Aspirin and other nonsteroidal anti‐inflammatory drugs (NSAIDs) are among the most common causes of adverse drug reactions. Majority of them are of the hypersensitivity type. The two frequent clinical presentations of aspirin hypersensitivity are: aspirin‐induced bronchial asthma/rhinosinusitis (AIA/R) and aspirin‐induced urticaria/angioedema (AIU). The decisive diagnosis is based on provocation tests with aspirin, as the in vitro test does not hold diagnostic value as yet. Detailed protocols of oral, bronchial and nasal aspirin provocation tests are presented. Indications, contraindications for the tests, the rules of drug withdrawal and equipment are reviewed. Patient supervision and interpretations of the tests are proposed.

CIU with aspirin sensitivity is characterized by the eicosanoid alterations, which are similar to those present in aspirin-induced asthma.

Our findings of genotype-related differences in IgE levels in allergic patients suggest an impact of -344 C>T but not -95 T>C gene polymorphism of FcepsilonRIalpha on total levels of IgE. The genetic variability in FcepsilonRIalpha at the -344 nucleotide of its regulatory sequence, though not related to atopy, predicts higher levels of the immunoglobulin.

Background: Nonsteroidal anti-inflammatory drugs (NSAIDs) exacerbate various forms of urticaria by a nonallergic mechanism involving inhibition of cyclooxygenases.Objectives: To assess safety of cyclooxygenase inhibitors in patients with chronic idiopathic urticaria (CIU) and NSAID sensitivity and to evaluate a role of cysteinyl leukotriene metabolism and mast cell activation in sensitivity to NSAIDs in CIU.Design: Aspirin challenge test followed by randomized, prospective, double-blind, placebo-controlled crossover trial with cyclooxygenase 2 inhibitors.Setting: Tertiary referral center of a university hospital.Patients: Thirty-six patients with CIU.Interventions: Aspirin challenge test (up to 500 mg); randomized trial with rofecoxib (up to 37.5 mg) and celecoxib (up to 300 mg) in aspirin-sensitive patients. After completion of the trial, 7 patients received naproxen sodium (500 mg) as a positive control.Main Outcome Measures: Standardized skin examination, skin biopsy with mast cell count, urinary levels of leukotriene E 4 (LTE 4 ), and serum levels of mast cell tryptase.

Aspirin hypersensitivity manifesting as urticaria/angioedema remains present after 4 years in about two thirds of patients. Aspirin-precipitated skin reactions associate with increased excretion of LTE(4) and PGD(2).