Allergic Skin Conditions
Skin rashes and irritations are common - most people develop a skin reaction at some point in time. When an immune response to an allergen is responsible for triggering a skin irritation, it is referred to as an allergic skin condition.
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 to 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 appear on any area of the body. Most hives are acute and go away within a few days to weeks. There is often an association of exposure to an allergen (food, medication, vaccine, bee sting) or an association with an illness (viral or bacterial infections particularly in children) with the development of acute hives. Hives can also be caused by physical factors such as cold, heat, exercise, pressure and exposure to sunlight. Chronic urticaria is defined as hives lasting for more than 6 weeks; these may come and go for several months or even years. Your allergist may prescribe antihistamines to treat acute and chronic urticaria. If the lesions prevail and the condition is chronic despite taking antihistamines, then a monoclonal antibody, or biologic, may be prescribed as treatment.
If the cause can be identified, you should avoid that trigger. However, most chronic urticaria cases are not related to allergy. Routine testing, such as blood counts or allergy screens, are not recommended as they are unlikely to determine a cause and do not make a difference in treatment strategies.
While related to hives, angioedema is swelling that affects the deeper layers of the skin. It is usually not red or itchy and often involves the eyelids, lips, tongue, hands or feet. Angioedema commonly occurs with hives but can also occur on its own.
Dermatitis refers to inflammation of the skin that produces a red, scaly, itchy and sometimes painful rash. Two of the most common types of dermatitis are atopic dermatitis (often called eczema) and contact dermatitis. Contact dermatitis is caused by contact with a biological or chemical material and is typically divided into those caused by an allergen, and those caused by an irritant.
Atopic Dermatitis (Eczema)
Atopic Dermatitis is a chronic skin condition that usually begins in infancy or early childhood and is often associated with other allergic diseases, such as food allergy, allergic rhinitis and asthma. It has also been associated with eosinophilic esophagitis.
Atopic dermatitis may have many different triggers. Potential triggers include animal dander, pollens, dust mites, sweating, other infections, stress, or contact with irritants like wool or soaps. Foods are not common triggers of eczema, except rarely in infants and young children. Skin staph infections can cause flare-ups in children as well.
Repairing the skin barrier, preventing itch and treating the underlying rash are the main goals of treatment. It is important not to scratch or rub the rash. Applying cold compresses and moisturizing creams or ointments is helpful. It is also important to avoid all irritants that aggravate your condition. Reduce exposure to any known triggers under the guidance of your allergist.
Corticosteroid and other anti-inflammatory creams such as pimecrolimus, tacrolimus, crisaborole and ruxolitinib that are applied to the skin are most effective in treating the rash. Antihistamines are often recommended to help relieve the itchiness even though they often have limited effectiveness. In more severe cases, certain injectable biologic medications such as dupilumab or tralokinumab may be helpful. Oral immunosuppressants (JAK inhibitors) can also be prescribed for severe disease. If a skin staph infection is suspected to be a trigger for an eczema flare-up, antibiotics may be recommended.
Irritant contact dermatitis occurs when a material damages the skin at the point of contact due to the caustic nature of the chemical rather than to an immune response. Irritant contact dermatitis is often more painful, burning or stinging than itchy. The longer your skin is in contact with the material, or the harsher the substance, the more severe your skin reactions will be. These reactions appear commonly on the hands and are frequently due to materials contacted in the workplace.
For irritant contact dermatitis, treatment includes avoiding the substance causing the reaction, and restoring the protective barrier of your skin if breakdown or inflammation has occurred. Wearing personal protective equipment such as gloves may be helpful. Identifying and avoiding the trigger will relieve your symptoms and prevent lasting damage to your skin.
Allergic contact dermatitis occurs when skin contact with a specific material triggers an immune response manifesting as a rash. The most common example is the itchy, red, blistered reaction experienced after touching poison ivy. With poison ivy, the allergic reaction is caused by an oily plant chemical called urushiol. Other reactions may occur from touching other areas of your skin or clothing that the plant has contacted. However, once the allergen has been washed off your skin, you cannot develop more reactions from touching the rash or blisters. These allergic skin reactions can develop 24 to 48 hours after contact. Once a reaction starts, it may take 14 to 28 days to go away, even with treatment.
Other substances that frequently cause allergic contact dermatitis include metals (for example, nickel), personal care products like cosmetics that contain fragrances and preservatives, hair dyes, and rubber (latex) products. Even certain topical medications like antibiotic creams (neomycin) or steroids can cause an allergic contact dermatitis.
Treatment depends on the severity of the rash. Cold soaks and compresses can offer relief for the early, itchy blistered stage of a rash. Oral antihistamines may also relieve itch. Topical corticosteroid creams are often prescribed to reduce the allergic inflammation. For severe reactions such as poison ivy, oral prednisone may be recommended as well.
To prevent the reaction from recurring, the key is to avoid contact with the offending material. Your allergist may conduct tests to specifically identify the responsible allergen causing the rash (for example, a patch test), so you know to avoid it in the future.
• 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. These typically last a few hours, and less than 24 hours, before resolving. 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, knees, wrists and ankles. It usually starts in childhood and is associated with other allergic diseases.
• When certain materials 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.
By visiting the office of an allergist, you can expect an accurate diagnosis, a treatment plan that works and educational information to help you manage your disease and feel better.
The AAAAI's Find an Allergist / Immunologist service is a trusted resource to help you find a specialist close to home.
Find out more about skin allergies.
If you would like to order a brochure on this topic visit the AAAAI Store.
What is a skin allergy?