Hives, also known as urticaria, are itchy, raised, reddish areas on the skin that are usually triggered by an allergen. Hives affect around 20 percent of the population at some time in their life. A few common triggers may include medications, infections, pollen, or foods.
Angioedema is swelling of the area beneath the skin or fatty tissue. The main difference between hives (urticaria) and angioedema is that hives only affect the top layer of skin. Angioedema affects the deeper layers, including the dermis, subcutaneous tissue, the mucosa, and submucosal tissues.
Symptoms
Hives are itchy welts that can occur anywhere on the body, including the face, chest, arms, and back. The welts are usually pink or red with an oval or round shape and can range from a few millimeters to several inches across.
Angioedema tends to affect a person’s hands, feet, genitals, lining of the throat, and the face. The swollen areas may feel hot and possibly painful. In some cases, bronchospasm may occur if the lining of the throat is affected, causing breathing problems.
Causes
Hives occur when the body reacts to an allergen, releasing histamine. When histamine is released, the tiny blood vessels known as capillaries leak fluid. This fluid accumulates in the skin and causes the itchy rash, known as hives. Some known triggers include:
- Medications
- Foods, such as nuts, shellfish, eggs, and wheat products
- Infections
- Pollen, dust mites, or pet dander
- Insect bites and stings
- Sunlight exposure
There are two main types of angioedema: Allergic and drug-induced.
Allergic angioedema: Allergic angioedema is the most common type of angioedema and usually affects those with an allergy, such as food, medications, venom, pollen or animal dander.
Drug-induced angioedema: Certain medications can cause angioedema, such as non-steroidal anti-inflammatory drugs (ibuprofen or aspirin) or angiotensin-converting enzyme (ACE) inhibitors (a treatment for hypertension or high blood pressure).
Treatment
Treatment for acute hives includes non-sedating antihistamines, such as cetirizine or fexofenadine. These medications help by blocking the effects of histamines and reducing the rash. At NEAAI, we offer immunobiological treatment for severe hives (Xolair).
Those who have angioedema may need to see an allergist or immunologist, as angioedema can cause potentially serious breathing difficulties.
Many allergy-related symptoms can be managed with over the counter medicines, prescription medications, and environmental avoidance strategies if the allergies are known. With allergy skin testing and/or blood testing, we can discover hidden triggers, confirm suspected triggers, and provide additional treatments, including immunotherapy if appropriate.
Contact Northeast Allergy, Asthma & Immunology today to schedule your appointment.
