Transient Bullous Dermolysis of the Newborn

A black male newborn developed large bullae on his extremities and other friction areas shortly after birth, which healed rapidly without scarring but left hypopigmentation. New lesions appeared occasionally for four months but ceased thereafter. At 12 months, the infant was healthy with only residual hypopigmentation. Histologic and electron microscopic examinations showed a subepidermal bulla due to subbasal lamina separation, caused by collagenolysis and damage to anchoring fibrils. The perifollicular collagen sheath was damaged, but the periductal collagen of the eccrine duct remained intact. Keratinocytes in the lower epidermis had large, dilated rough endoplasmic reticulum (RER) containing electron-dense stellate bodies, suspected to contain proteolytic enzymes responsible for collagenolysis. The severity of collagenolysis correlated with the number and size of RER vacuoles.