From the Guidelines
Approximately 7% of adults with asthma and one-third of patients with asthma and nasal polyposis have NSAID-exacerbated respiratory disease (AERD), which is the most relevant condition related to NSAID allergies. This prevalence is based on the most recent and highest quality study available, which was published in 2022 1. The general population has a lower prevalence of NSAID allergies, but the exact percentage is not well-established. However, it is estimated to be around 1-2% based on previous studies.
Key Points to Consider
- NSAID allergies can manifest as respiratory reactions (bronchospasm, rhinitis), cutaneous reactions (urticaria, angioedema), or rarely as severe anaphylaxis.
- The most common mechanism isn't a true allergy but rather a non-immunological reaction where NSAIDs inhibit the COX-1 enzyme, shifting arachidonic acid metabolism toward the lipoxygenase pathway and increasing production of leukotrienes, which trigger symptoms.
- People with NSAID sensitivity often react to multiple NSAIDs with similar chemical structures.
- Those with confirmed NSAID allergies should consider alternative pain relievers like acetaminophen (paracetamol) or, in some cases, selective COX-2 inhibitors like celecoxib, which may be tolerated by some NSAID-sensitive individuals.
- Anyone experiencing symptoms after taking NSAIDs should seek medical evaluation before taking these medications again, as recommended by the 2022 practice parameter update on drug allergy 1.
Management and Diagnosis
- A challenge procedure or desensitization protocol may be used to diagnose and manage AERD, depending on the clinical scenario and the intention to place the patient on a daily therapeutic aspirin dose 1.
- The diagnosis of AERD poses a clinical dilemma in persons who would benefit from aspirin or other NSAID therapy, and a controlled aspirin challenge may be necessary to confirm the diagnosis 1.
From the Research
Prevalence of NSAID Allergies
- The exact percentage of the population with allergies to NSAIDs is not specified in the provided studies 2, 3, 4, 5, 6.
- However, it is mentioned that NSAIDs are the leading cause of hypersensitivity drug reactions 2, 3, 5, 6.
- The studies suggest that the prevalence of NSAID-induced hypersensitivity reactions is increasing, with a wide range of adverse effects, from mild local skin rashes to severe, generalized symptoms and even life-threatening anaphylaxis 2, 3, 4, 5, 6.
Types of NSAID Allergies
- The studies classify NSAID-induced hypersensitivity reactions into different types, including:
- Cross-hypersensitivity reactions (CRs), associated with COX-1 inhibition 6.
- Selective reactions, associated with immunological mechanisms 6.
- NSAIDs-exacerbated respiratory disease, NSAIDs-exacerbated cutaneous disease, and NSAIDs-induced urticaria/angioedema 6.
- Single-NSAID-induced urticaria/angioedema/anaphylaxis and single-NSAID-induced delayed reactions 6.
Diagnosis of NSAID Allergies
- The diagnosis of NSAID-induced hypersensitivity reactions is often based on a clear clinical history and controlled administration of the drug to assess tolerance 4, 5.
- In vivo diagnostic tests, such as skin testing, may be useful in some cases, but their sensitivity is often low 5.
- There are no reliably validated in vitro tests available for the diagnosis of NSAID-induced hypersensitivity reactions 4, 5, 6.