This 70 year old man presented with pruritic grouped vesicles on his extensor surfaces. This is a characteristic presentation with great pathology. The histology in this case is classic, with aggregates of neutrophils in the dermal papillae. The immunofluoresence was performed and confirmed the presence of IgA deposition in these papillae, but the diagnosis could be made on H&E. The differential diagnosis includes linear IgA disease, but the prominent dermal papillary aggegates would be unusual for that entity.
At higher power, there is a classic display of neutrophilic aggregates in the dermal papillae. Neutrophils also align along the junction. Scattered eosinophils are also noted.