Placebo-controlled study of the efficacy of topical antihistaminics against histamine-induced pruritus.

2 antipruritic ointments, when compared to placebo, were ineffective against histamine-induced itching applied in 2 volunteers after the intracutaneous injection of histamine. Testing of 11 topical antihistaminics after pretreatment for 30 and 60 min on 12 volunteers showed that some of the preparations reduced the histamine-induced itching significantly, while others were able to inhibit itching only slightly or were very close to placebo. Pain from pin pricks could not be attenuated significantly by pretreatment with the topical antihistaminics at any time.