This article reviews a study which included 40 patients from the allergy out-patient clinic and compared the reactions caused by three drugs in the dermal inhibition of histamine. All patients received subcutaneous histamine and were checked on different days. The size of the papule was compared before and after treatment. The reactions seen on day 20 were recorded and used for arriving at final conclusions. Astemizole showed better results than loratadine and terfenadine. Loratadine was seen to work better than terfenadine and the latter, better than the control group.