The Histopathology of Urticaria Revisited—Clinical Pathological Study

Histological findings in classical urticaria show a spectrum of findings from a sparse superficial perivascular to a deep perivascular and interstitial infiltrate. Distinctive groups based on the dominant cell type can be identified, accounting for the similarity to neutrophilic urticarial dermatosis. Lesions may have a purpuric appearance, but leukocytoclastic vasculitis is never present.