Bencard skin test in chronic urticaria

ABSTRACT

Bencard pitch skin tests with different allergens were performed on 127 patients with chronic urticaria. 100 [78.7%] patients were reactive while 27 [21.3%] patients were non reactive. No significant correlation was found between prick skin test results and either the age or the sex of the patients. Highest percentages of positivity were found with inhalant allergens e.g. house dust [44/127 i.e. 34.6%]; house dust mite [30/127 i.e. 23.6%] and feathers [26/124 i.e. 20.4%]. Atopy however, does not seem to play an important role in chronic urticaria. Prick tests with food allergens showed positive reactions in 15.7% [20/127] of patients. Most of the patients with penicillin allergy were recommended to be on a diet free from milk and milk products. In 50% this was successful. The value of these findings is discussed. Desensitization was performed for 47 patients. 21 [44.7%] only reported improvement. The frequent recurrence and the life long treatment limit its value. Desensitization is thus recommended in the routine treatment of chronic urticaria