The diagnosis of fragrance allergies begins with a physical examination. The physician will ask questions to determine the origin of the condition. The patient's medical history will be reviewed and pre-existing medical conditions identified.

An allergy skin test may be performed to identify the specific chemical(s) causing the reaction. A skin test is a fast, simple test that involves placing a substance on or just under the skin to provoke a reaction. The test is positive when the skin reddens and swells.

It may be difficult to diagnose the specific chemical or chemical compound to which an individual is sensitive or allergic. Fragrance formulas are often trade secrets and companies guard the specific formulas to protect their intellectual property.

Because symptoms of fragrance allergies can be the same as a fragrance irritation, it can be difficult to tell these conditions apart. Often a diagnosis of fragrance irritation is made only after a fragrance allergy is ruled out as a cause of symptoms.