Rash questionnaire
Use our free symptom checker to find out what's causing your rash.
12 most common cause(s)
What is a rash?
A rash is an outbreak of lesions (spots) on the skin. The spots can be pink or red and may include blisters, pus-filled bumps, or scaling. Rashes can be itchy or painful, but in some cases you may have few or no symptoms. A rash can develop in one specific area or it may affect your entire body.
Common rashes include contact dermatitis (caused by poison ivy, for example), atopic dermatitis (eczema), psoriasis, hives, and shingles. Viruses, from everyday illnesses to chickenpox, are often the cause of rashes in children.
Most rashes go away in 1-2 weeks. Others may be caused by a lifelong condition that isn’t curable, such as psoriasis. The good news is that your dermatologist can treat your rashes to help them get better faster and soothe symptoms such as itching. And even if you have a rash that can’t be cured, there are treatments that can improve the look and feel of your skin.
Symptoms
- Red or pink bumps (papules) or flat patches with or without scale, blisters, or crust
- Itching or pain
- Can just be in one area of the body or all over the body
- You may also have a fever or cold symptoms if you have a viral rash
How do you diagnose a rash?
"Your doctor may have to do a “workup” to help figure out the cause of the rash. This may include a culture of the rash (testing for bacteria or viruses) or a skin biopsy (taking a piece of skin and sending it to the lab). But many rashes can be diagnosed instantly when they have a classic appearance—like shingles, psoriasis, and poison ivy."—Dr. Lauren Levy
Causes
1. Contact dermatitis
Contact dermatitis is an allergic reaction that occurs when your skin comes in contact with an allergen. The allergen may be a plant (like poison ivy or poison oak), a product (like makeup, shampoo, body wash, or moisturizer), or even a dye in your clothes. The rash can look like red or pink itchy bumps (often with blisters).
Common: About 15–20% of the population is affected by contact dermatitis [Source: American Academy of Allergy, Asthma & Immunology].
Other symptoms you may have:
- Itching
- Swelling of the affected area
Treatment and urgency: Contact dermatitis usually isn’t dangerous, but some allergic reactions can be life-threatening. Go to the ER if you have swelling of the face or lip or difficulty swallowing or breathing.
It may be obvious what you’re reacting to, like from poison ivy or a cream that gave you a rash. If you don’t know the cause, see a dermatologist or allergist and ask about allergy testing.
Most rashes should go away in about a week. Over-the-counter (OTC) topical steroids and antihistamines can treat the rash and itching. If you still have the rash after a week or it’s spreading, your doctor may prescribe stronger topical steroids.
2. Folliculitis
Folliculitis is when hair follicles become inflamed, causing red bumps that may be filled with pus. It occurs where there are a lot of hair follicles, such as the armpits, thighs, buttocks, or upper back. It can be from a bacterial infection, like staphylococcus aureus or pseudomona.
In some cases, you can develop folliculitis without an infection. This is usually a chronic irritation of the hair follicles from sweating, shaving, and wearing tight clothing.
Very common
Other symptoms you may have:
- Itching
Treatment and urgency: You can try using OTC treatments, such as a daily benzoyl peroxide wash that can be left on and rinsed off in the shower. Give the wash about 10-14 days to take effect.
Shaving less often, changing the razor blade frequently, and wearing loose clothing can help control non-bacterial folliculitis. If there’s pus in the bumps, you don’t see any improvement from using OTC benzoyl peroxide, or you were in a hot tub a few days before the rash appeared, see your dermatologist. You may need to be treated with topical or oral antibiotics.
Rash questionnaire
Use our free symptom checker to find out what's causing your rash.
3. Shingles
Shingles is caused by the varicella zoster virus, the virus that causes chicken pox. Once you’ve had chicken pox, the virus remains inactive in your nerve roots. But in many people, it can become reactivated later in life, causing shingles.
This is a blistering rash that usually occurs along a nerve and can be very painful. The rash most commonly develops on the trunk (torso) but can occur on any part of the body. There is a vaccine for shingles (Shingrix) that’s recommended for adults 50 and older.
Very common: 1 in 3 people will develop shingles in their lifetime [Source: CDC].
Other symptoms you may have:
- Shooting pain that may occur before a rash emerges
- Fever
- Red rash with overlying blisters that appear in a line on one side of your body
Treatment and urgency: You should see your primary care doctor as soon as possible because early treatment can reduce how long it lasts, and may lower your risk of complications. Urgent treatment is particularly important if the rash is near your eyes, as the virus can lead to vision impairment and even blindness. Go to the ER if you have a high fever, become confused, or the blisters are spreading all over your body.
Your doctor will prescribe an oral antiviral medication (Valtrex) and may also give you a prescription for gabapentin to help reduce nerve pain. The rash usually goes away in a week with treatment but the pain sometimes lasts longer.
4. Hives
Hives are swollen, itchy welts that usually appear suddenly. The welts appear on the stomach, back, and extremities, though the face is sometimes affected. They can be a reaction to medication, food, or a virus.
