Rashes are typically caused by a reaction to a pathogen. Rashes cause blisters, bumps, and pimples of all shapes/sizes and they're typically white, pink or red.
So you look like your favorite dotted Swiss comforter and it's two weeks before your long-distance flame is flying cross country to meet you. Great. Now what? What is causing this sudden rash and how can you get rid of it fast? Well, getting rid of a rash, like getting rid of any disease or condition, requires you to address the underlying causes.
Maybe you took a walk in the woods yesterday and then woke up in the middle of the night covered with the oozing blisters of poison ivy. Maybe you didn't know you were allergic to strawberries until after enjoying a strawberry shortcake dessert and suddenly breaking out in hives. The symptoms of rashes are quite obvious. Think of measles or poison ivy outbreaks.
Rashes are eruptions of pimples and blisters that can appear anywhere on the body. A rash may appear only on the spot where something you're allergic to has touched you, such as poison ivy. Or it may show up all over the body if you eat something you're allergic to, such as strawberries.
Common characteristics of rash are
Rashes cause blisters, bumps, and pimples of all shapes and sizes. Rashes are typically white, pink, or red and appear:
- Flat (even with the skin) or raised (elevated from the skin)
- Smooth or scaly
- Dry or oozing
- Red, inflamed, itchy, and painful
- Without any particular sensation at all
More about rash symptoms
Symptoms of a rash can also be described by their duration and severity.
- Acute: Lasting only a short time
- Chronic: Lingering for months or years
- Benign: Causing nothing more than worry and discomfort
- Serious: An indication of a serious underlying condition, such as cancer
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Rashes are typically caused by a reaction to some kind of pathogen — something that acts as an invader to the body because you are allergic to it. Because it is toxic to your body, your immune system goes to work on it as it would any invader, launching an inflammatory response and mobilizing your fighter cells for an attack.
Rashes can also be caused by fever and infection, be it a viral, bacterial, or fungal. The infection causes an inflammatory reaction in the body and the skin, causing the appearance of a rash.
The most common causes or rashes include the following.
- Inflammation: The itchy, scaly rash associated with eczema is caused by an underlying inflammatory condition. Inflammatory rashes may also result from external factors such as skin contact with a chemical irritant, including household cleaning products.
- Allergies: You probably won't know you have an allergy until the first time you have an allergic reaction. It could be the result of something you ate, something you touched, or a medication you were prescribed. Your body's response is the same — itchy welts appearing anywhere on your skin. Hives can last for minutes or for as long as several weeks.
- Non-specific dermatitis, skin inflammation, and non-specific skin rash: These are catch-all terms for a rash without a diagnosed cause. These conditions might be caused by an infection, by inflammation, or by an allergic reaction.
This list does not constitute medical advice and may not accurately represent what you have.
Non-specific skin rash
Common causes of rash are contact dermatitis, sun damage, or allergic reaction. However, many rashes are a symptom of disease and should not be ignored.
Nonspecific rashes have widely varied symptoms:
- May be flat and smooth; slightly raised or with swollen welts; clean and dry; or blistered and oozing.
May spread widely over the body, or be confined to one site.
- May appear after eating certain foods; or after exposure to certain plants or to insect stings or bites.
Other symptoms may be present, including pain anywhere in the body; nausea; vomiting; fever; headache; or abdominal pain and upset.
Diagnosis is made through patient history and physical examination to determine the exact type, location, and history of the rash, along with any other symptoms that may be present.
Those symptoms will be investigated with blood tests or imaging. Skin swabs may be taken and tested. After the process has ruled out as many causes as possible, a course of treatment can be determined.
Top Symptoms: rash
Symptoms that always occur with non-specific skin rash: rash
Urgency: Wait and watch
Non-specific dermatitis (skin inflammation)
Nonspecific dermatitis, or contact dermatitis, simply means inflammation of the skin from many different causes.
Most nonspecific dermatitis is caused by skin contact with a substance that provokes a reaction, which could be anything from plants to soap to jewelry to fabrics. Some may be due to an autoimmune condition, where the body's immune system attacks itself.
Risk factors include a family or personal history of allergies, asthma, or other condition which weakens the immune system; or constant contact with metals, plant life, or chemicals.
Symptoms commonly include red, swollen skin rash with itching, blistering, or oozing, which may become painful and infected.
Dermatitis itself is not contagious but can interfere with quality of life. A medical provider can help with managing the symptoms.
Diagnosis is made through patient history, physical examination, and sometimes skin biopsy and patch testing.
Treatment involves using protective measures if the substances cannot be avoided; making nutritional improvements to strengthen the immune system; using corticosteroid or other creams; and phototherapy.
Top Symptoms: red rash, itchy rash, painful rash
Symptoms that always occur with non-specific dermatitis (skin inflammation): red rash
Eczema (atopic dermatitis) is a non-contagious chronic skin condition that produces an itchy rash. It is caused by a genetic condition that affects the skin's ability to protect itself from bacteria and allergens. The most susceptible are those with a family hi..
