Skin tests in Nigerian asthmatics from the equatorial forest zone in Benin, Nigeria.

Forty-two patients with bronchial asthma from the Benin area and 32 control subjects were subjected to skin prick tests for groups of allergens. There was a significant excess of reactions of 5 mm or over to Dermatophagoides farinae amongst the asthmatics. This was the most commonly detected allergen. There was an overall excess in asthmatics of positive reactions of over 5 mm in the other groups although there was no significant excess in any single group. There was no significant difference in the weaker skin reactions (less than 5 mm between) asthmatics and controls. From clinical histories most precipitating factors known to patients were probably non-allergic in origin, exercise, irritant odours, dust and climatic changes being the commonest. Sets of allergens specially prepared for West Africa would be valuable for skin testing asthmatics in this environment.