Evidence for a functional defect of the lamina lucida in recessive dystrophic epidermolysis bullosa demonstrated by suction blisters.

Suction blisters were raised in non-lesional skin of sixteen patients with various types of epidermolysis bullosa (EB). The ultrastructural level of separation was found in each type to be within the lamina lucida of the epidermal basement membrane zone. Suction blister times were normal in EB simplex, dominant dystrophic and localized recessive dystrophic EB, but were markedly reduced in both junctional EB and severe generalized recessive dystrophic EB. These data indicate an unpredicted abnormality of adhesion within the lamina lucida in severe recessive dystrophic EB, in addition to the well-recognized defect at a deeper level, beneath the lamina densa, in this condition. The use of suction blister times may prove valuable in the diagnosis of EB.