Content Map Terms
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 with the irritating substance (allergen). After 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.
- Jewellery 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 infections (STIs). 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.
Some medicines can cause a rash as a side effect. A very rare and serious type of generalized red rash called toxic epidermal necrolysis (TEN) may occur after using sulfa drugs. TEN can cause the skin to peel away, leaving large areas of tissue that weep or ooze fluid like a severe burn. TEN may occur after the use of some medicines. If this type of rash occurs, you need to see a doctor.
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.
Check your symptoms to decide if and when you should see a doctor.
Check Your Symptoms
The medical assessment of symptoms is based on the body parts you have.
- If you are transgender or non-binary, choose the sex that matches the body parts (such as ovaries, testes, prostate, breasts, penis, or vagina) you now have in the area where you are having symptoms.
- If your symptoms aren’t related to those organs, you can choose the gender you identify with.
- If you have some organs of both sexes, you may need to go through this triage tool twice (once as "male" and once as "female"). This will make sure that the tool asks the right questions for you.
Many things can affect how your body responds to a symptom and what kind of care you may need. These include:
- Your age. Babies and older adults tend to get sicker quicker.
- Your overall health. If you have a condition such as diabetes, HIV, cancer, or heart disease, you may need to pay closer attention to certain symptoms and seek care sooner.
- Medicines you take. Certain medicines, such as blood thinners (anticoagulants), medicines that suppress the immune system like steroids or chemotherapy, or natural health products can cause symptoms or make them worse.
- Recent health events, such as surgery or injury. These kinds of events can cause symptoms afterwards or make them more serious.
- Your health habits and lifestyle, such as eating and exercise habits, smoking, alcohol or drug use, sexual history, and travel.
Try Home Treatment
You have answered all the questions. Based on your answers, you may be able to take care of this problem at home.
- Try home treatment to relieve the symptoms.
- Call your doctor if symptoms get worse or you have any concerns (for example, if symptoms are not getting better as you would expect). You may need care sooner.
Sudden tiny red or purple spots or sudden bruising may be early symptoms of a serious illness or bleeding problem. There are two types.
Petechiae (say "puh-TEE-kee-eye"):
- Are tiny, flat red or purple spots in the skin or the lining of the mouth.
- Do not turn white when you press on them.
- Range from the size of a pinpoint to the size of a small pea and do not itch or cause pain.
- May spread over a large area of the body within a few hours.
- Are different than tiny, flat red spots or birthmarks that are present all the time.
Purpura (say "PURR-pyuh-ruh" or "PURR-puh-ruh"):
- Is sudden, severe bruising that occurs for no clear reason.
- May be in one area or all over.
- Is different than the bruising that happens after you bump into something.
If you're not sure if a fever is high, moderate, or mild, think about these issues:
With a high fever:
- You feel very hot.
- It is likely one of the highest fevers you've ever had. High fevers are not that common, especially in adults.
With a moderate fever:
- You feel warm or hot.
- You know you have a fever.
With a mild fever:
- You may feel a little warm.
- You think you might have a fever, but you're not sure.
Temperature varies a little depending on how you measure it. For adults and children age 12 and older, these are the ranges for high, moderate, and mild, according to how you took the temperature.
Oral (by mouth) temperature
- High: 40°C (104°F) and higher
- Moderate: 38°C (100.4°F) to 39.9°C (103.9°F)
- Mild: 37.9°C (100.3°F) and lower
A forehead (temporal) scanner is usually 0.3° C (0.5° F) to 0.6° C (1° F) lower than an oral temperature
- High: 40.5°C (104.9°F) and higher
- Moderate: 38.5°C (101.3°F) to 40.4°C (104.7°F)
- Mild: 38.5°C (101.3°F) and lower
Armpit (axillary) temperature
- High: 39.8°C (103.6°F) and higher
- Moderate: 37.8°C (100°F) to 39.7°C (103.5°F)
- Mild: 37.7°C (99.9°F) and lower
Certain health conditions and medicines weaken the immune system's ability to fight off infection and illness. Some examples in adults are:
- Diseases such as diabetes, cancer, heart disease, and HIV/AIDS.
- Long-term alcohol and drug problems.
- Steroid medicines, which may be used to treat a variety of conditions.
- Chemotherapy and radiation therapy for cancer.
- Other medicines used to treat autoimmune disease.
- Medicines taken after organ transplant.
- Not having a spleen.
Abnormal bleeding means any heavy or frequent bleeding or any bleeding that is not normal for you. Examples of abnormal bleeding include:
- Vaginal bleeding that is different (heavier, more frequent, at a different time of month) than what you are used to.
- Rectal bleeding and bloody stools.
- Bloody or pink urine.
- Gums that bleed easily when you eat or gently brush your teeth.
When you have abnormal bleeding in one area of your body, it's important to think about whether you have been bleeding anywhere else. This can be a symptom of a more serious health problem.
Symptoms of serious illness may include:
- A severe headache.
- A stiff neck.
- Mental changes, such as feeling confused or much less alert.
- Extreme fatigue (to the point where it's hard for you to function).
- Shaking chills.
Symptoms of infection may include:
- Increased pain, swelling, warmth, or redness in or around the area.
- Red streaks leading from the area.
- Pus draining from the area.
- A fever.
