Allergy to Nonsteroidal Anti-Inflammatory Drugs (NSAID’s)

Nonsteroidal anti-inflammatory drugs (NSAID’s) are a group of medications related to aspirin.  The group includes commonly used drugs such as ibuprofen (i.e., Motrin, Advil), naproxen (i.e., Aleve, Naprosyn), diclofenac (i.e., Voltaren), etodolac, (i.e., Lodine), among others.  These agents are widely used in order to reduce inflammation (e.g., decrease pain and reduce swelling of joints in various forms of arthritis).  They also help reduce fever caused by infections as well as relieve discomfort after injuries.

NSAID’s act by blocking an enzyme called cyclooxygenase-1 (COX-1).  Cyclooxygenase-1 acts by producing compounds known as prostaglandins.  These prostaglandins are involved in tissue inflammation which results in pain, swelling, and/or fever.  Since NSAID’s block the enzyme cyclooxygenase-1, they also inhibit the production of prostaglandins.  Thus, NSAID’s will decrease tissue inflammation and reduce pain, swelling, and fever.  Aspirin not only blocks the enzyme cyclooxygenase-1, but it also blocks the cyclooxygenase-2 COX-2) enzyme as well.  Thus, aspirin also leads to a decrease in tissue inflammation as well as a reduction in pain, swelling, and fever.  In addition, aspirin decreases the activity of blood components known as platelets.  While platelets are known to promote the clotting of blood, aspirin, on the other hand, helps prevent blood clots due to its antagonistic effect on platelets, which reduces the risk of heart attacks and strokes.

Common side effects of aspirin may include bruising and abdominal pain.  Less commonly, a stomach ulcer or stomach bleeding may occur.  Very high doses of aspirin may cause confusion or ringing in the ears (i.e., tinnitus).

Aspirin can cause allergic reactions in some individuals.  These symptoms may include flushing, generalized itching (i.e., pruritus), hives (i.e., urticaria), swelling (i.e., angioedema), nasal congestion, runny nose, and/or asthma usually within an hour of taking a tablet.  These reactions occur in approximately 1% of people receiving aspirin.  It should be pointed out that in patients with hives, nasal polyps and asthma, the risk could be as high as 30%.  The co-existence of asthma, nasal polyps, and aspirin sensitivity is termed Samter’s triad or aspirin exacerbated respiratory disease (AERD).

The manifestations of aspirin and NSAID sensitivity may include:

  • Itching, usually generalized
  • Hives
  • Swelling of soft tissues such as eyelids, lips, tongue, throat, etc.
  • Chest tightness, wheezing, coughing, shortness of breath
  • Dizziness and altered sensorium


The diagnosis of NSAID allergy is based mostly on the history of adverse effects within a short time after receiving the drug.  There is no reliable blood or skin allergy test for confirming or excluding the sensitivity to aspirin and NSAID’s.  The only way to assess aspirin sensitivity is by a graded open challenge under strict medical supervision.  Challenge testing is not always necessary, but may be advised in some circumstances in order to prove that sensitivity exists, or to prove the safety of an unrelated medication.


The treatment of NSAID allergy is directed at the relief of symptoms with antihistamines, bronchodilators, and epinephrine in cases of anaphylaxis.


Preventing NSAID reactions involves the total avoidance of aspirin and all cross- reacting NSAID’s.  As there are so many brand names of the same medication, and so many types of medications available, accidental exposure to aspirin or NSAID’s may occur.  NSAID’s are common ingredients of many over-the-counter painkillers and cold/flu remedies.

If you have ongoing hives, you should avoid aspirin and NSAID’s unless you know that you can tolerate them without a problem.  If you are already taking regular aspirin (for example, to prevent heart attack or stroke), or a regular arthritis tablet for the treatment of pain, then you should consult with your primary care physician, rheumatologist, or cardiologist about stopping the aspirin.  Your physician may tell you that you do not need to stop taking the aspirin unless your hives clearly get much worse after taking the medicine.  If you have had an allergic reaction to one type of NSAID, a challenge with a different drug can be considered if you need to take aspirin or an anti-inflammatory medication for the treatment of arthritis.

Some NSAID’s such as celecoxib (i.e., Celebrex) and meloxicam (i.e., Mobic) predominantly inhibit the cyclooxygenase-2 (COX-2) enzyme rather than the cyclooxygenase-1 (COX-1) enzyme.  Thus, they can be taken safely by many patients (but not all), who have aspirin and NSAID sensitivity.  Acetaminophen (i.e., Tylenol) and codeine do not usually cross-react with NSAID’s and can usually be taken safely for the relief of fever and/or pain.

Aspirin desensitization is a procedure that could be helpful in some patients with AERD to improve asthma control, inhibit nasal polyp growth, and to enable aspirin therapy for reducing the risk of blood clots in order to protect the heart and the brain.

The allergy specialists at Black & Kletz Allergy see both adult and pediatric patients and have over 5 decades of experience in the field of allergy, asthma, and immunology.  If you have or suspect you have a sensitivity or allergy to aspirin, NSAID, or any other medication, please call our office.  Black & Kletz Allergy has 3 convenient locations with on-site parking located in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA.  The Washington, DC and McLean, VA offices are Metro accessible and we offer a free shuttle that runs between the McLean, VA office and the Spring Hill metro station on the silver line.  To schedule an appointment, please call any of our offices or you may click Request an Appointment and we will respond within 24 hours by the next business day.  We have been servicing the greater Washington, DC metropolitan area for over 50 years and we look forward to providing you with the highest state-of-the-art allergy care in a welcoming and relaxed environment.