Topic Overview
Healthy skin provides a barrier between the inside of the body and the outside environment. A rash means some change has affected the skin.
Rashes are generally caused by skin irritation, which can have many causes. A rash is generally a minor problem that may go away with home treatment. In some cases, a rash does not go away or the skin may become so irritated that medical care is needed.
In adults and older children, rashes are often caused by contact with a substance that irritates the skin (contact dermatitis). The rash usually starts within 48 hours after contact with the irritating substance. Contact dermatitis may cause mild redness of the skin or a rash of small red bumps. A more severe reaction may cause swelling, redness, and larger blisters. The location of the rash may give you a clue about the cause.
Contact dermatitis does not always occur the first time you are in contact to the irritating substance (allergen). Once you have had a reaction to the substance, a rash can occur in response to even very small amounts of the substance. Contact dermatitis is not serious, but it is often very itchy. Common causes of contact dermatitis include:
- Poisonous plants, such as poison ivy, oak, or sumac.
- Soaps, detergents, shampoos, perfumes, cosmetics, or lotions.
- Jewelry or fabrics.
- New tools, toys, appliances, or other objects.
- Latex. Allergy to natural rubber latex affects people who are exposed to rubber products on a regular basis, especially health care workers, rubber industry workers, and people who have had multiple surgeries. Latex allergies can cause a severe reaction.
Rashes may occur with viral infections, such as herpes zoster; fungal infections, such as a yeast infection (Candida albicans); bacterial infections, such as impetigo; and sexually transmitted diseases (STDs). Rashes may also occur as a symptom of a more serious disease, such as liver disease, kidney disease, or some types of cancer.
Rashes may also appear after exposure to an insect or a parasite, such as the scabies mite. You may develop a rash when you travel to a rural area or go hiking or camping in the woods.
A rash may be a sign of a chronic skin problem, such as acne, eczema, psoriasis, or seborrheic dermatitis. Other causes of rash include dry, cold weather; extremely hot weather (heat rash); and emotional stress. Emotions such as frustration or embarrassment may lead to an itchy rash.
The need for medical treatment often depends on what other symptoms are present. A rash that occurs with other symptoms, such as shortness of breath or fever, may mean another problem, such as a serious allergic reaction or infection.
Review the Emergencies and Check Your Symptoms sections to determine if and when you need to see a doctor.
Emergencies
Do you have any of the following symptoms that require emergency treatment? Call 911 or other emergency services immediately.
- Signs of shock
- Moderate to severe difficulty breathing, wheezing, or tightness in the chest
- Rapid swelling of the throat, tongue, lips, eyelids, or face
- Drooling and an inability to swallow
- A severe allergic reaction (anaphylaxis) to the same allergen in the past
- A rash that looks like bruises (purpura) or blood spots (petechiae) under the skin and that occurs along with mental changes, such as confusion, irritability, or extreme sleepiness
Check Your Symptoms
If you answer yes to any of the following questions, click on the "Yes" in front of the question for information about how soon to see a health professional.
Review health risks that may increase the seriousness of your symptoms.
| Note: |
If you have any of the following symptoms, evaluate those symptoms first.
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Do you have bruises (purpura) or tiny purple or red blood spots (petechiae) under the skin?
See significance of tiny purple or red spots if you need information to help you answer the questions below.
Review health risks that may increase the seriousness of your symptoms.
Call your health professional immediately if you answer "Yes" to any of the following questions.
Have you had any abnormal bleeding within the last 12 hours?
Do you have other signs of a serious illness? These symptoms may include:
- Severe neck stiffness or pain.
- Confusion or very irritable.
- Very sleepy and hard to wake up.
- Ongoing nausea or vomiting.
- Eyes very sensitive to light (photophobia).
- Unsteady on your feet that keeps you from standing or walking (ataxia or vertigo).
- New double vision, blurred vision, or blind spots in your vision.
- Very rapid, difficult breathing.
- Severe pain.
- New and different skin rash or severe bruises.
Call your health professional today if you answer "Yes" to the following question.
Do you have many new tiny purple or red spots (petechiae) or bruises without other symptoms?
If you have answered "No" to the above questions, go back to Check Your Symptoms and continue to answer the questions to evaluate your symptoms.
Do you have a rash with a fever?
See significance of a rash with a fever if you need information to help you answer the questions below.
