Biphasic amyloidosis arising from friction melanosis.

摘要: A 40-year-old woman who had used nylon towels in the bath for about 10 years noticed hyperpigmentation on prominent regions over bones of trunk and extremities. She also developed lichenoid papules with itching her back. Histologically, both pigmented papular lesions amyloid deposits beneath epidermis. In this case it is presumed that (lichen amyloidosus) initially from friction melanosis which became macular lesion (macular amyloidosis). The etiologic factor these sequential pathologic changes considered to be repeated scrubbing towels.