A Rash or Skin Allergies?

Patient Expert

I've developed a rash recently and I don't know if it's eczema or just a skin allergy. I changed detergents recently. Does this have anything to do with my rash?

In its most fundamental meaning, "eczema" is simply a type of skin inflammation. Collectively, skin inflammations resulting from allergies or physical contact are referred to as "dermatitis." While the name may sound serious, dermatitis can range from mild-a small patch of flaking, dry skin-to severe-rashes that can be painful and cause cracks in the skin.

When we use the term "eczema," we commonly conflate the condition with atopic dermatitis, which doctors believe is an autoimmune-related disorder that causes a chronic itchy rash. However, if your rash only appeared recently, it's highly unlikely that you are experiencing atopic eczema. Atopic eczema is a hereditary disorder that most often affects people in childhood and can either worsen or improve as they age.

A more recent, first-time rash is more likely the result of coming into contact with a skin irritant or allergen. Contact dermatitis refers to rashes caused by physical exposure to external substances. Common culprits of these rashes include cosmetics, fragrances, nickel, latex, poison ivy, and many household detergents. Rashes resulting from contact dermatitis are limited to the areas of the skin that have come into direct contact with the allergens. They may be accompanied by hives and may cause intense burning or itching.

If you have an idea of what has caused the rash, then remove the allergen immediately from your environment. Contact dermatitis rashes usually take several days (sometimes even weeks) to fade away. If the rash returns or occurs in another patch of skin after you remove the suspected allergen, it's possible that the reaction is coming from another source. At this point, I recommend going to see an allergist, who will be able to help narrow the list of potential irritants so that you can take steps to avoid causing more rashes.

Once you figure out what the culprit is, avoid coming into contact with the allergen. If you do touch the irritant, wash the area with soap and water immediately. If the area blisters, apply cold compresses. Use calamine lotion or hydrocortisone cream to relieve itching and aloe to sooth burning. Occasionally, taking a Benadryl or a similar over-the-counter antihistamine medication can help reduce the allergic reaction. Aveeno's oatmeal-infused Soothing Bath Treatment can also take the edge off itching and inflammation if the rash covers a large area of the skin. While it's tempting to scratch, refrain from doing so since this can lead to infection and scarring.

After treating with these home remedies, if your rash does not begin to fade and the inflammation worsens, seek advice from a dermatologist. A doctor can offer a prescription corticosteroid ointment to reduce inflammation or a prescription antihistamine to reduce the allergic reaction. If the rash is large, a doctor can also prescribe a systemic corticosteroid in the form of pills or an injection. Just make sure to finish the full program of oral corticosteroids in order to ensure complete treatment.