Exposure to allergens in your environment can cause an an allergic reaction, which occur when histamines are produced by your cells and attack histamine receptor sites. During this reaction your body can respond to the allergic reaction in a number of ways, including sneezing, itchy eyes and skin, runny nose or skin rashes. Allergy symptoms usually subside naturally toward the end of allergy seasons in summer and fall, but medications and other sources of treatment can help alleviate allergies. Visit your doctor or allergist if a skin rash persists after attempting to treat it, as it may be a symptom of a serious medical condition.
Take allergy medication. Antihistamines are an over-the-counter allergy medication that reduces current allergy symptoms and prevents future flare-ups by coating your histamine receptor sites, which inhibits histamines from attaching to the receptor sites. Medication should be taken consistently to maintain allergy control. Side effects of antihistamines include headache, drowsiness, nausea, vomiting or constipation.
Apply hydrocortisone cream to the rash. Skin rashes caused by allergies can be soothed by applying hydrocortisone cream to the skin rash two to three times daily until the rash disappears. Clean the rash with a mild soap and warm water to remove bacteria, followed by smoothing a thin layer of cream over the rash. Wrap the rash with clean medical bandages to protect it from further irritation.
An oatmeal bath can also help soothe irritation when used daily, according to William E. Berger, author of "Allergies and Asthma for Dummies." Purchase oatmeal specifically for bathtub use at your local drugstore or natural health store.
Remove the allergen from your environment. Although medication can help reduce symptoms, it is important to thoroughly clean your home to remove any traces of the allergen. Use an air purifier to clean the air of your home by ridding it of inhaled allergens. Sweep your floors weekly, and mop every two to three weeks to cut down on dust.
Change your laundry detergent, as the allergic reaction may be caused by an abrasive soap you are using. Be sure to purchase detergents that are labeled as fragrance-free or hypoallergenic, as these detergents contain little if any harsh chemicals that irritate your skin. You can also remove some of the remaining chemicals on your clothes by setting your washer to include an extra rinse cycle, according to the Mayo Clinic.
Avoid scratching. Scratching the rash may seem like a good idea when the itching seems unbearable, but scratching it can cause the skin to break and leave you susceptible to infection. Wrap your arm in a bandage if the scratching intensifies, according to the Mayo Clinic. You can soothe your itching by applying a cold compress to the rash for 20 minutes at a time, according to Berger.