Allergy Symptoms and Diagnosis

When an allergic person is exposed to an allergen they are sensitive to, the body releases chemicals that cause any one or all of these familiar allergy symptoms:

  • Nasal symptoms: itchy, runny nose; sneezing; coughing

  • Eye symptoms: itchy, watery eyes, redness

  • Skin symptoms: itchy, sensitive skin; rash or hives; swelling

  • Respiratory symptoms: shortness of breath, cough, wheeze, chest tightness

Occasionally, an allergic reaction can turn deadly. Anaphylaxis is a life-threatening allergic reaction that affects two or more parts of the body at once, including your skin, mouth, stomach, lungs or heart. Often it occurs as a series of reactions. For instance, skin-related symptoms such as hives and swelling may appear first, followed by breathing problems or other internal symptoms. But anaphylaxis can also occur without any skin symptoms at all.

Diagnosing Allergies 

It’s important to know exactly what you’re allergic to, so you can take steps to reduce your symptoms, whether through avoidance, medicine or other treatments, including allergen immunotherapy (allergy shots).

If your allergies are disrupting your sleep or daily activities, making you miss school or work, or affecting your asthma or eczema, then it’s time to see a board-certified allergist for an accurate diagnosis.

Don’t be fooled by deceptive third-party allergy testing and immunotherapy being offered by allergy technicians in some primary care practices. Insist on seeing a doctor who is properly trained, experienced and skilled at allergy diagnosis and care.

Testing alone isn’t enough. Like a good detective, a board-certified allergist will put all the evidence together before coming up with a diagnosis. Things the allergist will consider:

  • Family history of allergies and allergic diseases, such as asthma or eczema

  • Personal history of allergy symptoms

  • Personal health history

  • Home and work environments, hobbies and activities that might expose you to allergens or irritants

  • Physical exam of eyes, ears, nose, lungs, heart

  • Allergy skin or blood tests 

Allergy Tests

There are three types of tests commonly used to detect allergies:

  • Skin tests – droplets of suspected allergens are placed on or just under the skin surface; raised bumps (about the size of a mosquito bite) strongly indicate a reaction or allergy to that allergen

  • Blood tests – lab tests detect antibody reaction to specific allergens

  • IgE tests – a blood test that detects how much IgE (the antibody related to allergies) is in your blood; does not identify specific allergens

Allergy tests are very accurate in showing an immune response to particular allergens but cannot determine for sure which are actually responsible for your symptoms. In some cases, people may have a positive skin or blood test reaction to a particular allergen, but do not experience symptoms when exposed to it in daily life.

When It’s Not Really An Allergy

In some cases, allergy-like symptoms are caused by irritants, rather than allergens. That means that it’s not a classic allergic response, won’t respond to traditional allergy treatments and can’t be detected by skin or IgE blood tests. Common inhaled irritants include:

  • Smoke, whether inhaled directly or secondhand from a burning tobacco product, or from wood burning stoves or wildfires

  • Perfume, including air fresheners and scented candles

  • VOCs (volatile organic compounds) emitted by some furnishings and building materials

  • Air pollution

Controlling allergies can be a complex process, which is why tests should be conducted and interpreted by a board-certified allergist.