Laptop computer-induced hyperpigmentation.

A 25-year-old afebrile man presented with one year of worsening non-pruritic hyperpigmented non-blanchable reticulated patches and one erosion on his abdomen. He denied trauma, contact with new detergents, and recent travel. He was not taking medications and denied ever having similar skin findings. Further questioning revealed that he positioned his laptop computer directly on his abdomen for several hours every night. His progressive skin findings characterize erythema ab igne, which occurs after repetitive prolonged exposure to temperatures between 43 to 47 degrees Celsius. The hyperpigmentation can occur anywhere on unprotected skin and is an ongoing clinical problem in all demographics as heat sources evolve. Guided questioning of an unsuspecting patient can expedite diagnosis and prevent the development of erosions and ulcers, permanent skin discoloration, and even skin cancers.