Annular and linear brown patches in axillae

Recent laboratory data, including blood cell count, renal and liver function, serum electrolyte levels, fasting blood sugar levels, urinalysis, and serological examinations for human hepatitis viruses and syphilis, were all within normal limits or negative. Casual relationships, including drugs, sun exposure, internal malignancy, liver disease, impaired carbohydrate metabolism, and race have been proposed to explain the pathogenesis. The lesions in ashy dermatosis show a characteristic bluish-gray color, related with the presence of melanophages in deep dermis, and the inflammatory infiltrate does not acquire the band-like pattern of the LPP and LPP-inv.