Salicylate sensitivity occurs in people who experience symptoms after exposure to the chemical salicylate. Salicylates occur naturally in many plants and act as a natural preservative, preventing the plant from rotting and guarding it from bacteria and fungi. The chemical is also manufactured in the form of salicylic acid to be used as a preservative against spoilage. Salicylates are found in many foods and products, including fruit, vegetables, health and beauty products and medicine. It is probably best-known as an ingredient used in aspirin and other pain relievers.

Salicylate sensitivity causes symptoms similar to those of an allergy, but it does not involve an immunoglobulin E (IgE)-mediated response. Symptoms can be mild or can be life-threatening, as in the case of anaphylactic shock.

Sensitivity to salicylates is similar to food intolerance. A sensitive person may be able to tolerate a small amount of salicylates. However, an excessive intake of salicylates, the amount of which will vary from one individual to another, creates a cumulative effect in the body that triggers symptoms.

Salicylates can be found in two forms:

• Natural form, such as in certain fruits, vegetables, herbs and plants
  
  
• Manufactured substances, including medicines, solvents and perfume fixatives

Salicylates are found in certain medications that reduce inflammation and relieve pain, including aspirin and ibuprofen. They work by blocking the release of chemicals responsible for pain and swelling. Salicylates can also reduce fever by changing the body’s thermostat. In addition, several skin-care products and other consumer goods also contain salicylates.

People sensitive to salicylates, including aspirin, may be able to tolerate some salicylate-containing foods but not others. Sensitive people may be able to consume small amounts of some foods without triggering a reaction, or consume them in a cooked instead of raw form.

Salicylate sensitivity is more likely to occur in people who have moderate to severe asthma or chronic rhinosinusitis. The problem becomes more common as people age and as their asthma gets worse.