Allergies Getting Under Your Skin?
If you have red, bumpy, scaly, itchy, or swollen skin, is it because of a skin allergy? Here is a breakdown of the most common types of allergic skin conditions, what causes them, and how they can be treated.
Hives and Angioedema
Hives (or urticaria) are red, itchy, raised areas of the skin that can range in size and appear anywhere on your body. Most common are acute cases, where food or drug allergies are triggers. These hives usually go away within a few days. In cases of chronic hives, people may have them for months to years.
Angioedema is a swelling of the deeper layers of the skin that sometimes occurs with hives. Angioedema is usually not red or itchy. The areas often involved are the eyelids, lips, tongue, hands, and feet.
Food or drug reactions are a common cause of acute hives and angioedema. Viral or bacterial infection can also trigger hives in both adults and children. Physical urticaria is hives resulting from a nonallergic source: rubbing of the skin, cold, heat, physical exertion or exercise, pressure, and direct exposure to sunlight.
When certain substances come into contact with your skin, they may cause a rash called contact dermatitis.
If the cause of your hives can be identified, you should avoid that trigger. With acute hives, some drugs or foods may take days to leave the body, so your doctor may prescribe antihistamines to relieve your symptoms until that happens.
When certain substances come into contact with your skin, they may cause a rash called contact dermatitis. Irritant contact dermatitis is often more painful than itchy, and is caused by a substance damaging the part of your skin it comes into contact with. The longer your skin is in contact with the substance, or the stronger the substance is, the more severe your reaction will be. These reactions appear most often on the hands and are frequently work related.
Allergic contact dermatitis is best known by the itchy, red, blistered reaction experienced after you touch poison ivy. This allergic reaction is caused by a chemical in the plant called urushiol. You can have a reaction from touching other items the plant has come into contact with. However, once your skin has been washed, you cannot get another reaction from touching the rash or blisters. Allergic contact dermatitis reactions can happen 24 to 48 hours after contact. Once a reaction starts, it takes 14 to 28 days to go away, even with treatment.
Nickel, perfumes, dyes, rubber (latex) products, and cosmetics also frequently cause allergic contact dermatitis. Some ingredients in medications applied to the skin can cause a reaction, most commonly neomycin, an ingredient in antibiotic creams. For irritant contact dermatitis, you should avoid the substance causing the reaction. You should also avoid spilling chemicals on your skin. Gloves can sometimes be helpful. Since these reactions are nonallergic, avoiding the substance will relieve your symptoms and prevent lasting damage to your skin.
Treatment for allergic contact dermatitis depends on how severe the symptoms are. Cold soaks and compresses can offer relief for the acute, early, itchy, blistered stage of your rash. You may also be prescribed topical corticosteroid creams. To prevent the reaction from returning, avoid contact with the offending substance. If you and your doctor cannot determine the substance that caused the reaction, your doctor may conduct a series of patch tests to help identify it.
A common allergic reaction often affecting the face, elbows, and knees is atopic dermatitis, or eczema. This red, scaly, itchy rash is more common in young infants and those who have a personal or family history of allergy.
Common triggers include airborne allergens, such as cat dander or house dust, overheating or sweating, and contact with irritants, such as wool or soaps. In older individuals, emotional stress can cause a flare-up. For some people, usually children, certain foods can also trigger eczema. Skin staph infections can cause a flare-up in children as well. People with eczema usually have very dry skin and “allergic shiners” (an extra crease across their lower eyelids). They are also more at risk for other skin infections.
Preventing the eczema itch is the main goal of treatment. Do not scratch or rub your rash. Applying cold compresses and creams or ointments is helpful. Also, remove all irritants that aggravate your condition from your environment. If a food is identified as the cause, it must be eliminated from your diet.
Topical corticosteroid cream medications and topical calcineurin inhibitors are most effective in treating the rash. Antihistamines are often recommended to help relieve the itchiness. In severe cases, oral corticosteroids are also prescribed. If a skin staph infection is suspected to be a trigger for your eczema flare-up, antibiotics are often recommended.
Source: American Academy of Allergy, Asthma & Immunology, www.aaaai.org
This article was originally published in Coping® with Allergies & Asthma magazine, July/August 2011.