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The number of studies examining the influence of allergies on the natural history of asthma in adults is relatively few. Most of these patients are thought to have intrinsic asthma and, therefore, allergy evaluation is not performed as a routine investigation. However, recent studies have provided some evidence that allergy may play a role in adults with asthma. It has been shown that the frequency of immediate skin test reactivity in these patients was high, ranging from 58% to 80%.1,2 A recent study by Lin et al. demonstrated that 48.1% of adult asthmatic patients have immediate skin test reactivity to at least one of the 25 common allergens tested.3 On the other hand, Inouye et al. showed that the intensity of skin test reactivity in adults was not associated with increased severity of asthma. 4 However, Pollart et al. have demonstrated that the presence of specific IgE antibodies to allergens was an important risk factor for acute asthma in adults.5 Many other reports have also shown a correlation of atopic status with asthma severity in young adults. 6-11The aim of this study was to determine the frequency of sensitization to inhalant and food allergens in adult asthmatic patients with a history of allergy in Riyadh. Such information has never been reported before in this region. The types of allergens to which the patients reacted and the optimal number that can be used as a screening panel for allergy evaluation were presented and discussed. Patients and MethodsThe study group included 100 consecutive adult asthmatic patients referred to the Allergy Clinic at King Khalid University Hospital for evaluation of possible allergic factors. Since not all the patients with asthma in the hospital have allergy evaluation routinely, this referral was based on a suggestive medical history. This included patients who suspect an association between exposure to certain provoking factors or ingestion of certain foods and precipitation or aggravation of their symptoms. Their ages ranged between 19 to 65 years and the male to female ratio was 2:1. The diagnosis of asthma was based on a compatible clinical history and the presence of variable airflow obstruction as demonstrated by an improvement in FEV1 of greater than 15% after bronchodilator. CAP RAST AssayBlood samples were obtained from the patients and the serum separated and stored at -70°C until assayed. The samples were tested for the presence of specific IgE antibodies to inhalant and food allergens by the new Pharmacia CAP System RAST FEIA (Uppsala, Sweden), which has already been shown to be very sensitive. The panel of inhalant and food allergens included in the test appear in Tables 1 and 2. The patient's serum was added to the allergen of interest, which was covalently coupled to immunoCAP. After washing away nonspecific IgE, enzymelabelled antibodies against IgE were added to form a complex. After incubation, unbound enzyme anti-IgE was washed away and the bound complex was then incubated with a developing agent. After stopping the reaction, the fluorescence...

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