Raised red bumps rash

22 Common Skin Rashes, Pictures, Causes & Treatment

A rash is any area of irritated or swollen skin on your body. Rashes are often itchy and painful and can appear differently on different skin tones. While they are often described as red, on darker skin tones they may be purple, gray, or white.

There are many different causes of rashes. Here’s a list of 22 potential causes with pictures.

Warning: graphic images ahead.

Fleabites

Share on PinterestFlea bites of the lower leg causing red bumps and scabbing. Angela Hampton Picture Library / Alamy Stock Photo

usually located in clusters on the lower legs and feet
itchy, small red bumps on lighter skin tones, and more plum-like in color on darker skin tones
symptoms begin immediately after being bitten

Read the full article on fleabites.

Fifth disease

Share on PinterestFifth disease is a viral illness caused by parvovirus, which can cause a ‘slapped cheek’ rash. Kardelen Yang?n Via Wikipedia

symptoms include headache, fatigue, low fever, sore throat, runny nose, diarrhea, and nausea
children are more likely than adults to experience a rash
round, bright red rash on the cheeks, but it may be less noticeable on darker skin tones
usually after the face rash, a lacy-patterned rash may appear on the arms, legs, and upper body and might be more visible after a hot shower or bath

Read the full article on fifth disease.

Rosacea

Share on PinterestWeinkle, A. P., Doktor, V., & Emer, J. (2015). Update on the management of rosacea. Clinical, cosmetic and investigational dermatology, 8, 159177. https://doi.org/10.2147/CCID.S58940

chronic (long-term) skin disease that goes through cycles of fading and relapse
relapses may be triggered by spicy foods, alcoholic beverages, sunlight, stress, and the intestinal bacteria Helicobacter pylori
the four subtypes of rosacea encompass a wide variety of symptoms
common symptoms include facial flushing, raised red bumps, facial redness, skin dryness, and skin sensitivity
on darker skin tones, brown or yellowish-brown bumps may appear, and the rash can have a dusky coloration

Read the full article on rosacea.

Impetigo

Share on PinterestThis image also depicts impetigo on dark skin. Photography courtesy of Grook Da Oger/Wikimedia

most common in children 2 to 5 years old, but can happen at any age
often located in the area around the mouth, chin, and nose
irritating rash and fluid-filled blisters that pop easily and form a honey-colored crust
can also appear brown, purple, or gray on darker skin tones

Read the full article on impetigo.

Ringworm

Share on PinterestRingworm on the face of a child. BSIP SA / Alamy Stock Photo

itchy, circular scaly patches with raised borders
on lighter skin tones, the patches can appear pink or red
on darker skin tones, the patches can appear gray or brown
skin in the middle of the ring appears clearer, and the edges of the ring may spread outward

Read the full article on ringworm.

Contact dermatitis

Share on PinterestContact dermatitis of the arm. vvoe/Shutterstock

appears hours to days after contact with an allergen
has visible borders and typically appears where your skin touched the irritating substance
on lighter skin tones, it can appear red
on darker skin tones, it may be less noticeable
may have blisters that weep, ooze, or become crusty
typically itchy, scaly, or raw

Read the full article on contact dermatitis.

Allergic eczema

Share on PinterestDmitriy SIMAKOV/Getty Images

may resemble a burn
often found on hands and forearms
skin is itchy, scaly, or raw
may have blisters that weep, ooze, or become crusty
on lighter skin tones, it can appear red
on darker skin tones, it can cause darker brown, purple, or gray patches

Read the full article on allergic eczema.

Hand, foot, and mouth disease

Share on PinterestHand-foot-and-mouth disease MidgleyDJ at en.wikipedia, CC BY-SA 3. 0, via Wikimedia Commons

usually affects children under age 5
painful, red blisters in the mouth and on the tongue and gums
flat or raised red spots located on the palms of the hands and soles of the feet
on darker skin tones, it can be skin-colored or grayish-brown
spots may also appear on the buttocks or genital area

Read the full article on hand, foot, and mouth disease.

