis is always caused directly by degranulation of mast cells or basophils that is mediated by immunoglobulin E (IgE), and pseudo-anaphylaxis occurs due to all other causes. The distinction is primarily made by those studying mechanisms of allergic reactions.

Causes:-
Anaphylaxis is a severe, whole-body allergic reaction. After an initial exposure (“sensitizing dose”) to a substance like bee sting toxin, the person’s immune system becomes sensitized to that allergen. On a subsequent exposure (“shocking dose”), an allergic reaction occurs. This reaction is sudden, severe, and involves the whole body.

Hives and angioedema (hives on the lips, eyelids, throat, and/or tongue) often occur. Angioedema may be severe enough to block the airway. Prolonged anaphylaxis can cause heart arrhythmias.

Some drugs (polymyxin, morphine, x-ray dye, and others) may cause an “anaphylactoid” reaction (anaphylactic-like reaction) on the first exposure. This is usually due to a toxic reaction, rather than the immune system mechanism that occurs with “true” anaphylaxis. The symptoms, risk for complications without treatment, and treatment are the same, however, for both types of reactions. Some vaccinations are also known to cause “anaphylactoid” reactions. Antitoxins and antivenins may cause similar reactions.

Anaphylaxis can occur in response to any allergen. Common causes include insect bites/stings, food allergies (peanuts and tree nuts are the most common, though not the only), and drug allergies. Pollens and other inhaled allergens rarely cause anaphylaxis. In opthamology, the dye fluorescein used in some eye exams is a well known trigger. Some people have an anaphylactic reaction with no identifiable cause.
Symptoms:-
Symptoms of anaphylaxis are related to the action of Immunoglobulin E (IgE) and other anaphylatoxins, which act to release histamine and other mediator substances from mast cells (degranulation). In addition to other effects, histamine induces vasodilation of arterioles and constriction of bronchioles in the lungs, also known as bronchospasm (constriction of the airways).

Tissues in different parts of the body release histamine and other substances. This causes constriction of the airways, resulting in wheezing, difficulty breathing, and gastrointestinal symptoms such as abdominal pain, cramps, vomiting, and diarrhea. Histamine causes the blood vessels to dilate (which lowers blood pressure) and fluid to leak from the bloodstream into the tissues (which lowers the blood volume). These effects result in shock. Fluid can leak into the alveoli (air sacs) of the lungs, causing pulmonary edema.

Symptoms can include the following:

*polyuria
*respiratory distress
*hypotension (low blood pressure)
*encephalitis
*fainting
*unconsciousness
*urticaria (hives)
*flushed appearance
*angioedema (swelling of the lips, face, neck and throat): this can be life threatening
*tears (due to angioedema and stress)
*vomiting
*itching
*diarrhoea
*abdominal pain
*anxiety

The time between ingestion of the allergen and anaphylaxis symptoms can vary for some patients depending on the amount of allergen consumed and their reaction time. Symptoms can appear immediately, or can be delayed by half an hour to several hours after ingestion. However, symptoms of anaphylaxis usually appear very quickly once they do begin.

Diagnosis:-

Anaphylaxis is diagnosed based on the rapid development of symptoms in response to a suspect allergen. Identification of the culprit may be done with RAST testing, a blood test that identifies IgE reactions to specific allergens. Skin testing may be done for less severe anaphylactic reactions.

The time between ingestion of the allergen and anaphylaxis symptoms can vary for some patients depending on the amount of allergen consumed and their reaction time. Symptoms can appear immediately, or can be delayed by half an hour to several hours after ingestion. However, symptoms of anaphylaxis usually appear very quickly once they do begin.

Apart from its clinical features, blood tests for tryptase (released from mast cells) might be useful in diagnosing anaphylaxis.

In some cases, it is unclear from the patient interview what triggered the anaphylaxis. In this setting, skin allergy testing (with or without patch testing) or RAST blood tests can sometimes identify the cause.

You may click to see:->Anaphylaxis Flow Chart

Treatment:-

Emergency Treatment
Anaphylaxis is a life-threatening medical emergency because of rapid constriction of the airway, often within minutes of onset, which can lead to respiratory failure and respiratory arrest. Brain and organ damage rapidly occurs if the patient cannot breathe. Due to the severe nature of the emergency, patients experiencing or about to experience anaphylaxis require the help of advanced medical personnel. First aid measures for anaphylaxis include rescue breathing (part of CPR). Rescue breathing may be hindered by the constricted airways, but if the patient stops breathing on his or her own, it is the only way to get oxygen to him or her until professional help is available.

.A woman being treated in an emergency department after going into anaphylactic shock

.The primary treatment for anaphylaxis is administration of epinephrine (adrenaline). Epinephrine prevents worsening of the airway constriction, stimulates the heart to continue beating, and may be life-saving. Epinephrine acts on Beta-2 adrenergic receptors in the lung as a powerful bronchodilator (i.e. it opens the airways), relieving allergic or histamine-induced acute asthmatic attack or anaphylaxis. If the patient has previously been diagnosed with anaphylaxis, he or she may be carrying an EpiPen or Twinject for immediate administration of epinephrine. However, use of an EpiPen or similar device only provides temporary and limited relief of symptoms.

