NSAID & Aspirin Allergy
Also known as: Ibuprofen allergy, Aspirin sensitivity, NSAID hypersensitivity
Adverse reactions to non-steroidal anti-inflammatory drugs (NSAIDs) including aspirin, ibuprofen, and naproxen affect up to 2% of the population. They range from mild hives to severe anaphylaxis, and may be immunological (true allergy) or non-immunological (intolerance).
Category
Drug Allergies
Severity
Moderate to SeverePrevalence
1–2% of the general population; higher in patients with asthma or chronic urticaria.
Symptoms
Airways & Breathing
- Nasal polyps and sinusitis (aspirin-exacerbated respiratory disease)
- Bronchospasm
- Wheezing
Skin
- Urticaria
- Angioedema
- Flushing
Digestive
- Nausea
- Stomach pain
Systemic / Other
- Anaphylaxis
- Hypotension
- Loss of consciousness
How It's Diagnosed
- Detailed clinical history — which drug, what dose, timing, and nature of the reaction
- Aspirin challenge test (graded oral provocation) — the definitive test
- Skin tests (limited value for most NSAID reactions due to non-IgE mechanism)
- Distinguishing cross-reactive (COX-1 inhibition) from single-drug reactions
Avoidance Strategies
- Cross-reactive NSAID intolerance: avoid all traditional NSAIDs — aspirin, ibuprofen, naproxen, diclofenac, ketoprofen
- COX-2 selective inhibitors (celecoxib) are usually tolerated in cross-reactive intolerance
- Paracetamol (acetaminophen) in normal doses is generally safe
- Declare NSAID sensitivity before any procedure or prescription
Cross-Reactivity
- Most NSAID reactions are cross-reactive (COX-1 dependent) — avoiding one NSAID often means avoiding all
- COX-2 selective inhibitors generally do not cross-react
Aspirin-exacerbated respiratory disease (AERD)
AERD (also called Samter's triad) is a distinct syndrome combining asthma, nasal polyps, and aspirin/NSAID intolerance. It affects about 10% of adult asthmatics. The underlying mechanism involves overproduction of leukotrienes when COX-1 is inhibited.
Aspirin desensitisation — a supervised protocol of gradually increasing aspirin doses — can actually improve nasal and lung symptoms in AERD patients who are good candidates.
Related Allergens
Medical disclaimer
This page is for educational purposes only. Allergy diagnosis and management must be carried out by a qualified allergist. Do not attempt to test yourself with suspected allergens. Always carry prescribed emergency medications and follow your written action plan.
Reviewed 2026-06-01 · Looms Medical Team