Diaper rash

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located on areas that have contact with a diaper
skin looks red, wet, and slightly lighter or darker than typical skin color
may be warm to the touch

Read the full article on diaper rash.

Eczema

Share on PinterestBenislav/Shuttertstock

dry, rough, flaky, inflamed, and irritated skin
affected areas may be red and itchy
hair loss may occur in the area with the rash
on darker skin tones, it can appear as darker brown or gray patches

Read the full article on eczema.

Psoriasis

Share on PinterestPsoriasis is an inflammatory skin condition that causes dry, scaly plaques on the skin. It is immune system mediated, and genetics likely also play a role. Vitek2808/Shutterstock

scaly, silvery, sharply defined skin patches
on darker skin tones, it may look darker than the surrounding skin or it might appear purple
commonly located on the scalp, elbows, knees, and lower back
may be itchy or asymptomatic

Read the full article on psoriasis.

Chickenpox

Share on PinterestChild with chickenpox Grook da oger, CC BY-SA 4.0, via Wikimedia Commons

clusters of itchy, red, fluid-filled blisters in various stages of healing all over the body
on darker skin tones, it can be red, the same as the natural skin tone, or a little darker; scabs can appear gray
rash is accompanied by fever, body aches, sore throat, and loss of appetite
remains contagious until all blisters have crusted over

Read the full article on chickenpox.

Systemic lupus erythematosus (SLE)

Share on Pinterestbutterfly rash.SLE systemic lupus erythematosus

an autoimmune disease that displays a wide variety of symptoms and affects many body systems and organs
a wide array of skin and mucous membrane symptoms that range from rashes to ulcers
classic butterfly-shaped face rash that crosses from cheek to cheek over the nose
can appear bright red on lighter skin tones
on darker skin tones, it may appear red, brown, or darker than the original skin color
rashes may appear or get worse with sun exposure

Read the full article on systemic lupus erythematosus (SLE).

Share on Pinterestchatuphot/Shutterstock

painful rash that may burn, tingle, or itch, even if there are no blisters present
clusters of fluid-filled blisters that break easily and weep fluid
rash emerges in a band-like pattern that appears most commonly on the torso, but may occur on other parts of the body, including the face
may be accompanied by low fever, chills, headache, or fatigue

Read the full article on shingles.

Cellulitis

Share on PinterestCellulitis of the lower legs. TisforThan/Shutterstock

This condition is considered a medical emergency. Urgent care is required.

caused by bacteria or fungi entering through a crack or cut in the skin
tends to be red or pink
it may appear less obvious on darker skin tones and can also look brown, gray, or purple
painful, swollen skin with or without oozing that spreads quickly
hot and tender to the touch
might be a sign of serious infection requiring medical attention

Read the full article on cellulitis.

Drug allergy

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This condition is considered a medical emergency. Urgent care is required.

mild to severe itchy, red rash may occur days to weeks after taking a drug
severe drug allergies can be life threatening, and symptoms include rash, blisters, hives, racing heart, swelling, itching, and difficulty breathing
other symptoms include fever, stomach upset, and tiny purple or red dots on the skin

Read the full article on drug allergies.

Scabies

Share on PinterestScabies is an itchy skin infestation with mites. Public domain, via Wikimedia Commons

symptoms may take 2 to 5 weeks to appear
extremely itchy rash with small bumps that may be scaly
raised, white, or flesh-toned lines

Read the full article on scabies.

Measles

Share on PinterestMeasles on the torso of a child phichet chaiyabin/Shutterstock

symptoms include fever, sore throat, red watery eyes, loss of appetite, cough, and runny nose
depending on skin tone, the rash may be red, skin-colored, or darker than the natural skin color
the rash spreads from the face down the body 3 to 5 days after first symptoms appear
tiny white spots with bluish-white centers on a red background can appear inside the mouth

Read the full article on measles.

Tick bite

Share on PinterestAitor Diago/Getty Images

painless and causes only minor signs and symptoms, such as a change in skin color, swelling, or a sore on the skin
rash, burning sensation, or blisters
difficulty breathing, which requires immediate medical attention
the tick often remains attached to the skin for a long time
bites rarely appear in groups
may look like a target, circular, expanding — 70 to 80 percent of people with Lyme disease will have this rash

Read the full article on tick bites.

