ALCOHOL VEHICLES IN TESTS FOR NONIMMUNOLOGICAL IMMEDIATE CONTACT REACTIONS

In a search for vehicles that might enhance the sensitivity of human s kin tests for nonimmunological immediate contact reactions, benzoic ac id was tested in 17 liquid vehicles on 16 medical students using the o pen application test method on the upper back. The results were read v isually and the change in blood flow was measured using a laser-Dopple r flowmeter 20, 40 and 60 min after application of the test substances . 2-propyl alcohol (isopropanol), ethyl alcohol (ethanol), 1,2-propyle ne glycol and water were mixed to form alcohol, alcohol/water, alcohol /alcohol, alcohol/propylene glycol and propylene glycol/water vehicles . The reactions were stronger in the alcohol/water vehicles than in th e alcohols as such. The addition of 25% propylene glycol to isopropano l and ethanol had the greatest enhancing effect on the reactions. Etha nol has been the most popular liquid vehicle in tests for non-immunolo gical immediate contact reactions, but at least with benzoic acid, str onger reactions can be elicited if alcohol/propylene glycol or alcohol /water mixture ares used.