Skin hyperpigmentation from chronic arsenic poisoning

A 34-year-old woman presented to the general medicine clinic with a 3-year history of changes in skin color. Examination was notable for innumerable hypopigmented macules on a background of hyperpigmentation, creating a raindrop-like appearance on the chest (panel A) and back. The palms (panel B) and soles had similar changes in pigmentation, as well as hyperkeratotic papules.