Review health risks that may increase the seriousness of your symptoms.
| Note: |
If you need information on how to take a temperature, see the topic Body Temperature. |
Call your health professional immediately if you answer "Yes" to any of the following questions.
Do you have a fever of 104° (40°) or higher?
Do you think that you have a high fever but you are not able to measure your temperature?
Do you have a fever and any signs of a serious illness?
Have you developed a rash that looks like a sunburn within 2 days of the beginning of a fever greater than 102° (39°)?
Have you developed a rash that looks like a sunburn within 2 days of beginning a suspected moderate fever but you are not able to measure your temperature?
Call your health professional today if you answer "Yes" to the following question.
Do you know or think you have a fever?
If you have answered "No" to the above questions, go back to Check Your Symptoms and continue to answer the questions to evaluate your symptoms.
Do you have a generalized rash?
See significance of a generalized rash if you need information to help you answer the questions below.
Review health risks that may increase the seriousness of your symptoms.
Call your health professional immediately if you answer "Yes" to any of the following questions.
Do you have a red rash that peels skin away, leaving very large areas of tissue that weep or ooze fluid?
Have you developed a rash that looks like a sunburn within 2 days of the beginning of a fever greater than 102° (39°)?
Have you developed a rash that looks like a sunburn and you think you have a moderate fever, but you are unable to measure your temperature?
Call your health professional today if you answer "Yes" to the following question.
Is your rash painful?
You need an appointment within the next 1 to 2 weeks if you answer "Yes" to the following question.
Do you have a rash that has not gotten better after 2 weeks?
If you have answered "No" to the above questions, go back to Check Your Symptoms and continue to answer the questions to evaluate your symptoms.
See significance of a rash caused by a medicine if you need information to help you answer the questions below.
Review health risks that may increase the seriousness of your symptoms.
Call your health professional immediately if you answer "Yes" to any of the following questions.
Has swelling in your mouth or throat appeared within the past 1 to 3 hours but you do not have trouble breathing?
Call your health professional today if you answer "Yes" to the following question.
Do you think your rash may be caused by a medicine?
| Note: |
If your answer is Yes:
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If you have answered "No" to the above questions, go back to Check Your Symptoms and continue to answer the questions to evaluate your symptoms.
Do you have a rash and signs of a skin infection?
See significance of a rash and signs of infection if you need information to help you answer the questions below.
Review health risks that may increase the seriousness of your symptoms.
Call your health professional immediately if you answer "Yes" to any of the following questions.
Do you have diabetes?
Do you have peripheral arterial disease?
Do you have a disease or take medicine that causes problems with your immune system?
Call your health professional today if you answer "Yes" to any of the following questions.
Do you have increased pain, swelling, redness, or warmth around the rash?
Is the area around your rash more tender to the touch?
Do you have red streaks spreading from the rash?
Do you have pus in or around the rash?
Do you know or think you have a fever?
Do you have a rash with honey-colored drainage which dries into crusts and covers an area larger than 2 in. (5.1 cm)?
You may wait to see if the symptoms improve over the next 24 hours (or specified time period) if you answer "Yes" to any of the following questions.
Have you had mild pain and swelling with redness less than 1 in. (2.5 cm) around the rash for longer than 24 hours?
Have you had swollen glands (lymph nodes) in the neck, armpit, or groin for longer than 72 hours?
If you have answered "No" to the above questions, go back to Check Your Symptoms and continue to answer the questions to evaluate your symptoms.
Do you have a localized rash in one area of the body?
See significance of a localized rash if you need information to help you answer the questions below.
Review health risks that may increase the seriousness of your symptoms.
Call your health professional today if you answer "Yes" to any of the following questions.
Do you have painful blisters in a band around one side of the chest, abdomen, or face or down one arm or leg?
| Note: |
Call your doctor as soon as possible. If shingles is causing your symptoms, there may be a medicine you can take that will relieve the pain and limit the rash. Medicines are most effective if begun within 2 to 3 days of the start of the rash. |
Are you sexually active and you have a rash or sore in the genital area?
| Note: |
If you think that you have been exposed to a sexually transmitted disease (STD), it is important to be checked right away by your doctor. This will help prevent serious health problems for you and will lower the chance of spreading the infection to others.
Many STD symptoms will go away or change quickly. This does not mean that the STD has gone away. It will be harder for your doctor to diagnose your STD after the symptoms have changed. A delay in being checked may lead to a more serious problem. |
You need an appointment within the next 1 to 2 weeks if you answer "Yes" to any of the following questions.
