The prevalence of childhood asthma is increasing. Sensitization to aeroallergens is a major risk factor for asthma. Indoor aeroallergens are one of the risk factors for the development and severity of mild-to-moderate asthma in children. Similarly, a significant association was found between asthma and the presence of food-specific IgE antibodies in young children. Children with food allergy frequently have increased bronchial hyper-reactivity (BHR), independent of respiratory symptoms. Furthermore, asthma is an uncommon manifestation of food allergy, typically seen with other food-induced symptoms.
This study included asthmatic children (n=659) attended the pediatric asthma and allergy clinic at Khorfakkan Hospital (Sharjah, United Arab Emirates). Skin prick test (SPT) was done for 103 children with evidence of frequent exacerbation of asthma symptoms or refractory asthma. The SPT included a series of inhaler (by Stallergens®) and food (fresh fruits or vegetables) allergens. Antihistamines were stopped at least 2 weeks before SPT. Forty-three (68%) of 103 patients were males.
Sixty-three (61%) children were positive to at least one allergen. No gender difference noticed. The highest rate of a positive test was between 5 and 12 years of age (43%), followed by 2 to 5 years of age (30%). This trend was the same in both genders. Nineteen children (30%) were positive to 3 allergens, 15 (24%) were positive to 2 allergens and 11 (18%) were positive to 1 allergen. The most common indoor aeroallergens were house dust mites (Der f 16%, Der p 14%), dogs (12%), and cockroaches (11%). The most common food allergens were horse chestnut (20%), sesame (14%) and cow milk (12%). Collectively, the indoor aeroallergens were twice positive as food allergens.
Aeroallergens and food allergy are important causes of asthma exacerbations in children. These potential precipitating factors should be considered in refractory asthma or in frequent exacerbations. Aeroallergens and food allergy are under-recognized risk factors for problematic asthma.