Pityriasis amiantacea L21.0

Polyätiological clinical picture of the capillitium with the formation of asbestos-like, micaceous, grey-white shimmering, dry or greasy scaly deposits, which surround the head hair in different lengths. The disease is often accompanied by tuft-like hair loss.

Polyetiological, e.g. occurring in seborrhea, atopic eczema, pediculosis, impetigo, psoriasis vulgaris. Pityriasis amiantacea in combination with folliculitis decalvans has been described as a paradoxical side effect of treatment with TNF-alpha antagonists (Zamperetti M et al. 2017).

In case of prolonged untreated asbestos-related scalp infestation, irreversible (scarring) hair loss may occur. In this case, the hair falls out in clumps or can simply be pulled out of the scalp without pain.

Desquamative therapy with salicylic acid-containing externals such as 10% salicylic acid oil/ointment (Rp221) or salicylic acid oil 2/5 or 10% with triamcinolone acetonide 0.1%. Apply the salicylic acid-containing oil liberally to the scalp. Then cover the entire capillitium with a foil for several hours, if possible, and fix it with a tubular bandage (a terry cloth cap or a cotton cap, also surgical cap, is sufficient). Repeat the identical procedure the next day; after 2-3 days (daily is also possible) thoroughly wash out scalp hair. Any dandruff can be combed out with a large comb without pulling it tightly.

Alternative: After this primary keratolytic treatment, an occlusive treatment with topical glucocorticoids in O/W bases, such as triamcinolone cream(e.g. Triamgalen, Rp259 ) or a glucocorticoid-containing gel such as 0.05% betamethasone gel (e.g. Diprosis Gel) has proven effective. Subsequently, mechanically detach scale plaques again.

Alternatively: local applications with a tar-containing externum (5%-10% Liquor carbonis detergens in Lygal head ointment).

Subsequently, keratolytic maintenance therapy (1 time/week, if necessary every 2 weeks) should be used to reduce the formation of dandruff plaques. In addition, special anti-dandruff shampoos (e.g. de-Squam®, Almirall). Alternatively, a tar-containing shampoo could be used (e.g. Tarmed® shampoo with 4% added tar; available again by prescription since June 2015).

Comment: It is important to make patients aware that pityriasis amiantacea is often accompanied by hair loss (scarring alopecia), which may become more noticeable during a phase of intensified local therapy.

1. Abdel-Hamid IA et al (2003) Pityriasis amiantacea: a clinical and etiopathologic study of 85 patients. Int J Dermatol 42: 260-264
2. Bettencourt MS, Olsen EA (1999) Pityriasis amiantacea: a report of two cases in adults. Cutis 64: 187-189
3. Ginarte M (2000) Case Reports. Pityriasis amiantacea as manifestation of tinea capitis due to Microsporum canis. Mycoses 43: 93-96
4. Gschwandter WR (1973) Porrigo amiantacea (Pityriasis amiantacea). dermatologist 256: 134-139