Very common: About 20% of adults get hives in their lifetime [Source: American Family Physician].
Other symptoms you may have:
- Itching
- Swelling of the lips, face, or tongue
- Shortness of breath
- Diarrhea
Treatment and urgency: Minor hives are not an emergency, but there are times when hives are part of a serious allergic reaction. Go to the ER if you have difficulty breathing, have swelling of the face or lips, or feel like your throat is closing.
You can take OTC antihistamines for minor hives. If they don’t go away within a week, see your dermatologist.
5. Ringworm
Ringworm is a circular rash caused by a fungus (dermatophyte) that is transmitted by sharing towels, an infected pet, or by touching shared surfaces such as gym mats. While ringworm can occur on any part of the body, it often appears on the arms and legs.
Very common: Many people get this fungus at some point in their lifetime.
Other symptoms you may have:
- Scaling skin
- Itching
- Pus-filled bumps at the edge of the rash
Treatment and urgency: You can treat it at home with OTC antifungal treatments such as terbinafine (Lamisil). If it doesn’t improve after 2 weeks of treatment, see your dermatologist.
You may be prescribed topical or oral antifungal medication to treat the rash. Keep the rash covered and do not let others touch it as it is highly contagious. Avoid sharing towels, linens, and clothing with others.
6. Heat rash
Also referred to as prickly heat, heat rash develops when the sweat glands become blocked, leading to small red bumps on the back and chest. It often happens when the weather is hot and humid, and can affect newborns who are swaddled for most of the day. Heat rash may also occur when your body temperature rises, like when you have a fever.
Common: The most common type of heat rash, miliaria rubra, occurs in up to 30% of people [Source: UpToDate].
Other symptoms you may have:
- Itching
Treatment and urgency: Heat rash generally disappears on its own. Wearing looser and lightweight clothing, applying cool compresses to the affected areas, and bringing down your body temperature can help it go away faster. If the rash doesn’t clear up, OTC topical steroids and a soothing anti-itch lotion (like Sarna) or OTC oral antihistamines can help with symptoms.
7. Lyme disease
Lyme disease is caused by a bacteria called Borrelia that is transmitted through ticks. If untreated, the infection can spread to your joints, heart, and nervous system.
During the earliest phase of Lyme disease—typically 1-2 weeks after you’re bitten by an infected tick—you may develop a rash called erythema chornicum migrans. It can occur on any part of the body where the tick attaches (even the scalp) or in an area that isn’t near the bite. The rash looks like a target that spreads and gets larger over time. It may also be itchy.
Common: It’s estimated that approximately 476,000 people get Lyme disease each year in the U.S.[Source: CDC].
Other symptoms you may have:
- Fevers
- Joint pain (arthritis)
- Fatigue
- Muscle aches
- Headaches
- Swollen glands
Treatment and urgency: If you think you have Lyme disease, see your doctor as soon as possible. While the rash usually goes away on its own without any treatment in a couple of weeks, other parts of your body may be affected by the bacteria.
Lyme disease is treated with several weeks of oral antibiotics such as doxycycline. It is important to treat Lyme disease right away because complications can occur if it is not treated.
8. Scabies
Scabies is a highly contagious rash caused by an infestation of tiny, burrowing mites. The rash typically appears as small pink red bumps in between the fingers, on the wrists, and around the belly button. It can occur in people of all ages and spreads easily in group settings, such as nursing homes and long-term care facilities.
Common
Other symptoms you may have:
- Severe itching that may last longer than the rash
Treatment and urgency: See your doctor as soon as possible if you think you have scabies. Since it’s very contagious, early treatment can help prevent you from spreading it to others.
Scabies is treated with topical or oral antiparasitic medications, such as permethrin or ivermectin. Everyone in your household should be treated for the condition as well. Washing all of your clothes and linens in hot water is also necessary if you’ve been diagnosed with scabies.
9. Eczema
Eczema, or atopic dermatitis, causes dry, itchy, red, and scaly skin. The rash commonly appears on the creases of the elbows or behind the knees but may also affect the face (the eyelids in particular) and palms of your hand. Eczema occurs when the skin’s barrier is impaired, which causes your skin to lose water.
Common: Eczema affects about 9.6 million children and 16.5 million adults in the U.S. [Source: National Eczema Association].
Other symptoms you may have:
- Itching
Treatment and urgency: You may be able to treat eczema at home with skincare products and OTC topical steroids. If there’s no improvement after a week of home care, see your doctor. You may need to be treated with prescription topical steroids and other topical nonsteroidal anti-inflammatory medications. In more severe cases, immunosuppressive oral or injectable medications or ultraviolet light therapy may be recommended.
10. Psoriasis
Psoriasis is a chronic autoimmune condition that speeds up the growth cycle of skin cells, causing skin to become red and flaky. It can occur anywhere on the body but most commonly affects the scalp, elbows, and knees. Psoriasis sometimes occurs with joint pain; this condition is called psoriatic arthritis.
