The diagnostic difficulty of childhood asthma leads to widespread under-diagnosis, which negatively affects the quality of life of asthmatic children. The presence of atopy in children is often used as a clinical tool to assist in making the diagnosis. However, local studies have demonstrated that atopy occurs in fewer asthmatic children than previously thought. This brings into question the association between allergy and asthma. The purpose of this study was to determine if a family history of allergy is predictive of atopic asthma in children, by comparing allergy, history of asthma and allergic symptoms, in mothers of atopic versus non-atopic asthmatic children.
Methods:
A random sample of children and their mothers attending the Children’s Chest and Allergy Clinic at Steve Biko Academic Hospital were enrolled. Skin-prick testing or radioallergosorbent test results, of the children were obtained from the child’s hospital records.
Mothers completed a detailed questionnaire which included demographic details, a history of symptoms suggestive of ‘atopy’ and allergic diseases and a history of asthma. Skin prick testing was performed on the mothers.
Results:
100 children and their parents were enrolled. 64 mothers to atopic children were used as the study group and 36 mothers to non-atopic children were used as the control group. Of the 48 mothers with a positive skin prick test, 30 (64%) had atopic children (p=0.836). Of the 16 mothers with asthma, 14 (88%) had atopic children (p=0.045). Of the 70 mothers with a history of symptoms suggestive of an allergic disease, 45 (64%) had children with atopic asthma (p=1.0). Of the 77 mothers who were considered to be allergic, 50 (65%) had children with atopic asthma (p=0.806).
Conclusions:
Both maternal skin prick positivity and a history of symptoms suggestive of allergic disease, are poor predictors of atopic asthma in children. This is true even in the mothers were considered to be allergic. However maternal asthma is a specific predictor of childhood atopic asthma with a good positive predictive and a high odds ratio. Further studies need to be conducted to compare the epidemiology of allergic asthma in different population groups.