Allergy symptoms, which depend on the substance involved, can affect your 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, can cause: Hay fever,  Sneezing Itching of the nose, eyes or roof of the mouth Runny, stuffy nose Watery, red or swollen eyes (conjunctivitis)  A food allergy can cause: A food allergy  Tingling in the mouth Swelling of the lips, tongue, face or throat Hives Anaphylaxis  An insect sting allergy can cause: An insect sting allergy  A large area of swelling (edema) at the sting site Itching or hives all over the body Cough, chest tightness, wheezing or shortness of breath Anaphylaxis  A drug allergy can cause: A drug allergy  Hives Itchy skin Rash Facial swelling Wheezing Anaphylaxis  Atopic dermatitis, an allergic skin condition also called eczema, can cause skin to: Atopic dermatitis,  Itch Redden Flake or peel  Anaphylaxis Some types of allergies, including allergies to foods and insect stings, can trigger a severe reaction known as anaphylaxis. A life-threatening medical emergency, anaphylaxis 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 Lightheadedness A rapid, weak pulse Nausea and vomiting 
allergy symptoms  depend substance involved  can affect airways  sinuses nasal passages  skin  digestive system  allergic reactions can range mild severe  severe cases  allergies can trigger life-threatening reaction known anaphylaxis  hay fever  called allergic rhinitis  can cause: hay fever   sneezing itching nose  eyes roof mouth runny  stuffy nose watery  red swollen eyes (conjunctivitis)  food allergy can cause: food allergy  tingling mouth swelling lips  tongue  face throat hives anaphylaxis  insect sting allergy can cause: insect sting allergy  large area swelling (edema) sting site itching hives body cough  chest tightness  wheezing shortness breath anaphylaxis  drug allergy can cause: drug allergy  hives itchy skin rash facial swelling wheezing anaphylaxis  atopic dermatitis  allergic skin condition called eczema  can cause skin to: atopic dermatitis   itch redden flake peel  anaphylaxis types allergies  including allergies foods insect stings  can trigger severe reaction known anaphylaxis  life-threatening medical emergency  anaphylaxis can cause shock  signs symptoms anaphylaxis include:  loss consciousness drop blood pressure severe shortness breath skin rash lightheadedness rapid  weak pulse nausea vomiting 
allergies