Seborrheic eczema

Share on PinterestZay Nyi Nyi/Shutterstock

yellow or white scaly patches that flake off
affected areas may be red — though they may appear faint on darker skin tones —, itchy, greasy, yellowish or white patches
hair loss may occur in the rash area

Read the full article on seborrheic eczema.

Scarlet fever

Share on PinterestChild with scarlet fever rash and rosy cheeks badobadop, CC BY-SA 3.0, via Wikimedia Commons

occurs at the same time as or right after a strep throat infection
rash is made up of tiny bumps that make it feel like “sandpaper”
bright red tongue
people with lighter skin tones can have a bright red rash all over the body (but not on the palms of your hands and soles of your feet)
on people with darker skin tones, it may be more difficult to see the rash, but their skin will have a sandpaper-like texture

Read the full article on scarlet fever.

Kawasaki disease

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This condition is considered a medical emergency. Urgent care is required.

usually affects children under age 5
red cracked lips, swollen tongue (strawberry tongue), high fever, swollen red palms and soles of the feet, swollen lymph nodes, bloodshot eyes
can be harder to recognize on darker skin tones
may cause severe heart problems

Read the full article on Kawasaki disease.

Contact dermatitis

Contact dermatitis is one of the most common causes of rashes. This type of rash occurs when the skin comes into direct contact with a foreign substance that causes an adverse reaction, leading to a rash. The resulting rash may be itchy, red, or inflamed.

Possible causes of contact dermatitis include:

beauty products
soaps
laundry detergent
dyes in clothing
chemicals in rubber, elastic, or latex
poisonous plants, such as poison oak, poison ivy, or poison sumac

Medications

Taking medications may also cause rashes. They can form as a result of:

an allergic reaction to the medication
a side effect of the medication
photosensitivity from the medication

Other causes

Other possible causes of rashes include the following:

A rash can sometimes develop in the area of a bug bite, such as a fleabite. Tick bites are of particular concern because they can transmit disease.
Atopic dermatitis, the most common form of eczema, is a rash that may be more common in people with asthma or allergies. The rash is often reddish, though it can be skin-colored or darker on people with darker skin tones. It can be itchy with a scaly texture.
Psoriasis is a common skin condition that can cause a scaly, itchy, red, or purplish rash to form along the scalp, elbows, and joints.
Seborrheic eczema is a type of eczema that most often affects the scalp and causes redness, scaly patches, and dandruff. It can also occur on the ears, brows, or nose. When babies have it, it’s known as cradle cap.
Systemic lupus erythematosus is an autoimmune disease that can trigger a rash on the cheeks and nose. This rash is known as a “butterfly,” or malar, rash.
Rosacea is a chronic skin condition of unknown cause. There are several types of rosacea, but all are characterized by redness and rash on the face.
Ringworm is a fungal infection that causes a distinctive ring-shaped rash. The same fungus that causes ringworm on the body and the scalp also causes jock itch and athlete’s foot.
Diaper rash is a common skin irritation in infants and toddlers. It can be associated with prolonged exposure to a wet diaper.
Scabies is an infestation by tiny mites that live on and burrow into your skin. It causes a bumpy, itchy rash.
Cellulitis is a bacterial infection of the skin. It usually appears as a red, swollen area that is painful and tender to the touch. If left untreated, the infection causing the cellulitis can spread and become life threatening.

Causes of rashes in children

Children are particularly prone to rashes that develop as a result of illnesses:

Chickenpox is caused by a virus, and the rash is characterized by small itchy bumps and blisters that form all over the body.
Measles is a viral respiratory infection that causes a widespread rash consisting of itchy, red bumps.
Scarlet fever is an infection due to group A Streptococcus bacteria that produces a toxin, causing a bright red or skin-tone-colored, sandpaper-like rash.
Hand, foot, and mouth disease is a viral infection that can cause red lesions on the mouth and a rash on the hands and feet.
Fifth disease is a viral infection that causes a red, flat rash on the torso, arms, and legs.
Kawasaki disease is a rare but serious illness that triggers a rash and fever in the early stages and can lead to heart complications.
Impetigo is a contagious bacterial infection that causes an itchy, crusty rash and yellow, fluid-filled sores on the affected area, such as the face, neck, or hands.