Have you had a skin sore or ulcer for longer than 1 week?
Do you have a rash that has not improved after 2 weeks?
Do you have a mild rash that has lasted longer than 4 weeks?
Is a rash that has been checked by a doctor not following the expected course?
If you have answered "No" to the above questions, go back to Check Your Symptoms and continue to answer the questions to evaluate your symptoms.
See significance of itching if you need information to help you answer the questions below.
Review health risks that may increase the seriousness of your symptoms.
Call your health professional today if you answer "Yes" to any of the following questions.
Do you have a painful rash with severe itching?
Is severe itching stopping your usual activities or preventing sleep even after 12 hours of home treatment?
Do you have new patches of itchy, oozing rash?
You may wait to see if the symptoms improve over the next 24 hours (or specified time period) if you answer "Yes" to any of the following questions.
Do you have moderate itching after 48 hours of home treatment?
Do you have moderate to mild itching that has not gotten better after 1 week of home treatment?
You need an appointment within the next 1 to 2 weeks if you answer "Yes" to any of the following questions.
Have you had itching for longer than 4 weeks?
Do you have patches of itchy rash that have not been checked by a doctor or have gotten worse since being checked?
If you have answered "No" to the above questions, go back to Check Your Symptoms and continue to answer the questions to evaluate your symptoms.
Other Symptoms to Watch For
Do you have any of the following symptoms?
- Joint pain and swelling: Go to the topic Arm Problems, Noninjury or Leg Problems, Noninjury.
- Fever and a sore throat: Go the topic Sore Throat.
- A rash that looks like blisters: Go the topic Blisters.
- A scalp problem: Go the topic Scalp Problems.
- A sore near the mouth or on the lip: Go the topic Mouth Problems, Noninjury.
- A red, painful, or swollen bump under the skin: Go the topic Swollen Glands and Other Lumps Under the Skin.
- Skin changes: Go the topic Skin Changes.
- A sore in the genital area: Go the topic Exposure to Sexually Transmitted Diseases.
- Cracked, blistered, itchy, peeling skin between the toes: Go the topic Toe, Foot, and Ankle Problems, Noninjury.
If a visit to a health professional is not needed immediately, see the Home Treatment section for self-care information.
Home Treatment
Most rashes will go away without medical treatment. Home treatment can often relieve pain and itching until the rash goes away.
If you have come in contact with a substance such as poison ivy, oak, or sumac, immediately wash the area with large amounts of water.
Once a rash has developed, leave it alone as much as possible.
- Use soap and water sparingly.
- Leave the rash exposed to the air whenever possible.
- Do not scratch the rash.
If you have a rash, you should not be in contact with children or pregnant women. Most viral illnesses that cause a rash are contagious, especially if a fever is present.
Relief from itching
- Keep the itchy area cool and moist. Put cloths soaked in ice water on the rash a few times a day. Too much wetting and drying will dry the skin, which can increase itching.
- Keep cool and stay out of the sun. Heat makes itching worse.
- Try an oatmeal bath to help relieve itching. Wrap 1 cup of oatmeal in a cotton cloth or sock and boil as you would to cook it. Allow it to cool to room temperature, and use it as a sponge and bathe in cool water without soap. You may also buy a product at the store, such as Aveeno Colloidal Oatmeal bath.
- Avoid scratching as much as possible. Scratching leads to more scratching. Cut nails short or wear cotton gloves at night to prevent scratching.
- Wear cotton clothing. Do not wear wool and synthetic fabrics next to your skin.
- Use gentle soaps, such as Basis, Cetaphil, Dove, or Oil of Olay, and use as little soap as possible. Do not use deodorant soaps.
- Wash your clothes with a mild soap, such as CheerFree or Ecover, rather than a detergent. Rinse twice to remove all traces of the soap. Do not use strong detergents.
- Do not let the skin become too dry which may make itching worse. See the topic Dry Skin and Itching in Related Information for additional home treatment.
- Take several breaks during the day to do a relaxation exercise, particularly before going to bed if stress appears to cause your itching or make it worse. Sit or lie down, and try to clear your mind. Concentrate on relaxing every muscle in your body, starting with your toes and going up to your head. For more information, see the topic Stress Management.
Nonprescription medicines for itching
Carefully read and follow all label directions on the medicine bottle or box.
- Try calamine lotion for a rash caused by contact dermatitis, such as poison ivy or poison oak rashes.
