Most people are bothered by skin irritations at some point in time. These irritations are so common and varied that they are called by different names, which can lead to confusion. When an allergen is responsible for triggering an immune system response, the irritation is an allergic skin condition.
Allergic Skin Disorder
Allergic Skin Disorders
There are several types of allergic skin conditions. An allergist/immunologist, often referred to as an allergist, has advanced training and expertise to determine which condition you have and develop a treatment plan to help you feel better.
Hives and Angioedema
Urticaria is the medical term for hives, which are red, itchy, raised areas of the skin. They can range in size and appear anywhere on your body. Most cases of hives are known as acute and go away within a few days or weeks, but some people suffer from chronic hives with symptoms that come and go for several months or years. Your allergist may prescribe antihistamines to relieve your symptoms.
Atopic Dermatitis (Eczema)
Eczema is a chronic skin condition that usually begins in infancy or early childhood and is often associated with food allergy, allergic rhinitis and asthma.
Certain foods can trigger eczema, especially in young children. Skin staph infections can cause flare-ups in children as well. Other potential triggers include animal dander, dust mites, sweating, or contact with irritants like wool or soaps.
Allergic Contact Dermatitis
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. Reactions can happen 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 may take 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. A common offender is neomycin, an ingredient in antibiotic creams.
Treatment depends on the severity of the symptoms. Cold soaks and compresses can offer relief for the early, itchy blistered stage of a rash. Topical corticosteroid creams may be prescribed. For severe reactions such as poison ivy, oral prednisone may be prescribed as well.
To prevent the reaction from returning, avoid contact with the offending substance. If you and your allergist cannot determine what caused the reaction, your allergist may conduct tests to help identify it.
• If you have red, bumpy, scaly, itchy or swollen skin, you may have a skin allergy.
• Urticaria (hives) are red, itchy, raised areas of the skin that can range in size and appear anywhere on your body. Angioedema is a swelling of the deeper layers of the skin that often occurs with hives.
• Atopic dermatitis (eczema) is a scaly, itchy rash that often affects the face, elbows and knees.
• When certain substances come into contact with your skin, they may cause a rash called contact dermatitis.
Feel Better. Live Better.
An allergist / immunologist, often referred to as an allergist, is a pediatrician or internist with at least two additional years of specialized training in the diagnosis and treatment of allergies, asthma, immune deficiencies and other immunologic diseases.
Skin Allergy Tests
Information from allergy tests may help your doctor develop an allergy treatment plan that includes allergen avoidance, medications or allergy shots (immunotherapy).
Allergy skin tests are widely used to help diagnose allergic conditions, including:
- Hay fever (allergic rhinitis)
- Allergic asthma
- Dermatitis (eczema)
- Food allergies
- Penicillin allergy
- Bee venom allergy
- Latex allergy
Skin tests are generally safe for adults and children of all ages, including infants. In certain circumstances, though, skin tests aren’t recommended. Your doctor may advise against skin testing if you:
- Have ever had a severe allergic reaction. You may be so sensitive to certain substances that even the tiny amounts used in skin tests could trigger a life-threatening reaction (anaphylaxis).
- Take medications that could interfere with test results. These include antihistamines, many antidepressants and some heartburn medications. Your doctor may determine that it’s better for you to continue taking these medications than to temporarily discontinue them in preparation for a skin test.
- Have certain skin conditions. If severe eczema or psoriasis affects large areas of skin on your arms and back — the usual testing sites — there may not be enough clear, uninvolved skin to do an effective test. Other skin conditions, such as dermatographism, can cause unreliable test results.
Blood tests (in vitro immunoglobulin E antibody tests) can be useful for those who shouldn’t undergo skin tests. Blood tests aren’t done as often as skin tests because they can be less sensitive than skin tests and are more expensive.
In general, allergy skin tests are most reliable for diagnosing allergies to airborne substances, such as pollen, pet dander and dust mites. Skin testing may help diagnose food allergies. But because food allergies can be complex, you may need additional tests or procedures.
Patch testing is a specialist procedure carried out by dermatology doctors to find out whether your skin condition is caused or aggravated by an allergy to substances which have come into contact with your skin. This is called contact allergy. Substances that cause an allergic reaction are called allergens. They can be found at home, at work or in leisure activities.
There are approximately 40 substances which are most frequently in contact with the skin such as natural rubber latex, preservatives, metals, perfumes, cosmetics, leather chemicals, lanolin and plants among others. Additional substances are sometimes added to this list if it is thought they may trigger your skin condition. You may also be tested with some of your own work or home products, such as personal toiletries.
Skin Prick Test
A skin prick test, also called a puncture or scratch test, checks for immediate allergic reactions to as many as 40 different substances at once. This test is usually done to identify allergies to pollen, mold, pet dander, dust mites and foods. In adults, the test is usually done on the forearm. Children may be tested on the upper back.
Allergy skin tests aren’t painful. This type of testing uses needles (lancets) that barely penetrate the skin’s surface. You won’t bleed or feel more than mild, momentary discomfort.
After cleaning the test site with alcohol, the nurse draws small marks on your skin and applies a drop of allergen extract next to each mark. He or she then uses a lancet to prick the extracts into the skin’s surface. A new lancet is used for each allergen.
To see if your skin is reacting normally, two additional substances are scratched into your skin’s surface:
- Histamine. In most people, this substance causes a skin response. If you don’t react to histamine, your allergy skin test may not reveal an allergy even if you have one.
- Glycerin or saline. In most people, these substances don’t cause any reaction. If you do react to glycerin or saline, you may have sensitive skin. Test results will need to be interpreted cautiously to avoid a false allergy diagnosis.
About 15 minutes after the skin pricks, the nurse observes your skin for signs of allergic reactions. If you are allergic to one of the substances tested, you’ll develop a raised, red, itchy bump (wheal) that may look like a mosquito bite. A nurse will then measure the bump’s size.
After the nurse records the results, he or she will clean your skin with alcohol to remove the marks.