Piggyback-acquired hypertrichosis.

A 9-month-old girl exposed to 5% topical minoxidil for 2 months developed generalized hypertrichosis of the exposed and unexposed areas of her body. The infant's grandfather had been using minoxidil daily and then propping the baby on his shoulders for an hour or more a day. Minoxidil was eliminated from the child's environment and 4 months later her hair distribution returned to normal.