title: The cellular inflammatory response in nicotinate skin reactions.
abstract: Sequential skin biopsies of nicotinate-treated skin from nine normal subjects, three aspirin-pretreated normal subjects and six atopic eczema patients were examined. An erythematous skin reaction was seen in the nine normal subjects and to a lesser degree in one atopic eczema patient, but not in the aspirin-pretreated subjects nor in five remaining atopics. Accumulation of a mononuclear cell perivascular infiltrate was seen from 15 min onwards in the normal subjects. Neutrophils became the predominant cell invading thickened vessel walls and in the perivascular space beginning at 2 h and persisting up to 48 h. Leucocytoclasis was observed at 24 h. Immunofluorescence studies showed only non-specific fibrinogen deposits in papillary capillaries in the three groups of subjects. The chloroacetate esterase reaction and immunohistochemical labelling with OKM I confirmed a marked neutrophilia at 2 h and 24 h. Neutrophils were seen in one atopic eczema patient, but were not observed in the remainder, nor in the skin of the aspirin-pretreated normal subjects. Topical application of nicotinate causes non-allergenic, leucocytoclastic vascular damage in normal skin which can be inhibited by aspirin and which is reduced or absent in atopic eczema.
mesh_terms: D000328:Adult; D001241:Aspirin / Q000494:pharmacology; D003876:Dermatitis, Atopic / Q000188:drug therapy* / Q000473:pathology; D004890:Erythema / Q000139:chemically induced; D005260:Female; D005663:Furans / Q000009:adverse effects* / Q000037:antagonists & inhibitors; D006801:Humans; D007249:Inflammation / Q000139:chemically induced / Q000473:pathology; D007958:Leukocyte Count; D008297:Male; D008407:Mast Cells; D008875:Middle Aged; D009504:Neutrophils; D009539:Nicotinic Acids / Q000009:adverse effects* / Q000037:antagonists & inhibitors; D012867:Skin / Q000187:drug effects* / Q000473:pathology
chemical_list: D005663:Furans; D009539:Nicotinic Acids; C005813:thurfyl nicotinate; D001241:Aspirin