Peanut allergy: The frequency of sensitization to peanut allergen in patients with allergic disease

Objectives: Peanut allergy is the most frequent cause of fatal and near-fatal food-induced anaphylaxis. The frequency of sensitization to peanut allergen, among Saudi patients with allergic disease, was determined. The objective is to draw attention to this life-threatening food allergy and discuss some clinical and diagnostic aspects. Methods: One hundred and eighty-eight subjects were included in the study. They comprised 67 adult asthmatics, 32 asthmatic children, 42 adults with chronic urticaria and 47 adults with allergic rhinitis. All the patients were referred to the Allergy Clinic at King Khalid University Hospital for evaluation of possible allergic factors. Specific IgE antibodies to peanut, in addition to other inhalant and food allergens, were determined by the Pharmacia CAP radioallergosorbent, fluoroimmunoassay test. Results: Thirty-eight patients (20%) of the study group showed a positive CAP radioallergosorbent reaction to peanut allergen. This included all grades of reactions from Class 1 to Class 4. Of these, 12 patients (6%) gave a Class 3 reaction and above. Class 3 reactions were shown to be the cut-off values predictive of clinical sensitivity. Class 3 reactions were more frequently noted among adults and children with asthma. Conclusion: It appears that 20% of Saudi patients, with allergic disease, are sensitized to peanut allergens. Clinical sensitivity, as predicted by Class 3 reactions, was found in 6% of the patients. Since peanut allergy persists indefinitely in affected patients and severity increases with age, sensitized patients need advice on preventive measures and regular follow-up. Patients with clinical sensitivity need training on the use of rescue medications particularly parents of affected children.