A case of pretibial dystrophic epidermolysis bullosa: decreased expression of the non-helical domain of type VII collagen molecule.

A 27-year-old man with an ataxic gait due to infantile cerebral paralysis exhibited recurrent blistering caused by mechanical stimuli on the pretibial area of both legs from the age of 20. His parents were not consanguineous, and he had no relatives who suffered from blistering. The histology showed a subepidermal bulla due to dermolytic epidermal-dermal separation. The anchoring fibrils were sparse and rudimentary in the predilection area. An LH 7:2 monoclonal antibody against the non-helical domain of the type VII collagen molecule stained the basement membrane zone of the patient's skin at a weaker intensity than the staining of normal human skin, but at a distinctively stronger intensity than the staining of skin from a patient with recessive dystrophic epidermolysis bullosa. Immunoelectron microscopy revealed that LH 7:2-immunoreactants were distributed irregularly within the lamina densa and sparsely in the sublamina densa region. The patient was diagnosed with pretibial dystrophic epidermolysis bullosa.