Symptoms:

Symptoms that occur shortly after you come into contact with the substance you are allergic to may include:

• Itchy nose, mouth, eyes, throat, skin, or any area
• Problems with smell
• Runny nose
• Sneezing
• Tearing eyes

Symptoms that may develop later include:

• Stuffy nose (nasal congestion)
• Coughing
• Clogged ears and decreased sense of smell
• Sore throat
• Dark circles under the eyes
• Puffiness under the eyes
• Fatigue and irritability
• Headache
• Memory problems and slowed thinking

Signs and tests:

The health care provider will perform a physical exam and ask you questions about your symptoms. Your history of symptoms is important in diagnosing allergic rhinitis, including whether the symptoms vary according to time of day or the season, exposure to pets or other allergens, and diet changes.

Allergy testing may reveal the specific substances that trigger your symptoms. Skin testing is the most common method of allergy testing. See the article on allergy testing for detailed information.

If your doctor determines you cannot undergo skin testing, special blood tests may help with the diagnosis. These tests can measure the levels of specific allergy-related substances, especially one called immunoglobulin E (IgE).

A complete blood count (CBC), specifically the eosinophil white blood cell count, may also help reveal allergies.