Pityriasis rosea is a common skin rash and is thought to be due to a type of herpes virus. It is not contagious and is not sexually transmitted. Most susceptible are teenagers and young adults.
Symptoms include a single large scaly patch somewhere on the body. In the next 7 to 14 days similar oval pink patches on the arms, legs, and trunk appear, sometimes in a pattern of lines.
There may also be itching, fatigue, and body aches along with the rash. Anything that raises body temperature, such as exercising or a hot bath, may worsen the rash.
The condition may last for a few weeks and is normally gone after three to four months. Sometimes flat brown spots are left as the rash fades.
Pityriasis rosea can resemble other conditions, so getting an accurate diagnosis is important. Diagnosis is made through blood tests and skin cultures.
Treatment involves topical medications for itching, as well as antiviral and anti-inflammatory medications by mouth to aid healing. Cool baths and reduced exercise will also help.
Top Symptoms: rash, itchy rash, curved rash, rough patch with red spots around it
Symptoms that always occur with pityriasis rosea: rash
Symptoms that never occur with pityriasis rosea: blue-colored skin changes, black-colored skin changes, brown-colored skin changes
Psoriasis causes an overgrowth of surface skin cells, creating a red, scaly, itchy, and painful rash.
It is believed to be an autoimmune disorder that causes the body to attack its own healthy skin cells. It may be genetic in origin but triggered by anything that further strains the immune system, such as infections, skin injury, alcohol consumption, obesity, smoking, and stress.
Symptoms may come and go in cycles lasting weeks or months. They include red patches of thickened skin, sometimes with gray-white scales; dry, cracked, bleeding skin; stiff and swollen joints; and thickened, misshapen nails.
It is important to see a medical provider for care, because psoriasis can interfere with quality of life. It is associated with higher risk of arthritis, heart disease, diabetes, and other conditions.
Treatment involves different combinations of topical medications, oral medications, and phototherapy with natural or artificial light. Lifestyle changes such as improved diet, quitting smoking, and managing stress are very helpful in many cases.
Top Symptoms: itchy rash, red or pink, rough patch of skin, rash with well-defined border, painful rash, scaly rash
Symptoms that never occur with psoriasis: fever, black-colored skin changes, brown-colored skin changes, blue-colored skin changes
Urgency: Primary care doctor
Keratoacanthoma (a common, benign skin change)
Keratoacanthomas are rapidly growing lesions that occur primarily on sun-exposed skin in older persons. The majority of lesions involve the face and upper extremities, although they frequently occur on the lower extremities, especially in women.
Top Symptoms: itchy rash, rash on sun-exposed areas, red skin bump larger than 1/2 cm in diameter, skin-colored rash, skin-colored, large (>1/2 cm) bump
Symptoms that never occur with keratoacanthoma (a common, benign skin change): fever
Urgency: Wait and watch
Hives, or urticaria, are flat red welts that can appear anywhere on the skin and usually itch. Hives often occur as an allergic reaction to something eaten or something that has contacted the skin. Foods, medicines, and plants are common causes, but sun exposure, stress, infections, and autoimmune diseases have also been..
Irritant contact dermatitis
Irritant contact dermatitis means a skin reaction that is caused by directly touching an irritating substance, and not by an infectious agent such as a bacteria or virus.
Common causes are soap, bleach, cleaning agents, chemicals, and even water. Almost any substance can cause it with prolonged exposure. Contact dermatitis is not contagious.
Anyone who works with an irritating substance can contract the condition. Mechanics, beauticians, housekeepers, restaurant workers, and health care providers are all susceptible.
Symptoms include skin that feels swollen, stiff, and dry, and becomes cracked and blistered with painful open sores.
A medical provider can give the best advice on how to heal the skin and avoid further irritation. Self-treatment can make the problem worse if the wrong creams or ointments are used.
Diagnosis is made through patient history, to find out what substances the patient comes into contact with, and through physical examination of the damaged skin.
Treatment involves avoiding the irritating substance if possible. Otherwise, the person can use petroleum jelly on the hands underneath cotton and then rubber gloves.
Top Symptoms: rash with well-defined border, itchy rash, red or pink, rough patch of skin, painful rash, red rash
Symptoms that always occur with irritant contact dermatitis: rash with well-defined border
Symptoms that never occur with irritant contact dermatitis: fever, black-colored skin changes, brown-colored skin changes, blue-colored skin changes
Allergic reaction to poison ivy/oak/sumac
Plants of the Toxicodendron genus are found throughout the continental United States, and exposure to these plants is a leading cause of contact dermititis, a medical term used to describe irritation and itching of the skin.
