Red scalp plaque with painful ulceration

The parents of a white infant, aged 3 months, were concerned about a lesion on the child's scalp. A very small bruise-like lesion was ­present at birth; the pediatrician thought it was caused by trauma from delivery.

At age 3 weeks, however, the "bruise" became a pink patch that grew into a firm, rubbery, red, and slightly blanchable nodule over ...