Pityriasis rosea and sarcoidosis
Pityriasis rosea is an inflammatory skin condition characterised by diffuse scaly papules or plaques. Treatment is usually not required.
Pityriasis rosea most often occurs between the ages of 10 and 35. It is more common in women and has its highest incidence during the colder months in temperate climates. A viral infection may be involved.
Symptoms and signs
The condition classically begins with one primary “herald patch”, 2–10 cm in diameter, on the trunk or proximal limbs. After 7–14 days, a generalised centripetal eruption of pink to brown oval papules and plaques appears, usually 0.5–2 cm in diameter. The lesions have a fine, slightly raised collarette of scale and may resemble tinea corporis. Most people experience itching, which may occasionally be severe.
In people with darker skin, children and pregnant women, papules with little or no visible scaling may predominate. The pink or brown colour may be less apparent in darker skin. An inverse form may affect the armpits or groin and spread outward. Lesions classically follow the lines of the skin, producing a “Christmas-tree” pattern on the back. A minority of patients experience malaise or headache before the rash appears.
Diagnosis
Diagnosis is based on the clinical appearance and distribution. Differential diagnoses include tinea corporis, tinea versicolor, drug eruptions, psoriasis, parapsoriasis, pityriasis lichenoides chronica, lichen planus and secondary syphilis. Syphilis serology is indicated when the palms or soles are involved, when the herald patch is not seen, or when the lesions appear in an unusual order or distribution.
Treatment
Treatment is usually unnecessary because the eruption generally resolves within about five weeks and recurrence is uncommon. Artificial or natural sunlight may accelerate resolution. Itching can be treated when necessary with topical corticosteroids, oral antihistamines or other local measures.
The source text describes pityriasis rosea as a possible consequence of reduced immunity. This should not be interpreted as proof that sarcoidosis caused the rash; the relationship is not established for every patient.
Source: http://www.msd-prirucnici.placebo.hr/msd-prirucnik/dermatologija/psorijaza-i-bolesti-pracene-ljuskanjem/pityriasis-rosea
This page is educational and does not replace an examination or individual medical advice.