Allergy symptoms depend on the substance involved and can involve the airways, sinuses and nasal passages, skin, and digestive system. Allergic reactions can range from mild to severe. In some severe cases, allergies can trigger a life-threatening reaction known as anaphylaxis.
Hay fever, also called allergic rhinitis, may cause:
- Itching of the nose, eyes or roof of the mouth
- Runny, stuffy nose
- Watery, red or swollen eyes (conjunctivitis)
A food allergy may cause:
- Tingling mouth
- Swelling of the lips, tongue, face or throat
An insect sting allergy may cause:
- A large area of swelling (edema) at the sting site
- Itching or hives all over your body
- Cough, chest tightness, wheezing or shortness of breath
A drug allergy may cause:
- Itchy skin
- Facial swelling
Atopic dermatitis, an allergic skin condition also called eczema, may cause skin to:
Some types of allergies, including allergies to foods and insect stings, have the potential to trigger a severe reaction known as anaphylaxis. A life-threatening medical emergency, this reaction can cause you to go into shock. Signs and symptoms of anaphylaxis include:
- Loss of consciousness
- A drop in blood pressure
- Severe shortness of breath
- Skin rash
- A rapid, weak pulse
- Nausea and vomiting
When to see a doctor
You might see a doctor if you have symptoms you think may be caused by an allergy, especially if you notice something that seems to trigger your allergies. If you have symptoms after starting a new medication, call the doctor who prescribed it right away.
For a severe allergic reaction (anaphylaxis), call 911 or your local emergency number or seek emergency medical help. If you carry an epinephrine auto-injector (such as EpiPen, Auvi-Q, others), give yourself a shot right away.
Even if symptoms improve after an epinephrine injection, a visit to the emergency department is still necessary to make sure symptoms don't return when the effects of the injection wear off.
If you've had a severe allergy attack or any signs and symptoms of anaphylaxis in the past, make an appointment to see your doctor. Evaluation, diagnosis and long-term management of anaphylaxis are complicated, so you'll probably need to see a doctor who specializes in allergies and immunology.