Immediate Reactions to More Than 1 NSAID Must Not Be Considered Cross-Hypersensitivity Unless Tolerance to ASA Is Verified

BACKGROUND AND OBJECTIVES

Individuals who develop drug hypersensitivity reactions (DHRs) to chemically unrelated nonsteroidal anti-inflammatory drugs (NSAIDs) are considered cross-hypersensitive. The hallmark for this classification is that the patient presents a reaction after intake of or challenge with acetylsalicylic acid (ASA). Whether patients react to 2 or more NSAIDs while tolerating ASA remains to be studied (selective reactions, SRs). Objective: To identify patients with SRs to 2 or more NSAIDs including strong COX-1 inhibitors.

METHODS

Patients who attended the Allergy Service of Hospital Infanta Leonor, Madrid, Spain with DHRs to NSAIDs between January 2011 and December 2014 were evaluated. Those with 2 or more immediate reactions occurring in less than 1 hour after intake were included. After confirming tolerance to ASA, the selectivity of the response to 2 or more NSAIDs was demonstrated by in vivo and/or in vitro testing or by controlled administration.

RESULTS

From a total of 203 patients with immediate DHRs to NSAIDs, 16 (7.9%) met the inclusion criteria. The patients presented a total of 68 anaphylactic or cutaneous reactions (mean [SD], 4.2 [2.1]). Most reactions were to ibuprofen and other arylpropionic acid derivatives and to metamizole. Two different NSAIDs were involved in 11 patients and 3 in 5 patients.

CONCLUSIONS

Patients with NSAID-induced anaphylaxis or urticaria/angioedema should not be considered cross-hypersensitive unless tolerance to ASA is verified.

Immediate hypersensitivity reactions to ibuprofen and other arylpropionic acid derivatives

BACKGROUND

Although ibuprofen and other arylpropionic acid derivatives (APs) are the most common medicines involved in hypersensitivity drug reactions (HDRs) to NSAIDs, no patient series studies have been performed regarding immediate selective reactions (SRs) to these drugs.

OBJECTIVE

To characterize patients with immediate selective HDRs to ibuprofen and other APs through clinical history and challenge.

METHODS

Subjects who developed an HDR to APs less than 1 h after drug intake were included. Tolerance to aspirin was assessed and challenge was performed with ibuprofen in all cases, and additionally with the culprit drug (if different) in those patients that tolerated ibuprofen. Serum tryptase levels and tryptase immunohistochemical staining in skin biopsies were also assessed in some patients with a positive DPT to ibuprofen.

RESULTS

From a total of 245 patients with a confirmed history of HDRs to APs, 17% were classified as selective immediate hypersensitivity reactors by both clinical history and challenge. A selective response to naproxen and dexketoprofen with tolerance to ibuprofen was found in 16 of 20 cases. Significant differences in serum tryptase levels were observed between 2 and 24 h in the 11 cases that were studied further.

CONCLUSIONS

Within the group of patients with HDRs to NSAIDs, APs can induce immediate SRs. Within this group, selective responses to a single drug or responders to several APs may exist, suggesting potential immunological cross-reactivity.

Hypersensitivity Reactions to Nonsteroidal Anti-inflammatory Drugs in Children and Adolescents: Selective Reactions

Nonsteroidal anti-inflammatory drugs (NSAIDs) are used throughout the world to treat pain and inflammation; however, they can trigger several types of drug hypersensitivity reactions (DHRs) in all age groups. Although most such reactions occur through activation of the leukotriene pathway without specific immunological recognition (cross-intolerance), a significant number of DHRs to NSAIDs are due to immunological mechanisms (selective reactions [SRs]). SRs are thought to be induced by specific IgE antibodies or by T cells. In this manuscript, we focus on SRs, which are of great concern in children and adolescents and comprise a heterogeneous set of clinical pictures ranging from mild entities such as urticaria/angioedema to potentially life-threatening conditions such as Stevens-Johnson syndrome/toxic epidermal necrolysis. Paracetamol and ibuprofen are the most frequent elicitors of IgE-mediated SRs, although pyrazolones have also been implicated. T cell-mediated reactions are infrequent in children but have been associated with ibuprofen, naproxen, and dipyrone. In this review, we analyze the available literature on SRs in children and adolescents, with emphasis on epidemiological data, mechanisms, and drugs involved, as well as on diagnostic procedures.