Common: Psoriasis affects 3% of adults in the U.S. [Source: JAMA Dermatology].
Other symptoms you may have:
- Dandruff
- Brittle nails
- Joint pain
Treatment and urgency: See a dermatologist to treat your psoriasis. Treatment includes topical steroids, ultraviolet light therapy, and oral or injectable immunosuppressant medication. Because it’s a chronic condition, you will need to be treated over the long term.
11. Drug allergy
A drug rash is an allergic reaction to a medication that usually occurs anywhere from 4-7 days after starting a new medication. Antibiotics are a common cause of drug rashes. The rash looks like red patches on the stomach, chest, and back that spread to the arms and legs.
Relatively uncommon
Other symptoms you may have:
- Itching
Treatment and urgency: Call your doctor if you think you’ve developed a reaction to medication. They will likely tell you to stop taking the medication. Rarely, life-threatening reactions may occur. See your doctor immediately if you have a fever, skin pain, oral or genital blisters or pain, blisters on the skin, or facial swelling.
Drug rashes usually go away 10-14 days after you stop taking the medication. Treatment includes OTC or prescription topical steroids, oral steroids (if the rash is severe), and oral antihistamines to help with itch. You should not take the medication that caused the rash again.
Does amoxicillin cause a rash with mono?
"If you have mononucleosis (Epstein Barr Virus), which is a viral syndrome, and are prescribed amoxicillin, there is a very high likelihood you can develop a rash that looks like a drug allergy. This is from the interaction from the viral infection and the antibiotic and does not mean you are allergic to amoxicillin."—Dr. Levy
12. Pityriasis rosea
Pityriasis rosea is caused by a virus and is most common in children, teenagers, and young adults. In some cases, you may develop cold symptoms (runny nose, cough, fever) before the rash develops.
The rash often begins as one scaly patch, usually on the chest, back, or abdomen. New patches then spread on the back and may include papules (bumps). The condition can also affect the scalp.
Relatively common: Pityriasis rosea affects 0.5–2% of the population [Source: National Institutes of Health].
Other symptoms you may have:
- Itching
Treatment and urgency: Pityriasis rosea usually goes away on its own in 1-2 weeks without treatment. But if the rash is itchy, see your doctor, who may treat you with topical steroids to help relieve itching. Since the rash is caused by a virus, your doctor may prescribe an antiviral medication (Valtrex) to speed recovery.
What are the most common childhood rashes?
A number of rashes only occur in children or are more common in them. They include:
- Cradle cap (seborrheic dermatitis). A rash on the scalp of infants.
- Diaper rash. Redness or irritation in diaper area
- Impetigo. Yellow crusting around the nose, mouth, arms, and legs, mostly affecting children 6 and under.
- Fifth disease. Viral infection with red cheek rash and fever, mostly affecting children ages 5 to 15.
- Hand, foot, and mouth disease (coxsackie virus). Virus causing painful rash in the mouth, hands, and feet.
How long does a poison ivy rash last?
"If you are given a short course (like 5 days) of oral steroids for poison ivy, your rash may get temporarily better but then quickly worsen and even spread more after you finish the steroids. This is called a rebound reaction. Severe or spreading poison Ivy often requires 2-3 weeks of treatment with oral steroids instead of a 5-day or shorter course."—Dr. Levy
When to worry about a rash
- You should be concerned about a rash that causes pain, blisters on the skin, or oral or genital ulcers. Get medical attention immediately if you experience any of these symptoms, which may be signs of a severe medication reaction.
- If you have a rash with a high fever, confusion, or severe headache, go to the ER. These are signs you may have an infection as well.
- Always call your pediatrician if your child has a rash with a fever, which often means your child has a viral infection.
- See your doctor right away if you have a red rash that spreads and causes pain, pus drainage, and fever. You may have a potentially serious skin infection called cellulitis.
- If a rash is spreading or isn’t getting better with 10-14 days of OTC treatment, check in with your doctor.
How do I clear up a rash?
- Stop applying any essential oils and other irritating products on your skin.
- Avoid using irritating home remedies, such as apple cider vinegar, on your rash.
- Use mild, unscented soap and water and hypoallergenic products on your skin.
- Try using an OTC hydrocortisone cream and antihistamines, such as Zyrtec or Benadryl, to help relieve the rash and itching.
FAQs
What kind of rash do I have?
To get the proper diagnosis, visit a doctor. They will ask you the following questions: When did your rash start? Have you had a rash like this before? What have you used to treat the rash before you came to see me? Do you have a fever, cough, diarrhea, headache, or other symptoms? Is the rash itchy or painful?
Your doctor will study the rash, paying attention to the color, location, and shape of the rash. They will also check for pus or crusting, which may be signs of infection. The doctor may take a swab or skin biopsy of the rash to test for viruses or bacteria.
What types of skin rashes itch?
The majority of rashes are itchy because the skin is inflamed. The good news is that the overwhelming majority of itchy rashes, although annoying and unpleasant, don’t cause long-term harm or complications.
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