title: Elevated blood histamine levels and mast cell degranulation in solar urticaria.
abstract: 1 Ultraviolet radiation (UVR)-induced wealing was studied in four patients with solar urticaria, whose measured action spectra were within the range 300 to 700 nm. 2 Elevated histamine levels were found in blood draining wealed skin in all four patients. 3 Histological and electron microscopial studies of the irradiated skin showed evidence of mast cell degranulation. 4 These findings demonstrate an association between histamine release from mast cells and wealing in solar urticaria, and should encourage evaluation of drugs which suppress histamine release in this disorder.
mesh_terms: D000328:Adult; D003594:Cytoplasmic Granules / Q000502:physiology; D005260:Female; D006632:Histamine / Q000097:blood*; D006801:Humans; D008297:Male; D008407:Mast Cells / Q000648:ultrastructure*; D013472:Sunlight; D013997:Time Factors; D014466:Ultraviolet Rays / Q000009:adverse effects; D014581:Urticaria / Q000097:blood* / Q000209:etiology / Q000473:pathology
chemical_list: D006632:Histamine