You can treat most contact rashes, but it depends on the cause. Follow these guidelines to help ease discomfort and speed up the healing process:

Use mild, gentle cleansers instead of scented bar soaps.
Use warm water instead of hot water for washing your skin and hair.
Pat the rash dry instead of rubbing it.
Let the rash breathe. If it’s possible, avoid covering it with clothing.
Stop using new cosmetics or lotions that may have triggered the rash.
Apply unscented moisturizing lotion to areas affected by eczema.
Avoid scratching the rash because doing so can make it worse and could lead to infection.
Apply an over-the-counter (OTC) hydrocortisone cream to the affected area if the rash is very itchy and causing discomfort. Calamine lotion can also help relieve rashes from chickenpox, poison ivy, or poison oak.
Take an oatmeal bath. This can soothe the itchiness associated with rashes from eczema or psoriasis. Here’s how to make an oatmeal bath.
Wash your hair and scalp regularly with dandruff shampoo if you have dandruff along with a rash. Medicated dandruff shampoo is commonly available at drugstores, but your doctor can prescribe stronger types if you need them.

Over-the-counter (OTC) medications

Talk with a healthcare professional, who may recommend OTC medication like ibuprofen or acetaminophen to treat mild pain associated with the rash.

Avoid taking these medications for an extended period because they can have side effects. Ask a healthcare professional how long it’s safe for you to take them. You may not be able to take them if you have liver or kidney disease or a history of stomach ulcers.

Call a healthcare professional if the rash doesn’t go away with home remedies. You should also contact them if you’re experiencing other symptoms in addition to your rash and you suspect you have an illness.

If you don’t already have a physician, you can use the Healthline FindCare tool to find a professional near you.

Go to the hospital immediately if you experience a rash along with any of the following symptoms:

increasing pain or discoloration in the rash area
tightness or itchiness in the throat
difficulty breathing
swelling of the face or limbs
fever of 100. 4°F (38°C) or higher
confusion
dizziness
severe head or neck pain
repeated vomiting or diarrhea

Contact a healthcare professional if you have a rash as well as other systemic symptoms, including:

joint pain
a sore throat
red streaks or tender areas near the rash
a recent tick bite or animal bite

Your healthcare professional will perform a physical exam and inspect your rash. Expect to answer questions about your:

rash
medical history
diet
recent use of products or medications
hygiene

Your healthcare professional may also:

take your temperature
order tests, such as an allergy test or complete blood count
perform a skin biopsy, which involves taking a small sample of skin tissue for analysis
refer you to a specialist, such as a dermatologist, for further evaluation

Your healthcare professional may also prescribe medication or medicated lotion to relieve your rash. Most people can treat their rashes effectively with medical treatments and home care.

Follow these tips if you have a rash:

Use home remedies to soothe mild contact rashes.
Identify potential triggers for the rash and avoid them as much as possible.
Call a healthcare professional if the rash doesn’t go away with home treatments. You should also contact them if you’re experiencing other symptoms in addition to your rash and you suspect you have an illness.
Carefully follow any treatments your doctor prescribes. Speak with a healthcare professional if your rash persists or gets worse despite treatment.

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Read the article in Spanish.

Rash on Hands and Feet: Common Causes and Treatment

Rashes are earmarked by a change in the color and texture of your skin. They may have blisters, and they may itch or hurt. Rashes that break out on your hands and feet have a wide range of underlying causes.

We’ll explore some of the common conditions that cause rashes to occur on the hands and feet. We’ll also look at treatment options you can try at home, or under a doctor’s care.

