Pityriasis amiantacea.

Pityriasis amiantacea is an easily recognizable cutaneous disease that is characterized by scaling of the scalp and temporary alopecia. The scaling, described as thick and asbestos-like, binds down tufts of hair. The alopecia may be temporary or scarring. Despite a well-established clinical description, no definitive etiology has been uncovered. This disease may represent seborrheic dermatitis, superficial fungal or pyogenic infections, lichen planus, or psoriasis. Histologically, the disease is characterized by eczematous features. We report a case of pityriasis amiantacea in an 11-year-old girl with simultaneous findings of psoriasis as well as review the literature on the etiology of this disease.