Topically applied aspirin decreases histamine-induced wheal and flare reactions in normal and SLS-inflamed skin, but does not decrease itch. A randomized, double-blind and placebo-controlled human study.
Topically applied aspirin has recently been reported to decrease histamine-induced itch in human volunteers. Our aim is to confirm this and to study the antipruritic ability of topical aspirin in inflamed skin. In 24 non-atopic volunteers, an inflammatory skin reaction was induced in forearm skin at 5 different sites by sodium lauryl sulphate contained in Finn Chambers. Aspirin 10%, aspirin 1%, mepyramine 5% and vehicle were applied to the inflamed and corresponding non-inflamed areas 20 min before itch induction with intradermal histamine injection. Itch and pain were scored on a visual analogue scale at regular intervals. Wheal and flare areas were measured. No difference in itch intensities was found after application of aspirin, mepyramine and vehicle, but more itch was induced in aspirin and mepyramine pretreated sites in inflamed skin compared to normal skin (p<0.05). In normal skin, flare areas were smaller after pretreatment with aspirin 10% (p<0.05) and mepyramine (p<0.001), as were wheal areas after mepyramine (p<0.01), compared to vehicle pretreatments. In inflamed skin, flare areas were smaller after pretreatment with aspirin 10% (p<0.01) and mepyramine (p<0.001), as were wheal areas after aspirin 10% (p<0.01), aspirin 1% (p<0.05) and mepyramine (p<0.001). We conclude that despite a significant skin penetration as measured by the influence on wheal and flare reactions, topically applied aspirin did not decrease histamine-induced itch in the model used.
Thomsen
J S
JS
Department of Dermatology, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark. jeth@gentoftehosp.kbhamt.dk
Benfeldt
E
E
Jensen
S B
SB
Serup
J
J
Menné
T
T
D000287:Administration, Topical; D000328:Adult; D000704:Analysis of Variance; D001241:Aspirin / Q000008:administration & dosage*; D017453:Dermatitis, Irritant / Q000188:drug therapy*; D004311:Double-Blind Method; D005260:Female; D006632:Histamine / Q000494:pharmacology*; D006801:Humans; D007271:Injections, Intradermal; D008297:Male; D010146:Pain / Q000139:chemically induced / Q000188:drug therapy / Q000503:physiopathology*; D011336:Probability; D011446:Prospective Studies; D011537:Pruritus / Q000139:chemically induced / Q000188:drug therapy*; D011738:Pyrilamine / Q000008:administration & dosage*; D012016:Reference Values; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012882:Skin Tests; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D016896:Treatment Outcome
D012967:Sodium Dodecyl Sulfate; D006632:Histamine; D011738:Pyrilamine; D001241:Aspirin