Pityriasis amiantacea: a clinical and etiopathologic study of 85 patients

Abstract

Pityriasis amiantacea represents a particular reaction pattern of the scalp to various inflammatory scalp diseases. The most frequent skin diseases associated with PA are psoriasis and seborrheic dermatitis. It is important to keep the diagnosis of tinea capitis in mind when evaluating PA patients. Staphylococci on the scalp could participate in the pathogenesis of PA.

Pityriasis amiantacea: a study of seven cases

“…In the present study, psoriasis accounted for 35.3% of the cases; aggregated seborrheic dermatitis and atopic eczema for 34.2%; tinea capitis – diagnosed by mycological examination – for 12.9% of cases. 2 Our research revealed that 11.1% of seborrheic dermatitis patients had pityriasis amiantacea during follow-up. Unlike the 42% described in the literature, 5 all 63 patients presented with scalp involvement in our study.…”

“…Patients possibly present some sort of genetic or environmental predisposition for the disease. 1,2 Among the possible causes, we underline atopic and seborrheic dermatitis, psoriasis, and tinea capitis. However, it is known that the disease presents no associated dermatitis in certain cases.…”

Dermoscopy as a useful supportive tool for the diagnosis of pityriasis amiantacea-like tinea capitis

“…Clinical distinction between PA due to inflammatory noninfectious diseases and PA-like tinea capitis is a challenging task, with a significant likelihood of diagnostic errors/delays and prescription of inappropriate therapies [1,2]. Over the last few years, dermoscopy has been showed to be a useful auxiliary instrument for the recognition of several hair disorders [8–9], particularly dermatophyte infections [3–7].…”

“…Pityriasis amiantacea (PA) is a scalp disorder presenting with thick, silvery/yellowish, asbestos-like scales wrapping around and binding down tufts of hair [1]. It is typically considered to be a reactive condition to several inflammatory diseases, which may affect the scalp, mainly including psoriasis, atopic dermatitis and seborrheic dermatitis [1].…”

“…It is typically considered to be a reactive condition to several inflammatory diseases, which may affect the scalp, mainly including psoriasis, atopic dermatitis and seborrheic dermatitis [1]. However, although rarely, PA may be the presenting clinical pattern of dermatophyte infection (PA-like tinea capitis), thus emphasizing the importance of ruling out/confirming the possibility of tinea capitis when dealing with a case of PA [1,2] We here describe for the first time the usefulness of dermoscopy as a supportive diagnostic tool in an instance of PA-like tinea capitis.…”