A rash is an area of skin that has a noticeable change in texture and/or color, and is irritated, swollen, itchy and/or painful. Rashes are a symptom of many different medical conditions, from allergies to poison ivy to an adverse reaction to heat.
Rashes have a range of causes
There are many different types of rashes, with many different causes. Some don’t require any medical treatment, while some may be a symptom of a serious medical condition that requires immediate medical attention.
See your provider for a rash that concerns you
Most rashes are not life-threatening. Some, though, are a symptom of a serious underlying condition.
If you have a skin rash that concerns you, see your primary care provider for a diagnosis and possible treatment.
Common types and causes of rashes
Skin rashes are caused by a variety of factors and present in different ways in the affected areas. Your primary care provider or dermatologist will be able to determine the cause based on the type of rash and other factors.
The most common types and causes include:
- Atopic dermatitis, or eczema. One of the most common rashes, this is a chronic condition that periodically causes red, itchy skin on the hands, feet, ankles, neck, upper body and limbs.
- Bug bites. For some bites, like tick bites, you may need to get medical attention to check for Lyme disease.
- Cellulitis. A bacterial infection, causing a red, swollen and painful rash. See your provider right away, because the infection can become life-threatening if left untreated.
- Chickenpox. A virus that causes red, itchy blisters all over the body. Chickenpox usually affects children. The same virus causes shingles in adults.
- Contact dermatitis. This common rash occurs from direct contact with a foreign substance that causes an adverse reaction, such as:
- Beauty products, soaps and laundry detergent.
- Chemicals in rubber, elastic or latex.
- Clothing dyes.
- Poisonous plants, such as poison oak, poison ivy or poison sumac.
- Diaper rash. A common skin irritation caused by chafing, sensitive skin or sitting too long in a dirty diaper.
- Fifth disease. A viral infection that causes a red, flat rash on the cheeks, upper arms and legs.
- Hand, foot and mouth disease. A viral infection that causes red lesions on the mouth and a rash on the hands and feet.
- Heat rash, also called prickly heat and miliaria. Caused when blocked sweat ducts trap perspiration under the skin, resulting in itchiness and blisters or deep, red lumps.
- Hives. An allergic reaction that causes sudden swollen, red bumps that may itch.
- Impetigo. A contagious bacterial infection that causes an itchy, crusty rash and yellow, fluid-filled sores on the face, neck and hands.
- Kawasaki disease. A rare but potentially fatal illness that present with a rash and fever in the early stages. Seek immediate medical attention.
- Lupus. An autoimmune disease that triggers a butterfly-like rash on the cheeks and nose.
- Measles. A viral respiratory infection that causes widespread itchy and red bumps.
- Medications. Rashes can form due to an allergic reaction, side effect or photosensitivity.
- Psoriasis. A scaly, itchy, red rash forms along the scalp, elbows and joints.
- Ringworm. A fungal infection that causes a distinctive ring-shaped rash. The same fungus causes jock itch and athlete’s foot.
- Rosacea. A chronic skin condition of unknown cause, characterized by redness on the face.
- Scabies. An infestation by tiny mites, causing a bumpy, itchy rash.
- Scarlet fever. An infection due to group A Streptococcus bacteria that causes a red, sandpaper-like rash.
- Seborrheic eczema. A type of eczema that affects the scalp and causes redness, scaly patches and dandruff. In babies, it is called crib cap.
- Shingles. A viral infection caused by the varicella-zoster virus, the same virus that causes chickenpox. Shingles causes a painful rash, usually appearing as a single stripe of blisters that wraps around either the left or the right side of your torso.
When to see your primary care provider about a rash
Most rashes are not life-threatening, but some are a symptom of a serious underlying condition. See your provider right away if you have a rash plus any of the following symptoms:
- Blistering or open sores in the rash. Could be an allergic reaction, a reaction to medication or have an internal cause.
- Infected rash. Has yellow or green fluid, swelling, crusting, pain and/or warmth in the area of the rash, or a red streak coming from the rash.
- Painful rash. Many rashes are itchy and irritating, but pain can be a sign of something else.
- The rash appears all over your body, which could indicate an infection or allergic reaction.
Seek immediate medical help if you have a rash plus one or more of the following:
- A fever. Could be caused by a serious allergic reaction or an infection, including scarlet fever, measles, mononucleosis and shingles.
- The rash is sudden and spreads rapidly, which could be the result of a serious allergy.
The best ways to treat a rash
Fortunately, most rashes clear up fairly quickly and can be treated at home with simple remedies. However, some rashes need long-term treatment, so you should see your primary care provider for a proper diagnosis and the right treatment plan for your rash and any underlying cause.
Your plan may start with steps you can take at home to relieve discomfort and speed healing, such as:
- Avoiding triggers, such as cosmetics or lotions.
- Letting the rash breathe whenever possible.
- Nonprescription hydrocortisone creams or calamine lotion.
- An oatmeal bath.
- OTC medications. Oral antihistamines can help with itching, and acetaminophen (Tylenol) or ibuprofen (Advil) can treat mild pain.
- Patting dry the rash instead of rubbing it dry.
- Using unscented moisturizers for eczema rashes.
- Using gentle cleansers.
- Washing your skin and hair with warm water instead of hot water.
If needed, dermatologists can provide specialized care
Depending on the type of rash you have, you may need prescription medications and/or ointments to better relieve your discomfort and get rid of the rash.
Your provider will work with you on your personalized treatment plan, which may include a referral to a dermatologist for more specialized care and long-term treatment to make sure a rash doesn’t keep interfering with your life.