An allergy or an allergic reaction is an immune response to an allergen, which refers to a substance that is usually not harmful, but considered to be foreign and dangerous by the immune system. One may not have a reaction on being exposed to the substance for the first time, however, one might develop hypersensitivity to that substance, which would give rise to allergic reactions on repeated exposure. Such substances might be inhaled, swallowed, or injected. Such reactions might sometimes be characterized by changes in the color and texture of the skin. Hives and allergic contact dermatitis are skin rashes that occur when the skin is exposed to an allergen. Inflammation of the skin could give rise to symptoms such as itching, redness, or swelling. Causes During a hives outbreak, red, itchy welts appear on the skin. The skin allergy occurs due to the release of histamines from the cutaneous mast cells into the bloodstream. Histamines are released in response to contact with an allergen. Food items like milk, shellfish, nuts, wheat, soybeans, and peanuts are some of the most common allergens. Pollen, mold, insect bites, pet dander, and drugs could also cause hives. The release of histamines causes fluid to leak from the superficial blood vessels under the skin. Generally, these eruptions have a red margin and a pale center. Their size, shape, and location changes rapidly. Old welts might fade, as the new ones appear in just a few hours. Allergic contact dermatitis is another inflammatory skin condition that occurs due to contact with allergens. Contact with pollen, latex, metal jewelry, cosmetics, fabrics, plants like poison ivy and poison sumac, etc., is known to trigger allergic reactions. At times, skin eruptions could be caused by irritant contact dermatitis. The skin becomes inflamed on coming into contact with cosmetics, metallic jewelry, synthetics or chemicals. Only the part of skin which has come in contact with the irritant gets affected. The duration of time for which the skin comes in contact with the irritant, extent of contact, and the type of irritant will determine the extent of inflammation. Atopic dermatitis or eczema could also be responsible for inflammation of the skin. Children could also get itchy bumps due to hives or papular urticaria. Babies are prone to developing diaper rash. If you use cloth diapers, make sure that the fabric softener or the laundry detergent is very mild. Watch out for any reactions after giving any antibiotic or baby food. Treatment If your skin is very itchy and red, you must see a dermatologist to avoid any complications. Emollients and medicated soaps or gel substitutes might be a better option, if a person is affected by contact dermatitis. If consumption of any food item triggers allergic reactions on your skin, don't consume such food items in future. Don't use cosmetic products, drugs, jewelry, or fabrics that may irritate your skin. Never scratch over the affected skin as that may make you susceptible to secondary bacterial infections. Take all possible steps to maintain a clean and dust-free environment. In order to prevent diaper rash in infants, make sure that your baby doesn't wear a wet or dirty diaper for a long time. Check the baby's genital area, groin, and upper thigh for any redness or itchiness. Use creams and lotions as prescribed by the pediatrician. Skin could become inflamed due to infantile eczema, hives, or irritant contact dermatitis. So, if you see dry or scaly skin accompanied with redness, consult a doctor soon. Rashes that are caused due to exposure to an allergen can be treated with antihistamines, medicated emollients, or steroids. The avoidance of the allergen or the irritant is the best way to prevent this skin problem. If you do observe patches of inflamed skin, stop yourself from scratching over the affected area. If the symptoms are severe, consult a dermatologist soon. Disclaimer: The information provided in this article is solely for educating the reader. It is not intended to be a substitute for the advice of a dermatologist.