Tachycardia (rapid heartbeat) results from stimulation of Beta-1 adrenergic receptors of the heart increasing contractility (positive inotropic effect) and frequency (chronotropic effect) and thus cardiac output.[10] Repetitive administration of epinephrine can cause tachycardia and occasionally ventricular tachycardia with heart rates potentially reaching 240 beats per minute, which itself can be fatal. Extra doses of epinephrine can sometimes cause cardiac arrest. This is why some protocols advise intramuscular injection of only 0.3–0.5mL of a 1:1,000 dilution.

Some patients with severe allergies routinely carry preloaded syringes containing epinephrine, diphenhydramine (Benadryl), and dexamethasone (Decadron) whenever they go to an unknown or uncontrolled environment.

You may click to see:->First Aid for Anaphylaxis
Clinical care
Paramedic treatment in the field includes administration of epinephrine IM; antihistamines IM (such as chlorphenamine or diphenhydramine); steroids, such as hydrocortisone or dexamethasone; IV Fluid administration and in severe cases, pressor agents (which cause the heart to increase its contraction strength) such as dopamine for hypotension, administration of oxygen, and intubation during transport to advanced medical care.

In severe situations with profuse laryngeal edema (swelling of the airway), cricothyrotomy or tracheotomy may be required to maintain oxygenation. In these procedures, an incision is made through the anterior portion of the neck, over the cricoid membrane, and an endotracheal tube is inserted to allow mechanical ventilation of the patient.

The clinical treatment of anaphylaxis by a doctor and in the hospital setting aims to treat the cellular hypersensitivity reaction as well as the symptoms. Antihistamine drugs such as diphenhydramine or chlorphenamine (which inhibit the effects of histamine at histamine receptors) are continued but are usually not sufficient in anaphylaxis, and high doses of intravenous corticosteroids such as dexamethasone or hydrocortisone are often required. Hypotension is treated with intravenous fluids and sometimes vasopressor drugs. For bronchospasm, bronchodilator drugs (e.g. salbutamol, known as Albuterol in the United States) are used. In severe cases, immediate treatment with epinephrine can be lifesaving. Supportive care with mechanical ventilation may be required.

It is also possible to undergo a second reaction prior to medical attention or using an Epipen. It is suggested to seek one to two days of medical care.

The possibility of biphasic reactions (recurrence of anaphylaxis) requires that patients be monitored for four hours after being transported to medical care for anaphylaxis.

Many anaphylactic patients will be sent home or released after the initial reaction is declared over. Yet, rebound reactions are almost always bound to happen. Most people with anaphylaxis have a rebound a few hours after the initial reaction, yet there are cases where a rebound would occur after as much time as a week.
Planning for emergency treatment:-
The Asthma and Allergy Foundation of America advises patients prone to anaphylaxis to have an “allergy action plan” on file at school, home, or in their office to aid others in case of an anaphylactic emergency, and provides a free “plan” form. Action plans are considered essential to quality emergency care. Many authorities advocate immunotherapy to prevent future episodes of anaphylaxis.

Beta-blockers may aggravate anaphylactic reactions and interfere with treatment.

Prognosis:
The rapidity of symptom development is an indication of the likely severity of reaction: the faster symptoms develop, the more severe the ultimate reaction. Prompt emergency medical attention and close monitoring reduces the likelihood of death. Nonetheless, death is possible from severe anaphylaxis. For most people who receive rapid treatment, recovery is complete.

Prevention:-
Immunotherapy with Hymenoptera venoms is especially effective and widely used throughout the world and is accepted as an effective treatment for most patients with allergy to bees, wasps, hornets, yellow jackets, white faced hornets, and fire ants.

Avoidance of the allergic trigger is the only reliable method of preventing anaphylaxis. For insect allergies, this requires recognizing likely nest sites. Preventing food allergies requires knowledge of the prepared foods or dishes in which the allergen is likely to occur, and careful questioning about ingredients when dining out. Use of a Medic-Alert tag detailing drug allergies is vital to prevent inadvertent administration during a medical emergency.

People prone to anaphylaxis should carry an “Epipen” or “Ana-kit,” which contain an adrenaline dose ready for injection.

The greatest success with prevention of anaphylaxis has been the use of allergy injections to prevent recurrence of sting allergy. The risk to an individual from a particular species of insect depends on complex interactions between likelihood of human contact, insect aggression, efficiency of the venom delivery apparatus, and venom allergenicity. According to most authorities, venom immunotherapy has been demonstrated to reduce the risk of systemic reactions below 1% to 3%. One simple method of venom extraction has been electrical stimulation to obtain venom, instead of dissecting the venom sac. An allergist will then provide venom immunotherapy which is highly efficacious in preventing future episodes of anaphylaxis.

A vaccine has been in the works to prevent anaphylaxis from peanuts and tree nuts. Despite showing significant promise to prevent individuals with the allergy from developing anaphylaxis if eating a small amount of the food, the FDA has not yet approved the vaccine.

You may click to see:->

Mast Cell Disorder

Allergy

Slow reacting substance of anaphylaxis

Exercise-induced anaphylaxis

.Paediatric Allergy – anaphylaxis

Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.

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