Common causes of rashes on the hands and feet	Overview
hand, foot, and mouth disease	contagious infection caused by several viruses, including the coxsackie virus
granuloma annulare	chronic, degenerative skin condition with an unknown cause
dyshidrotic eczema (dyshidrosis, pompholyx)	itchy, common form of eczema
impetigo	contagious, bacterial skin infection
hand-foot syndrome (acral erythema or palmar-plantar erythrodysesthesia)	side effect of certain chemotherapy drugs
athlete’s foot	contagious fungal infection

Rashes on the hands and feet can be caused by environmental factors, such as irritants or allergens. They may also be the result of medical conditions or infections.

Some common causes of rashes on hands and feet include:

Hand, foot, and mouth diseas

Hand, foot, and mouth disease is a contagious infection caused by several viruses, including the coxsackie virus. Anyone can get hand, foot, and mouth disease, although it most commonly occurs in babies and children.

This condition causes a rash on the hands and feet, as well as sores in the mouth and on the tongue. You may experience fever and a sore throat with this condition.

The hand and foot rash caused by this condition sometimes causes blistering to occur, and may be painful, but not itchy. In some instances, it may appear on the buttocks, as well.

Granuloma annulare

Granuloma annulare is a chronic, degenerative skin condition with an unknown cause. There are five recognized types:

localized granuloma annulare
generalized or disseminated granuloma annulare
subcutaneous granuloma annulare
perforating granuloma annulare
linear granuloma

The most common type, localized granuloma annulare, causes rings of flesh-toned, red, or yellow nodules to form on the feet, hands and fingers.

These nodules are small and hard, but do not typically itch. The rings usually clear up on their own without treatment, within a few months to two years. They may, however, come back.

Granuloma annulare is more common in women than in men, and tends to occur during young adulthood.

Dyshidrotic eczema (dyshidrosis, pompholyx)

This very itchy, common form of eczema causes deep-set blisters on the palms of hands, edges of fingers, soles and sides of feet, and toes. The blisters can become large and painful, and may last for several weeks.

Dyshidrotic eczema outbreaks often coincide with seasonal allergies, during spring and summer. It’s more common in women than in men. This condition is not curable, but its symptoms can be successfully treated. It’s not contagious.

Impetigo

This very contagious, bacterial skin infection begins with an oozing rash of red sores around the mouth and nose that can be spread to the hands and feet via touch. When the sores burst, they develop brownish-yellow crusts.

The rash can be itchy, and painful. Impetigo most commonly occurs in infants and children. Itching and soreness are other symptoms.

Hand-foot syndrome (acral erythema or palmar-plantar erythrodysesthesia)

This condition is a side effect of certain chemotherapy drugs used for cancer treatment. It’s earmarked by pain, swelling, and redness in either or both the palms of the hands and soles of the feet. It can also cause tingling, burning, and blisters. In severe cases, deeply cracked skin and extreme pain may occur.

Athlete’s foot

Athlete’s foot is caused by a contagious fungal infection. It usually starts between the toes, and spreads to the entire foot. This condition is earmarked by a scaly, red rash that itches.

In some instances, athlete’s foot can spread to the hands. This is more likely to happen if you pick at or scratch the rash on your feet.

Athlete’s foot is caused by keeping very sweaty feet trapped in shoes. It can also be transmitted on locker room and shower floors.

Many hand and foot rashes can be treated at home, but some require medical treatment, based on their underlying cause and severity.

There are a number of over-the-counter and at-home rash treatments that may help alleviate itching and pain, plus reduce the appearance of the rash. You may have the best success by combining several.

Home treatments include:

topical application of over-the-counter hydrocortisone cream
topical application of anti-itch medications containing pramoxine
topical application of lidocaine, or other types of pain medication
cold compresses
oral antihistamines
oral pain medication, such as acetaminophen or ibuprofen
cool oatmeal baths
applying unscented moisturizing cream
avoiding triggers, such as pollen

If you have dyshidrotic eczema: Avoid cobalt and nickel in food and in everyday items. Foods that contain cobalt include clams, fish, and leafy green vegetables. Foods that contain nickel include chocolate, soy beans, and oatmeal.

If you have impetigo: Cleaning and soaking the blisters and removing the crusts every few days may help. Cover the area with an antibiotic cream and loose dressing after treating.