Top Symptoms: rash, itchy rash, red rash, skin changes on arm, stinging or burning rash
Symptoms that always occur with allergic reaction to poison ivy/oak/sumac: itchy rash, rash
Symptoms that never occur with allergic reaction to poison ivy/oak/sumac: fever
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Rash treatments and relief
Many rashes can be treated at home. There is an old adage in dermatology: "If it's dry, wet it; if it's wet, dry it." This is not an absolute rule set in stone, but if you have a rash that does not seem to be causing other problems and you are not ready to see a healthcare provider, this is your best approach.
- Topical cortisone creams: If you have a wet type of rash, apply nothing — or try topical cortisone creams (available over-the-counter). These can also be used on dry rashes to relieve itching and prevent secondary infections which can be caused by scratching.
- Cold, wet compresses: These can also promote healing and provide relief from itch.
- Royal jelly: If you have a very dry rash, try natural emollient with compounds such as royal jelly in them. Royal jelly is all-natural and is particularly healing on rashes.
- Air and breathable clothing: The best approach to oozing, weeping, wet, or blistery rashes is to keep the area dry by exposing it to air and avoid covering the area with clothing that doesn't "breathe."
- Other topical methods: Applying witch hazel, apple cider vinegar, or a baking soda paste to the blisters will speed up the drying-out process.
If itching is interfering with sleep, you can try Benadryl, an anti-histamine. This over-the-counter medicine can ease the itching and help you get some much-needed rest after all that sleep-robbing itching.
When to see a doctor
If your rash worsens or persists, especially if you have tried the above at-home remedies, it's time to consult a physician. Being mindful of products you have used recently or foods you have eaten — especially if they're out the ordinary — can be very useful information to your provider as well.
When it is an emergency
Seek immediate medical care if you develop a rash and also have:
- A fever
- Flu-like symptoms
- Difficulty breathing
- Swelling on your face or lips
- Bleeding lesions
- Nausea, vomiting, or stomach pain
Not all rashes can be prevented, especially if you are unaware of certain sensitivities or allergies. However, you can keep rashes at bay by practicing good hygiene and maintaining a skincare routine made up of gentle or otherwise recommended products for your specific needs. When going outside or in areas with a lot of wildlife or plants, be sure to wear protective shoes and clothing.
FAQs about rash
What causes rashes?
Rashes are caused by local inflammation of the skin and are caused by multiple inflammation pathways. For example, seborrheic dermatitis (a rash involving yellow, oily flakes on the face or hair) is caused by overgrowth of a normal skin yeast. Contact dermatitis is caused by a hypersensitivity, or allergic reaction, of the skin to certain chemicals. This reaction happens when the cells of the skin present a non-dangerous chemical (e.g. cotton, nickel, wool) to the "central booking" cell CD4, CD8 cells which activate the immune system against the cells.
What causes rash on neck?
A rash on the neck can be caused by an exposure to something across the neck. Common causes of neck rashes include contact with metals such as the nickel included in some jewelry and contact with animal fur or wool, as well as excessive exposure to sunlight (sunburn). There is no specific cause of a rash on the neck that cannot also cause a rash on the face, abdomen, legs, or chest. It is important to recall what substances your neck has been exposed to (e.g. scarves, hair dyes, shirt collars, or sunlight) that might cause a rash along the neck.
What causes a heat rash?
A heat rash can occur when a person is sweating often. This rash looks like a series of closely spaced bumps or pimples and happens when the sweat does not evaporate as it should, especially if the person also has an innate sensitivity to sweat on the skin. Heat rash can be avoided by staying cool and dry. Taking cool baths and wearing loose clothes that allow your skin to breathe will be helpful.
What kind of rash do I have?
To have your rash correctly diagnosed, visit a health professional. They will ask you the following questions: What color is the rash? What areas of the body does it affect? Is it continuous, spotty,or blotchy? Is it pinpoint? Is it raised or flat? Are there any other skin changes around the rash such as flaking, bleeding, or pus? Is it painful? Do you have any other physical symptoms that appeared at about the same time as the rash?
What types of skin rashes itch?
Many different types of rashes can itch. Some disorders are related only to the skin, while others are related to the function of the liver, kidneys, thyroid, and connective tissue. The key to determining the type of rash lies in how long the rash has been present, where on the body it appears, what it looks like, what makes it better or worse, and what other medical conditions an individual has.
Questions your doctor may ask about rash
- Any fever today or during the last week?
- Is your rash raised or rough when you run your hand over the area of skin?
- What color is the skin change?
- Are there bumps on your rash?
Self-diagnose with our free Buoy Assistant if you answer yes on any of these questions.
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- Hives. Seattle Children's. Updated Nov. 3, 2018. Seattle Children's Link
- Kang JH. Febrile Illness with Skin Rashes. Infect Chemother. 2015;47(3):155-66. NCBI Link
- Rash or Redness - Widespread. Seattle Children's. Reviewed Jan. 29, 2019. Seattle Children's Link
- Yamaura K, Tomono A, Suwa E, Ueno K. Topical royal jelly alleviates symptoms of pruritus in a murine model of allergic contact dermatitis. Pharmacogn Mag. 2013;9(33):9-13. NCBI Link