Shock is a life-threatening condition that may quickly occur after a sudden illness or injury.
Adults and older children often have several symptoms of shock. These include:
- Passing out (losing consciousness).
- Feeling very dizzy or light-headed, like you may pass out.
- Feeling very weak or having trouble standing.
- Not feeling alert or able to think clearly. You may be confused, restless, fearful, or unable to respond to questions.
Many prescription and non-prescription medicines can cause a rash. A few common examples are:
- ASA, ibuprofen (Advil, Motrin), and naproxen (Aleve).
- Pain medicines, such as codeine.
- Seizure medicines.
Symptoms of a severe allergic reaction can start within minutes of eating or being exposed to an allergen. While symptoms usually occur within 2 hours, in rare cases the time frame can vary up to several hours after exposure. Do not ignore early symptoms. When a reaction begins, it is important to respond right away.
Symptoms of a severe allergic reaction can vary from person to person. The same person can have different symptoms each time they have a severe allergic reaction. Symptoms can include any of the following:
- Skin: hives, swelling (face, lips, tongue), itching, warmth, redness
- Respiratory (breathing): coughing, wheezing, shortness of breath, chest pain or tightness, throat tightness, hoarse voice, nasal congestion or hay fever-like symptoms (runny, itchy nose and watery eyes, sneezing), trouble swallowing
- Gastrointestinal (stomach): nausea, pain or cramps, vomiting, diarrhea
- Cardiovascular (heart): paler than normal skin colour/blue colour, weak pulse, passing out, dizziness or lightheadedness, shock
- Other: anxiety, sense of doom (the feeling that something bad is about to happen), headache, uterine cramps, metallic taste
A severe reaction can take place without hives, so make sure to look out for all of the signs of an allergic reaction.
Adapted from: Anaphylaxis in Schools and Other Settings, Copyright 2005-2009 Canadian Society of Allergy and Clinical Immunology
Seek Care Today
Based on your answers, you may need care soon. The problem probably will not get better without medical care.
- Call your doctor today to discuss the symptoms and arrange for care.
- If you cannot reach your doctor or you don't have one, seek care today.
- If it is evening, watch the symptoms and seek care in the morning.
- If the symptoms get worse, seek care sooner.
Make an Appointment
Based on your answers, the problem may not improve without medical care.
- Make an appointment to see your doctor in the next 1 to 2 weeks.
- If appropriate, try home treatment while you are waiting for the appointment.
- If symptoms get worse or you have any concerns, call your doctor. You may need care sooner.
Seek Care Now
Based on your answers, you may need care right away. The problem is likely to get worse without medical care.
- Call your doctor now to discuss the symptoms and arrange for care.
- If you cannot reach your doctor or you don't have one, seek care in the next hour.
- You do not need to call an ambulance unless:
- You cannot travel safely either by driving yourself or by having someone else drive you.
- You are in an area where heavy traffic or other problems may slow you down.
Call 911 Now
Based on your answers, you need emergency care.
Call 911 or other emergency services now.
Sometimes people don't want to call 911. They may think that their symptoms aren't serious or that they can just get someone else to drive them. But based on your answers, the safest and quickest way for you to get the care you need is to call 911 for medical transport to the hospital.
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.
After 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.
- Add a handful of oatmeal (ground to a powder) to your bath. Or you can try an oatmeal bath product, such as Aveeno.
- 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 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.
- 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. Managing your stress by relaxing every muscle in your body, starting with your toes and going up to your head, may help your symptoms.
Non-prescription 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 from contact dermatitis, apply hydrocortisone cream 4 times a day. Do not use this cream on a fungal or bacterial rash, unless advised by your doctor. Hydrocortisone cream should not be used for longer than 7 to 10 days without talking with your doctor.
- Try an oral antihistamine to help the scratch-itch cycle. Examples include a non-drowsy one like loratadine (Claritin) or one that might make you sleepy like diphenhydramine (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. And don't give antihistamines to your child unless you've checked with the doctor first.
Try a non-prescription medicine to help treat your fever or pain:
Talk to your child's doctor before switching back and forth between doses of acetaminophen and ibuprofen. When you switch between two medicines, there is a chance your child will get too much medicine.
Be sure to follow these safety tips when you use a non-prescription medicine:
Symptoms to watch for during home treatment
Call your doctor if any of the following occur during home treatment:
- Other symptoms, such as a fever, feeling ill, or signs of infection, are severe or become worse.
- A rash lasts longer than 2 weeks.
- Symptoms become more severe or happen more often.
If you have a known allergy, avoid contact with the substance that causes the allergy.
Avoid all infectious diseases that cause skin rashes, such as chickenpox, measles, and some types of sexually transmitted infections (STIs).
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?
- Has anything made the rash better or worse?
- 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 non-prescription 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 travelled 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?
- Have you had an immunization (vaccine) shot recently?
- Do you have any symptoms of a sexually transmitted infection (STI)?
- What home treatment measures have you tried? Did they help?
- What non-prescription medicines have you tried? Did they help?
- Do you have any health risks?
Adaptation Date: 4/13/2022
Adapted By: HealthLink BC
Adaptation Reviewed By: HealthLink BC
Adaptation Date: 4/13/2022
Adapted By: HealthLink BC
Adaptation Reviewed By: HealthLink BC
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