If your rash does not clear up, your doctor may recommend the following:

corticosteroid injections
liquid nitrogen, applied directly to the rash to freeze the area and remove lesions
oral medication to reduce immune system reactions
light therapy using a laser
blister draining
antibiotics, if infection occurs

Any rash that’s painful, accompanied by fever, or looks infected should be seen by a doctor. You should also seek medical attention for a rash that doesn’t clear up easily with treatments you use at home.

Your doctor may be able to diagnose the rash visually after taking an oral history. In some instances, you may also expect diagnostic tests, such as:

skin culture
allergy tests
skin lesion biopsy

If your child has a rash that does not clear up within one or two days, they should be seen by their pediatrician. This will help determine the cause of the rash, and provide relief for their symptoms.

If your child has sores in their mouth or throat that prohibit them from drinking, they should also be seen by their doctor, to avoid complications such as dehydration.

Since conditions such as hand, foot, and mouth disease and impetigo are contagious, make sure to wash your hands after caring for your child.

If you’re a cancer patient experiencing hand-foot syndrome, let your doctor know. Your doctor may be able to change the dosage or type of medication you’re taking.

Rashes on the hands and feet can be caused by a wide range of conditions. These types of rashes sometimes clear up on their own, or they are treated easily at home.

Depending on their underlying conditions, some rashes will respond better to treatments performed or prescribed by a doctor. See your healthcare provider for any rash that’s accompanied by fever or pain.

Allergic rash - urticaria | Symptoms

Drugs, contrast agents (used in imaging studies such as computed tomography)
Signs: Allergic rash that begins within 48 hours after using the drug.

Emotional and physical stimuli (stress and anxiety, cold, exercise, skin pressure, heat, sunlight, sweating)
Signs: Allergic rash, which usually begins within seconds or minutes after contact with an irritant; an allergic rash that starts within 4 to 6 hours and affects only the area of skin where pressure has been applied, or an allergic rash that only affects the area of skin exposed to sunlight. nine0006

Food (food allergens)
Signs: Allergic rash that starts within minutes or hours of consumption.

Infections (bacterial, parasitic, viral)
Signs: Fever, chills, and fatigue. Specific infection symptoms, particularly for parasitic infections, recent travel to a developing country.

Insect bites or burns
Signs: Allergic rash that starts within seconds or minutes of an insect bite or burn. nine0006

Serum sickness
Signs: Allergic rash that begins within 7 to 10 days after an injection of a blood product (as in a transfusion), a drug derived from the blood of animals (used to treat venomous snake and spider bites). May be accompanied by fever, joint pain, swollen lymph nodes, and abdominal pain.

Contact allergens (latex, animal saliva or dander, dust, pollen or mold)
Signs: An allergic rash that begins within minutes or hours of contact.

Transfusion reactions
Signs: Allergic rash that usually starts within minutes of a blood product transfusion.

Systemic lupus erythematosus
Signs: Various symptoms depending on the autoimmune disease. With systemic lupus erythematosus, symptoms may include fever, fatigue, headache, joint pain and swelling, pain when breathing, and mouth ulcers. nine0006

Sjögren's syndrome
Signs: Dry eyes and dry mouth.

Urticarial vasculitis
Signs: An allergic rash that may be painful but not itchy. Usually lasts more than 24 hours. Does not whiten (brighten) when pressure is applied. May be accompanied by the formation of small blisters and red-violet spots (purpura).

Cancer (digestive or lung or lymphoma)
Signs: Weight loss, night sweats, abdominal pain, cough (sometimes with blood), jaundice, swollen lymph nodes, or a combination of these symptoms.

Chronic idiopathic allergic rash
Signs: Allergic rash that occurs almost daily and itching that lasts for 6 weeks with no apparent cause.

Endocrine disorders (thyroid disease or elevated progesterone)
Signs: For thyroid disorders: difficulty in tolerating heat or cold, slow or fast heart rate, and shaking (tremor) or slowness. Occurs in women who take birth control pills, undergo hormone therapy, or who have an allergic rash that appears before the onset of the menstrual period and disappears after it ends.

