NSAID‐induced urticaria/angioedema does not evolve into chronic urticaria: a 12‐year follow‐up study

Background Nonsteroidal anti‐inflammatory drugs (NSAIDs) are the most frequent medicaments involved in drug hypersensitivity reactions, with NSAID‐induced urticaria/angioedema (NIUA) being the most frequent clinical entity. The natural evolution of NIUA has been suggested to lead to chronic urticaria (CU) in an important proportion of patients, such that NIUA may therefore precede CU. Our aim was to verify whether these entities are related by following up a large cohort of patients with NIUA as well as a control group over a long period of time. Methods The study comprised three groups: (i) patients with a confirmed history of NIUA (more than two episodes with at least two different NSAIDs or positive drug provocation tests), (ii) patients with more than two episodes of urticaria/angioedema to a single NSAID with good tolerance to a strong COX‐1 inhibitor and/or evidence by in vivo tests supporting specific IgE antibodies to the drug (single NSAID‐induced urticaria/angioedema, SNIUA), and (iii) controls who tolerated NSAIDs. All cases in the three groups were followed up over a period of 12 years. Results There were 190 patients with NIUA (64.6% female; mean age 43.71 ± 15.82 years, 110 with SNIUA, and 152 controls. At the 12‐year evaluation, 12 patients with NIUA (6.15%) had developed CU over a 1‐ to 8‐year period. Similar proportions were seen in SNIUA and controls. Conclusions Nonsteroidal anti‐inflammatory drugs‐induced urticaria/angioedema does not seem to precede the onset of CU over the medium term. Further research including a longer follow‐up is necessary to verify this observation.