To the Editor.—
Pityriasis amiantacea (PA) is a localized, noninflammatory scaling disease of the scalp with an unknown cause. Alibert1 first characterized this condition in 1832 as an asbestoslike tinea. Patients typically present with thick, greasy, or heavy scales localized to areas on the vertex, which may grow onto and surround hairs. These sites may or may not be associated with a characteristically nonscarring alopecia. Many conditions are associated with PA including psoriasis, atopic dermatitis, seborrheic dermatitis, tinea, eczema, pyoderma, pediculosis, and alopecia areata,2-4 although these relationships are uncertain. Culture, potassium hydroxide preparation, and examination under Wood's light typically show negative findings.2,3Few reports of this disease have been published in the English-language medical literature, including only one known report, in 1929, in the US literature.4 Ten cases are described to further characterize and make physicians more aware of this not-uncommon condition.
Report of Cases.—
All 10 patients were identified with PA from
Ring DS, Kaplan DL. Pityriasis Amiantacea: A Report of 10 Cases. Arch Dermatol. 1993;129(7):913-914. doi:10.1001/archderm.1993.01680280103030