Atopy is a risk factor for non-steroidal anti-inflammatory drug sensitivity

Background: There is scarce information in the literature about a possible association between atopy and certain clinical manifestations of NSAID sensitivity. Objectives: (1) To evaluate the prevalence of atopy in patients proved to be sensitive to cyclooxygenase inhibitors. (2) To assess cross-reactivity to two alternative NSAIDs, paracetamol (acetaminophen) and nimesulide. Methods: NSAID-sensitive patients attending an allergy clinic and unselected controls were prick tested with inhalant allergens. Oral challenges with NSAIDs were carried out by the single-blinded (SBOC) method. Clinical data about personal and family history of allergic and atopic diseases were obtained by a careful review of the medical records and by direct questioning by experienced allergists. Results: Fifty patients had positive SBOCs to the suspected NSAID and only these were studied. A personal history of atopic diseases was present in 41 patients (82%) and 7 controls (14.5%), and a family history in 24 patients (48%) and 6 controls (12.5%). Prick skin tests with aeroallergens were positive in 39 of 45 patients tested (86.6%) and in 14 of 48 controls (29.1%), (P = .0001). Skin test positivity rates were higher in patients with cutaneous challenge reactions who responded to only one NSAID (single reactors) in comparison to cross-reactors (P = .04). The most frequent clinical manifestations of NSAID sensitivity were (I) cutaneous (angioedema, urticaria) in 34 patients, (2) blended (cutaneous plus respiratory) in 12, (3) respiratory in 3, and (4) anaphylactoid in 1. Aspirin, pyrazolone, paracetamol, and ibuprofen were the drugs more frequently implicated in these reactions. Cross-sensitivity with paracetamol and nimesulide were 32% and 25%, respectively. Conclusions: The prevalence of atopy is increased in challenge-proven NSAID-intolerant patients. The atopic condition may represent an important risk factor for developing reactions to these drugs. Paracetamol and nimesulide are relatively safe alternative choices in those patients, although their use still carries some risk of unwanted reactions.