ABSTRACT
Amyloidosis is a disorder of protein metabolism characterized by the extracellular deposition of abnormal protein fibrils. We report a case of macular amyloidosis due to nylon towel on his back. A 61-year-old male presented with asymptomatic hyperpigmented macules on the scapulae for 6 years. He had a habit of scrubbing his back for many years with a rough nylon towel while taking a bath. The histologic examination revealed liquefaction degeneration and homogenous eosinophilic deposition in the papillary dermis. In Congo red, amyloid material stained positively and in anti-keratin antibody staining. He had neither clinical nor laboratory evidence of systemic amyloidosis. A diagnosis of friction amyloidosis was made on histological and immunohistopathological findings.