Pityriasis amiantacea
Last Updated: 2025-02-11
Author(s): Rahel Bianchi
ICD11: EG30.2
Last Updated: 2025-02-11
Author(s): Rahel Bianchi
ICD11: EG30.2
Alibert, 1832
Asbestos grind
Fausse teigne amiantacé
Impetigo scabida
Keratosis follicularis amiantacea
Keratosis follicularis contagiosa
Porrigo amiantacea
Taenia amiantacea
Teigne amiantacé
Tinea amiantacea
Polyetiological disease of the scalp occurring in circumscribed areas with asbestos-like, grey-white, mica-like shimmering dandruff deposits that surround the scalp hair and often lead to a temporary loss of the same.
It can occur at any age, but adolescents and young women are particularly affected
Psoriasis is the most common underlying disease associated with pityriasis amiantacea, followed by seborrhoeic and atopic dermatitis. Pityriasis can precede psoriasis.
It is a polyetiological condition with an incompletely understood aetiopathogenesis, whereby a maximum variant of pityriasis simplex is currently assumed. Often there is already an underlying skin disease and pityriasis occurs as a secondary clinical picture. An increased incidence has been demonstrated in psoriasis vulgaris or capitis, seborrhoea, atopic eczema, pediculosis or impetigo. Occurrence in lichen planus and Darier’s disease has also been described in case studies.
Asbestos-like, grey-white, mica-like shimmering scaling, which partially surrounds the hair and adheres to the scalp
Only a circumscribed part of the scalp is affected
Non-scarring alopecia
Possibly secondary signs of infection with permanent hair loss, whereby the hair can be painlessly detached from the scalp.
Clinical diagnosis
Hair-bearing areas of the capillitium
Permanent, scarring hair loss
The prognosis is generally good. If the disease remains untreated for a long time, it can lead to permanent hair loss, which is usually due to secondary infections with streptococci or staphylococci.
Primary keratolytic treatment with local therapy containing salicylic acid, e.g. using 10% salicylic acid oil/ointment (Rp221) or salicylic acid oil 2/5 or 10% with triamcinolone acetonide 0.1%. Care must be taken to ensure an exposure time of several hours, a final covering of the capillitium with film and adequate fixation, e.g. with a tubular bandage. The application can be repeated after 2-3 days. The hair must be washed out thoroughly.
Alternative: Tar-containing external agent e.g. 5%-10% liquor carbonis detergens in Lygal head ointment
If necessary, an occlusive treatment with topical glucocorticoids such as triamcinolone cream or 0.05% betamethasone gel can be carried out after keratolysis. The resulting scaly plaques should be removed mechanically.
After acute therapy, maintenance therapy should be carried out every 1-2 weeks to prevent the formation of new scales.
Affected people benefit from anti-dandruff shampoos such as de-Squam®, Almirall. Alternatively, a tar-containing shampoo such as Tarmed® shampoo with 4% added tar is suitable.
At the start of treatment, the patient should be informed that the hair loss caused by the disease may become more noticeable.