- For severe itching, apply 1% hydrocortisone cream 4 times a day until the itch is gone.
- Try an oral antihistamine to help the scratch-itch cycle. Examples include chlorpheniramine maleate, such as Chlor-Trimeton, and diphenhydramine, such as Benadryl. Oral antihistamines are helpful when itching and discomfort are preventing you from doing normal activities, such as work and sleep. Antihistamines may cause drowsiness. Do not drive or operate any type of equipment if you are taking any of these medicines.
| Try a nonprescription medicine to help treat your fever or pain: |
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| Be sure to follow these safety tips when you use a nonprescription medicine: |
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Symptoms to Watch For During Home Treatment
Use the Check Your Symptoms section to evaluate your symptoms if any of the following occur during home treatment.
- A rash does not go away or gets worse even with home treatment.
- Symptoms become so bad that you are very uncomfortable.
- Other symptoms, such as a fever, feeling ill, or signs of infection, are severe or become worse.
- A new rash lasts longer than 2 weeks.
- A rash that has been diagnosed lasts longer than 4 weeks or is not following the expected course.
- Symptoms become more severe or more often.
Prevention
If you have a known allergy, avoid contact with the substance that causes the allergy.
Avoid infectious diseases that may cause skin rashes, such as sexually transmitted diseases (STDs). See the topic Exposure to Sexually Transmitted Diseases.
Treat your skin gently:
- Do not bathe too much. Soap and water dries your skin of the essential oils that hold in moisture.
- Do not scratch your skin or rub it roughly with towels.
- Avoid exposure to chemicals that may irritate the skin, such as rubbing alcohol, soaps, detergents, or solvents.
Preparing For Your Appointment
To prepare for your appointment, see the topic Making the Most of Your Appointment
You can help your doctor diagnose and treat your condition by being prepared to answer the following questions:
- What is the history of your rash, including:
- When did the rash start?
- Where did the rash start?
- Has the rash spread?
- Has the rash changed?
- Have you been in contact with anything that may have caused the rash?
- Have you been around anyone recently who has a similar rash?
- Have you had this rash before? If yes:
- What were the circumstances?
- When did you last have it?
- How was it treated?
- How long did it last?
- What other symptoms have you had? Symptoms may include itching, burning, stinging, tingling, numbness, pain, or tenderness to the touch.
- Have you used a new food, medicine, or product, such as cosmetics, cleaning agents, detergents, soaps, chemicals, fabrics, lotions, or nonprescription medicines?
- Have you been exposed to poisonous plants. such as poison ivy, oak, or sumac?
- Have you had any other health problems during the past 3 months?
- Have you recently traveled to a rural area or to another country?
- Have you been under an unusual amount of stress at home, work, or both?
- Does anyone in your family have a skin disorder or an allergy? If so, to what?
- What home treatment measures have you used? Has anything made the rash better or worse? Be sure to include any nonprescription medicines you have taken.
- Do you have any health risks?
Related Information
- Acne Vulgaris
- Allergic Reaction
- Athlete's Foot
- Atopic Dermatitis
- Blisters
- Chickenpox (Varicella)
- Diaper Rash
- Dry Skin and Itching
- Exposure to Sexually Transmitted Diseases
- Fever, Age 3 and Younger
- Fever, Age 4 and Older
- Fifth Disease
- Genital Herpes
- Genital Warts (Human Papillomavirus)
- Immunizations
- Insect Bites and Stings and Spider Bites
- Lice
- Lupus (Systemic Lupus Erythematosus)
- Lyme Disease
- Measles (Rubeola)
- Psoriasis
- Ringworm of the Scalp or Beard
- Ringworm of the Skin
- Rubella (German Measles)
- Scabies
- Scalp Problems
- Shingles
- Skin Cancer, Melanoma
- Stress Management
- Sunburn
- Swollen Glands and Other Lumps Under the Skin
- Tick Bites
- Toe, Foot, and Ankle Problems, Noninjury
- Warts and Plantar Warts
Credits
| Author | Jan Nissl, RN, BS |
| Editor | Susan Van Houten, RN, BSN, MBA |
| Associate Editor | Tracy Landauer |
| Primary Medical Reviewer | William M. Green, MD - Emergency Medicine |
| Specialist Medical Reviewer | Alexander H. Murray, MD, FRCPC - Dermatology |
| Last Updated | August 29, 2006 |
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