A rash is a noticeable change in the texture or color of the skin. The skin may become itchy, bumpy, chapped, scaly, or otherwise irritated. Rashes are caused by a wide range of conditions, including allergies, medication, cosmetics, and various diseases.
Contact dermatitis is a common cause of rashes. Contact rashes occur when you touch something that causes a reaction. Most contact rashes can be treated without the help of a doctor. A rash may be itchy, but scratching can make it worse and prevent it from healing.
Contact dermatitis can be caused by coming into contact with:
- beauty products, soaps, and laundry detergent
- dyes in clothing
- chemicals in rubber, elastic, or latex
- poisonous plants such as poison oak, poison ivy, or poison sumac
Drug rashes are caused by medication. They can form as:
- an allergic reaction
- a side effect
- a result of sensitivity to sunlight
Other types of rashes include:
- eczema: a common rash for people with asthma or allergies. The rash is often reddish and itchy, with a scaly texture.
- bug bites: tick bites are of particular concern, as they can transmit disease
- psoriasis: a scaly, itchy, red rash that forms along the scalp and joints
- dandruff: an itchy, flaky rash on the scalp. On an infant, dandruff is called cradle cap.
- seborrheic dermatitis: dandruff that occurs on the ears, mouth, nose, or somewhere besides the scalp
Children are particularly prone to rashes from illnesses such as:
- chicken pox: a virus that causes itchy blisters
- measles: a respiratory infection
- scarlet fever: a bacterial disease (streptococcus infection) that requires antibiotics
- hand, foot, and mouth disease: a virus that causes red lesions
- fifth disease: a red, flat rash on the face, upper arms, and legs
- Kawasaki disease: an autoimmune disease that affects the blood vessels
- impetigo: a bacterial infection that forms red, wet sores that crust over
Medical diseases can cause rashes as well. These include lupus erythematosus (a long-term disorder of the autoimmune system) and rheumatoid arthritis (long-term inflammation of the joints).
Most contact rashes can be treated at home by following these guidelines:
- Use gentle cleansers instead of soap.
- Use warm water instead of hot water for washing.
- Pat rash dry instead of rubbing.
- Let the rash breathe—do not cover with clothing, if possible.
- Stop using new cosmetics or lotions, as these may have triggered the rash.
Do not scratch your rash. If it itches, try an over-the-counter hydrocortisone cream (one percent). Lotion with calamine can soothe rashes caused by chicken pox and poison ivy, poison oak, or poison sumac.
An oatmeal bath can soothe rashes caused by shingles, eczema, or psoriasis. Moisturizing lotion may help eczema symptoms.
Dandruff is caused by weather, oily skin, stress, fatigue, or not washing one’s hair enough. Dandruff can usually be treated by washing your hair and scalp regularly with dandruff shampoo. Medicated dandruff shampoo is commonly available at drugstores, though your doctor can prescribe stronger types.
You can take acetaminophen or ibuprofen for mild pain associated with the rash. Check with your healthcare provider before taking these drugs if you have liver or kidney disease, or a history of stomach ulcers or GI bleeding.
Seek immediate medical attention if you experience any of the following:
- increasing pain or discoloration
- tightness of the throat or difficulty breathing
- swelling of the face
- new pain or a new rash
- fever over 100.0 degrees F
- confusion or dizziness
- severe head or neck pain
- repeated vomiting or diarrhea
Contact your health care provider if you have:
- joint pain
- a sore throat or low fever
- red streaks or tender areas near the rash (it may be infected)
- been bitten by a tick
Your healthcare provider will examine your rash. Expect to answer questions about your rash, medical history, diet, and hygiene. Your healthcare provider may also:
- take your temperature
- order a test such as a skin biopsy, allergy test, or complete blood count
- take skin scrapings for analysis
- refer you to a specialist, such as a dermatologist
- prescribe medication to relieve your symptoms
You may be prescribed medication or medicated lotion. In some cases, skin surgery may be required.