Types of Allergies
There are many types of allergies. Some allergies are seasonal, and others are year-round. Some allergies may be life-long.
Food Allergies and Their Symptoms
Food allergies are immune system responses that occur after eating certain foods. Allergic reactions to foods can be mild to severe and usually develop anywhere between a few minutes to a few hours after eating the food that triggers symptoms.
Common signs and symptoms of food allergies include:
- Swelling of the face, lips, tongue, and throat
- Itching or tingling sensation in the mouth
- Hives or eczema (itchy inflammation of the skin)
- Difficulty breathing
- Nasal congestion (stuffy nose)
- Nausea and vomiting
- Abdominal pain
- Dizziness or fainting
Any food can trigger an allergic reaction. However, some foods are more likely to cause allergies than others. Foods that commonly trigger allergies include:
- Nuts including peanuts, pecans, and walnuts
- Fish, particularly shellfish such as lobster, shrimp, and crab
- Cow’s milk
Seasonal Allergies and Their Symptoms
Seasonal allergies, also known as hay fever, are allergies that occur only during a particular season. An estimated 7.8% of adults in the U.S. suffer from seasonal allergies, usually triggered by pollen. Seasonal allergies will go away after the offending allergen no longer remains in the air.
Common signs and symptoms of seasonal allergies include:
- Watery and itchy eyes
- Itchy throat or ears
- Itchy sinuses
- Runny or stuffy nose
- Postnasal drip (when mucus runs down the back of the nose to the throat to cause coughing and congestion)
- Wheezing or shortness of breath
Skin Allergies and Their Symptoms
Skin allergies occur when the immune system overreacts to a harmless substance that comes into contact with the skin. Soaps, laundry detergent, wool, and stainless steel are some of the many allergens that can cause skin allergies.
There are three main types of skin allergies: eczema, hives, and contact dermatitis.
Eczema, also known as atopic dermatitis, is an itchy inflammation of the skin that causes a rash—particularly on the arms and back of the knees. Aside from causing itching and rash, eczema may cause redness, dryness, bumps, flaking, and peeling.
Hives, also known as urticaria, are raised, bumpy rashes that vary in shape and size. These rashes are red or skin-colored and can develop anywhere on the body. Itching is the main symptom of hives.
Contact dermatitis is a rash that develops immediately after the skin comes into contact with the allergen. The rash produced by this skin allergy is highly similar in appearance to the rash caused by eczema. Still, it occurs only in the spot that came into contact with the offending substance. The areas most commonly affected by contact dermatitis are the face, hands, neck, and feet.