RAST-specific IgE to egg and milk in Nigerian asthmatic patients

Food allergens have been described in studies in southern parts of Nigeria but rarely in northern parts of Nigeria. Furthermore, the role of specific antibody to such allergen moieties have not been determined. The aim of this study is to assess the role of two common food items in the aetiology of asthma in Zaria. RAST-specific IgE to milk and egg, which are two common foods in Nigeria, and skin prick tests were therefore studied in bronchial asthma patients and controls in Ahmadu Bello University Teaching Hospital, Zaria to determine their significance in the clinical manifestation of asthma patients. Total serum IgA, IgE and secretory IgA were also measured in patients and controls. RAST titres were poorly discriminating between controls and patients, although six patients had history of gastrointestinal symptoms after ingestion of egg while three patients had history of such symptoms, some with positive skin prick tests and high RAST-specific IgE titres. Asthmatic patients had significantly higher mean serum secretory IgA and total IgA levels than controls while total serum IgE levels were similarly distributed among patients and controls. It is suggested that provocation tests are mandatory to confirm bronchial allergic reactions to egg and milk and perhaps other food allergens in Nigerians in view of the non-discriminant RAST titres obtained in this study.