**9. Histopathology**

Skin biopsies of acute lesions demonstrate a minimal inflammatory infiltrate along with dilatation of small vessels, flattened rete pegs and swollen collagen fibers. Histology of chronic urticaria lesions reveals a perivascular cuffing by predominantly T lymphocytes and also monocytes, neutrophils, eosinophils and basophils [25].

Observation of fragmentation of neutrophils, red cell extravasation and swelling of endothelial cells in persistent lesions points to the diagnosis of leukocytoclastic vasculitis [13].