Mastocytosis
Signs: Small red bumps that turn into an allergic rash when touched. Sometimes abdominal pain, mild flushing, and recurring headaches. nine0006

Allergic rash (Urticaria; urticaria) - MRT Ministry of Health

Allergic rash

(Urticaria; urticaria)

Allergic rash is a red, itchy, slightly raised swelling. Itching may be severe. An allergic rash may have well-defined borders and a pale area in the center. As a rule, hives eruptions come and go. One nodule may persist for several hours, then disappear, and later another may appear elsewhere. After the nodule disappears, the skin usually looks completely normal. The swelling is caused by the release of chemicals (such as histamine) from mast cells in the skin, which cause fluid to temporarily leak from small blood vessels. nine0006

Angioedema

Allergic rash may develop with Quincke's edema, which, like an allergic rash, is accompanied by swelling. However, the swelling caused by angioedema is under the skin, not on its surface. Sometimes Quincke's edema affects the face, lips, throat, tongue, and airways. It can be life-threatening if the swelling interferes with breathing.

Causes of allergic rash

Urticaria and Quincke's edema are common allergic reactions. nine0006

Urticaria can be caused by inhaling, ingesting, squirting, or touching certain chemicals. These chemicals may be present in the environment, food, drugs, insects, plants, or other sources. For most people, they are harmless. However, if people are sensitive to them, these chemicals (called triggers or allergens) can trigger an allergic reaction. This means that the immune system reacts to chemicals. nine0006

However, urticaria is not always part of an allergic reaction. For example, it can occur as a result of autoimmune diseases. In these diseases, dysfunction of the immune system causes the body's own tissues to be misrecognised as foreign and attacked. In addition, some drugs directly cause hives without causing an allergic reaction. Emotional stress and certain physical stimuli (such as heat or light) can trigger hives for reasons that are not well understood. nine0006

Urticaria usually lasts less than 6 weeks and is classified as acute. If the urticaria lasts more than 6 weeks, then it is classified as chronic.

Acute urticaria most commonly caused by:

Allergic reactions are often caused by food, in particular eggs, fish, shellfish, nuts and fruits, or insect bites. Eating even small amounts of certain foods can suddenly cause hives. But when eating other foods (for example, strawberries), an allergic reaction occurs only after eating them in large quantities. Many medications, especially antibiotics, can cause hives. Immediate allergic reactions can also occur when a substance comes into direct contact with the skin (such as latex), after an insect bite, or as a reaction to a substance that is inhaled into the lungs or through the nose. nine0006

Non-allergic causes of allergic rashes include infections, certain drugs, certain physical stimuli (such as pressure or cold), some emotional stimuli (such as stress), and certain dietary supplements.

Although acute urticaria usually has specific causes, in half of the cases the cause cannot be identified.

Chronic urticaria most commonly caused by:

Sometimes the cause is easily overlooked, such as when people consistently consume a food that is not known to be the cause of the reaction (such as a preservative or dye in foods or penicillin in milk ). Often, despite best efforts, the cause remains unidentified. nine0006

Chronic urticaria can last from several months to several years, sometimes disappearing for no apparent reason.

Evaluation of allergic rash

Not every episode of urticaria requires immediate medical attention. The following information can help you decide if you need to see a doctor and what to expect when you see a doctor.

Warning signs

Some symptoms and characteristics are cause for concern:

Swelling of the face, lips, throat, tongue, or airways (angioedema)
Difficulty breathing, including wheezing
Urticaria that is intensely colored, with open sores, or lasting more than 48 hours
Fever, swollen lymph nodes, jaundice, weight loss and other symptoms of a general (systemic) illness

When to see a doctor

Need to call an ambulance if:

Need to go to the emergency room or doctor's office as soon as possible if:

Symptoms are severe.
The person feels increasing weakness or dizziness, or has a severe fever or chills.
The person develops vomiting or abdominal pain or diarrhea. nine0006

Seek medical attention if:

Bee sting causes urticaria (for treatment advice if another bee sting occurs).
The person has other symptoms such as fever, joint pain, weight loss, swollen lymph nodes or night sweats.
Urticaria recurs without exposure to a provocative factor. nine0006
Symptoms continue for more than 2 days.

