Periumbilical perforating pseudoxanthoma elasticum.

A 58-year-old, gravida 6, obese woman presented with a pruritic yellowish plaque around the umbilicus, which first appeared about 3 years ago. She also had flat yellow papules on the axilla and neck. After a burn from a heating device, a few perforating papules and a violaceous hue occurred on the plaque. Histological examination revealed pathological elastic fibers with a keratotic plug and perforation in the deep dermis, which was consistent with perforating pseudoxanthoma elasticum. This case indicates that perforating pseudoxanthoma elasticum, a variant of hereditary pseudoxanthoma elasticum may perforate due to mechanical factors.