Pityriasis rosea

Definition:
Some people say Pityriasis rosea (also known as “Pityriasis rosea Gibert“) is a skin rash. It is non-dangerous but may inflict substantial discomfort on some sufferers.  Classically, it begins with a single “herald patch” lesion, followed in 1 or 2 weeks by a generalized body rash lasting about 6 weeks

Pityriasis rosea is common type of skin rash seen between the ages of ten and 35. It is a skin rash that often sweeps out from the middle of your body, with a shape that resembles drooping pine-tree branches. Pityriasis (pit-ih-RI-uh-sis) rosea usually begins as one large spot on your chest, abdomen or back and then spreads.

The cause isn’t known, but a viral infection is suspected (though it doesn’t seem to be contagious).The overall prevalence of  Pityriasis rosea in the United States has been estimated to be 0.13% in men and 0.14% in women.
You may click to see Pictures of Pityriasis rosea
Symptoms:
The symptoms of Pityriasis rosea include:

*An upper respiratory tract infection may precede all other symptoms in as many as 69% of patients

*A single, 2- to 10-cm oval red “herald” patch appears, classically on the abdomen.  Occasionally, the”herald” patch may occur in a ‘hidden’ position (in the armpit, for example) and not be noticed immediately. The “herald” patch may also appear as a cluster of smaller oval spots, and be mistaken for acne. Rarely, it does not become present at all.

*7-14 days after the herald patch, large patches of pink or red, flaky, oval-shaped rash appear on the torso. In 6% of cases an inverse distribution may occur, with rash mostly on the extremities. The more numerous oval patches generally spread widely across the chest first, following the rib-line in a characteristic “christmas-tree” distribution.  Small, circular patches may appear on the back and neck several days later. It is unusual for lesions to form on the face, but they may appear on the cheeks or at the hairline.

*About one-in-four people with PR suffer from mild to severe symptomatic itching. (Moderate itching due to skin over-dryness is much more common, especially if soap is used to cleanse the affected areas.) The itching is often non-specific, and worsens if scratched. This tends to fade as the rash develops and does not usually last through the entire course of the disease.

*The rash may be accompanied by low-grade fever, headache, nausea and fatigue. Over-the-counter medications can help manage these

Causes:
The cause of pityriasis rosea is not certain, but its clinical presentation and immunologic reactions suggest a viral infection as a cause.  Also, HHV-7 is frequently found in healthy individuals, so its etiologic role is controversial.

It is not contagious,  though there have been reports of small epidemics in fraternity houses and military bases, schools and gyms.

Complications:
Complications of pityriasis rosea aren’t likely, but if they do occur, they may include:

*Severe itching
*Lasting brown spots after the rash has healed, on dark skin

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Diagnosis:
Identification of pityriasis rosea can be challenging for a number of reasons. The diagnosis is unclear at the onset of symptoms, and there are no noninvasive tests that confirm the condition. In at least one half of patients, the first symptoms of pityriasis rosea are nonspecific and consistent with a viral upper respiratory infection.1,5 A herald patch then appears, typically on the trunk. This large lesion is commonly 2 to 10 cm in diameter, ovoid, erythematous, and slightly raised, with a typical collarette of scale at the margin.....PIC-1 . At this stage, however, the diagnosis usually remains unclear. Microscopic examination of potassium hydroxide preparations shows no fungal elements. The lesion cannot be differentiated from eczema and often is treated as such.

A few days to a few weeks after the appear ance of the herald patch, crops of smaller lesions, 5 to 10 mm in diameter, develop across the trunk and, less commonly, on the extremities. These lesions are salmon colored, ovoid, raised, and have the same collarette of scale as the herald patch.…PIC-2... . At this stage, the diagnosis usually is clear, particularly if the physician can observe or elicit a history of the herald patch.
If the diagnosis is uncertain, especially if the palms and soles are affected and the patient is sexually active, the physician should consider the possibility of secondary syphilis. Appropriate evaluation includes direct fluorescent antibody testing of lesion exudates, a VDRL test, or dark-field microscopy.11 Other conditions in the differential diagnosis include diffuse nummular eczema, tinea corporis, pityriasis lichenoides, guttate psoriasis, viral exanthem, lichen planus, and medication reaction.

The smaller secondary lesions of pityriasis rosea follow Langer’s lines ..PIC-3.. When the lesions occur on the back, they align in a typical “Christmas tree” or “fir tree” pattern. Elsewhere on the body, the lesions follow the cleavage lines as follows: transversely across the lower abdomen and back, circumferentially around the shoulders, and in a V-shaped pattern on the upper chest12...PIC-4. Pruritus is variable. Except for mild to severe itching in 25 percent of patients, no systemic symptoms typically are present during the rash phase of pityriasis rosea.

Biopsy usually is not indicated in the evaluation of patients with suspected pityriasis rosea. Histology has shown that in addition to non-specific subacute and chronic inflammation, 55 percent of specimens contain epidermal cells that display dyskeratotic degeneration.14

Worsening of the rash or a second wave of lesions is not uncommon before eventual spontaneous resolution of the eruption. Recurrence of the condition later in life is rare.

Although no causal link has been established, multiple drugs have been associated with an extensive and often prolonged form of pityriasis rosea . A review of the literature shows that single case reports account for most of the drug associations.

Treatment:
No treatment is usually required.

Oral antihistamines or topical steroids may be used to decrease itching.[5] Steroids do provide relief from itching, and improve the appearance of the rash, but they also cause the new skin that forms (after the rash subsides) to take longer to match the surrounding skin color. While no scarring has been found to be associated with the rash, itching and scratching should be avoided. Irritants such as soap should be avoided, too; a soap containing moisturizers (such as goat’s milk) may be used, however, any generic moisturizer can help to manage over-dryness.

Direct sunlight makes the lesions resolve more quickly. According to this principle, medical treatment with ultraviolet light has been used to hasten resolution, though studies disagree whether it decreases itching or not. UV therapy is most beneficial in the first week of the eruption

Prognosis:
In most patients, the condition lasts only a matter of weeks; in some cases it can last longer (up to six months). The disease resolves completely without long-term effects. Two percent of patients have recurrence.

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.bbc.co.uk/health/physical_health/conditions/pityriasisrosea.shtml
http://www.nlm.nih.gov/medlineplus/ency/article/000871.htm
http://www.mayoclinic.com/health/pityriasis-rosea/DS00720
http://www.aafp.org/afp/2004/0101/p87.html
http://en.wikipedia.org/wiki/Pityriasis_rosea

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