If a child has urticaria that comes on suddenly, disappears quickly, and does not recur, a medical examination is usually not required. The cause is usually a viral infection.

What the doctor does

Doctors first ask questions about symptoms and medical history. Then they do a physical examination. Typically, a history and physical examination can identify a possible cause and determine what tests are needed. nine0006

Doctors ask the person to describe in detail each episode of hives and any other symptoms (eg, itching, difficulty breathing, or swelling of the face and tongue) that have occurred. They ask about the person's activities before and during the episode and possible exposure to substances that can cause allergic reactions, including medications they take. The person is also asked about specific symptoms that might indicate a cause, previous allergic reactions, and recent travel. nine0006

The precipitating factor cannot always be determined from the medical history (often because the precipitating factor is something that may have been transferred before).

During a physical examination, doctors first check for swelling of the lips, tongue, throat, or airways. In the presence of edema, treatment is started immediately. Doctors then pay attention to what the hives look like, determine which parts of the body are affected, and check for other symptoms that may help confirm the diagnosis. Doctors can use a variety of physical stimuli to see if they can trigger hives. For example, they may apply light pressure, heat and cold to the skin, or stroke the skin. nine0006

Testing

Generally, testing is not required for a single episode of urticaria unless symptoms indicate a specific disorder that requires treatment (eg, some infections). However, if the urticaria has unusual characteristics, recurs, or persists, investigations are usually done.

Tests typically include a complete blood count and blood tests to measure electrolytes, sugar (glucose), and thyroid-stimulating hormone levels and determine how well your kidneys and liver are functioning. Skin testing, such as a skin prick test, is done by an allergist (a doctor who specializes in allergic conditions) to identify specific allergens. Imaging studies and other blood tests are performed based on the results of the medical history and physical examination. If the results suggest that the cause is a disease that affects the whole body, then a thorough examination is necessary to identify it. nine0006

Skin biopsy is done if the diagnosis is unclear or if the rash persists for more than 48 hours.

Allergic rash treatment

Avoidance of triggers
Ways to relieve itching
Medicinal products

Urticaria often resolves without intervention in a day or two. If the cause is obvious, or if a doctor identifies a cause, people should avoid it if possible. If the cause is not obvious, people should stop taking all non-essential medications until the hives resolve. nine0006

Symptoms can be relieved by bathing and showering with cool water only, avoiding scratching and wearing loose clothing.

Medicines

For the treatment of allergic rashes, antihistamines are used for oral administration. These drugs partially relieve itching and reduce swelling. To achieve the effect, they should be taken regularly, and not as needed. Some antihistamines, including cetirizine, diphenhydramine, and loratadine, are available without a prescription. Diphenhydramine is the oldest drug that is more likely to cause drowsiness than the other two. Other antihistamines include desloratidine, fexofenadine, hydroxyzine, and levocetirizine. Creams and lotions containing antihistamines are generally not used because they can make the skin more sensitive and itch more

If symptoms are severe and other treatments fail, oral corticosteroids (such as prednisone) are used. They are taken for the shortest possible period of time. When taken by mouth for more than 3 to 4 weeks, corticosteroids cause many, including sometimes serious, unwanted effects (see Corticosteroid Uses and Side Effects). Corticosteroid creams do not help.

People admitted to the hospital with severe reactions or angioedema are given epinephrine . People with these severe reactions should have an epinephrine self-injection pen (epinephrine self-injection syringe) and should use it immediately if a reaction occurs.

About half of people with chronic urticaria go away without treatment within 2 years. In some adults, the antidepressant doxepin, which is also a powerful antihistamine, helps relieve chronic hives. Omalizumab, a monoclonal antibody, can be used in people with chronic allergic rashes that reappear despite other treatments. nine0006

Essential information for older people: Rashes

Older people are more likely to develop adverse effects when they take older antihistamines (eg hydroxyzine and diphenhydramine). In addition to drowsiness, these drugs can cause confusion and delirium, and can also cause difficulty starting and passing urine. Generally, older people should not take these drugs to relieve hives.