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.
Skin 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 skin 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 skin 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 ticks, sometimes you should 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 skin 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 skin 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 skin 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 skin rash doesn’t keep interfering with your life.
Tips for preventing skin rashes
You can lower your chances of developing a skin rash by:
- Wearing protective clothing when going outdoors to protect from sunburn, insect bites and stings, and other environmental irritants.
- Avoiding topical products that contain alcohol or strong fragrances, especially if you have sensitive skin.
- Choosing mild, unscented and hypoallergenic soaps, cleansers and moisturizers.
- Using a gentle cleanser without harsh chemicals to prevent your skin from becoming overly dry and irritated.
- Avoiding contact with people who have contagious skin rashes.
- Being aware of existing allergies you may have and taking appropriate measures accordingly.
- Paying attention to any changes in the condition of your skin and take appropriate measures quickly if needed.
Eating a healthy diet that is rich in whole grains, fruits, vegetables, omega 3 fatty acids, and probiotics.
Diagnosing skin rashes
Diagnosing a skin rash can be tricky since there are many possible causes. Your healthcare provider can examine the rash, assess your symptoms, and review your medical history. Certain tests can be conducted to help diagnose the cause of the rash, including:
- Allergy test: Your healthcare provider can expose your skin to small amounts of potential allergens, looking for a reaction that may indicate an allergy such as redness, swelling or a rash.
- Biopsy: Your healthcare provider can take a biopsy sample of your skin to check for viral or bacterial infections that may be causing your rash.
Blood test: A blood test may be performed to detect the presence of certain antibodies in your blood from systemic illnesses which can cause skin diseases and rashes.
FAQs about skin rashes
Skin rashes may result from several factors, including allergies, infections, environmental irritants, and existing skin conditions.
Skin rash symptoms can vary based on the type and cause of the rash, but typically include red, itchy skin, bumps, blisters, or scaly patches on the skin.
Depending on the cause, some skin rashes may be contagious. For instance, rashes caused by fungal or viral infections may be spread through skin-to-skin contacts.
There are several home remedies for skin rashes, such as gently washing with warm water, taking oatmeal baths, or applying calamine lotion and/or hydrocortisone creams. However, it’s advised to monitor the rash and seek medical attention if the rash worsens.
It’s recommended to see a doctor if the rash develops blisters or open sores, spreads quickly, lasts for an extended period of time, has green or yellow fluid, or causes significant discomfort and pain.
Certain foods can trigger skin rashes, especially if the individual is allergic to them. Foods that can cause allergic reactions leading to skin rashes may include peanuts, shellfish, milk, and wheat.
MedlinePlus: National Library of Medicine. Rashes, Also called: Dermatitis, Skin rash (https://medlineplus.gov/rashes.html)
American Academy of Dermatology Association. Rashes (https://www.aad.org/public/everyday-care/itchy-skin/rash)