What Causes Rashes?
Rashes are one of the most common reasons that parents of small children visit the doctor. In most cases rashes do not indicate a dangerous condition, but in some cases they do. If a child is in good general health and has no other symptoms, you can simply observe the rash for a few days. Many types of rashes will disappear without treatment. If the rash is accompanied by high fever, breathing difficulties, vomiting, or reduced general health (when the child is not acting right), take your child to see a doctor, as it is often difficult to describe rashes over the telephone. One type of rash can have different causes, so let the doctor note what the rash looks like, how widespread it is, how many and how big the marks are, how long the rash has been present, and whether it is itchy.
Rashes Caused By Allergies
The most common allergic rash is hives, an extremely itchy rash that consists of raised large welts on the surface of the body, often circular with a pale center. Hives can result from an allergic reaction to medicines, foods, viral infections, or insect stings and bites. The rash moves around the body and usually lasts for three to four days before disappearing. Localized hives usually indicates direct skin contact with a substance that the person isn't able to tolerate, such as plants, pollen, or foods.
Localized Infections With Rashes
An infected wound occurs when a minor wound from a skin irritation, scratch, cut, or bite becomes infected by bacteria on the surface of the skin, on the mucous membranes, or from external sources. The wound becomes red and moist, pus and yellowish scabs appear, and the surrounding skin becomes swollen and tender because of inflammation. A child's lymphatic nodes may become swollen in the surrounding area and a fever may develop. If the child scratches the wound, bacteria may spread on the skin and give rise to more sores.
Impetigo can occur on any part of the body that has a wound or break in the skin. A rash usually results from a scratch, bite, or minor irritation that has become infected with streptococcus or staphylococcus bacteria. The wound becomes red and moist, with pus and eventually yellowish scabs. If a child scratches the wound, the bacteria may spread on the skin and cause more sores that develop over the course of a few days and last four to six days before drying up and forming scabs. It is usually treated with topical or oral antibiotics.
Cellulitis is a localized skin infection caused by streptococcus bacteria. The skin becomes swollen, hot, and red in one area that is clearly delineated from healthy skin. Often, there is no obvious entry point in the skin for the bacteria. Sometimes it can be accompanied by fever and a reduced general condition. Cellulitis should be evaluated and treated promptly, as the infection may spread rapidly.
Fungal rashes are skin infections caused by two specific types of fungi: tinea and candida. Tinea infections, also known as ringworm, are oval or ring-shaped lesions with normal-looking skin in the middle and an itchy, scaly, and slightly raised edge around it. The rash can be found on the scalp, face, body, or nails. Candida infections may occur in babies as oral thrush, as a white coating on the tongue or mouth mucosa or as a shiny, red rash in the diaper region (infected diaper rash). Candida infections may occur in children of any age. They are usually located in the folds of moist skin, such as under a baby's chin or the cracked skin between toes, accompanied by itching and sometimes nail discoloration (athlete's foot).
Scabies is a skin infection caused by the itch mite. The female mite burrows into the skin -- between the fingers, in the wrist area, and in the armpit. Babies can get scabies on the palms of their hands and soles of their feet. Scabies cause intense itching, which can lead to the formation of sores, blisters, scabs, and the possibility of secondary bacterial infection. Occasionally, it is possible to observe tiny gray burrows in the skin, made by the mite. Scabies is quite contagious, so prompt treatment by your physician is recommended.
Lice are insects that lay eggs while attached to the hairs of the head. The eggs hatch after approximately one week and cause itching on the scalp. Lice are commonly found on the hairline, on the neck, and behind the ears, and they can be seen using a magnifying glass and lice comb. Although lice are quite contagious, it is important to remember that they do not cause disease and will not make children sick. Proper treatment will prevent the spread of lice to other children.
Warts are a common childhood viral skin disease. There are several types and they can be found either individually or in clusters, usually on the fingers, hands, and feet. Most warts have a hard, rough surface and are slightly raised on the skin surface, but those on the sole of the foot (plantar warts) are pressed flat by body weight. Warts tend to disappear on their own without treatment, but they may return; plantar warts often require treatment.
Molluscum contagiosum is another common childhood rash, caused by a virus. The rash takes the form of tiny, raised bumps ("mollusks") on the skin surface that are 2 to 5 mm in diameter. The color ranges from pale, red flesh color to grayish white or yellow. Each bump has a little dent in the center. They usually do not bother the child, but they may be tender or itchy, so the child may tear and infect the skin by scratching. The "mollusks" can be found all over the child's body, individually or in clusters. Usually, they disappear without treatment after a few weeks or they may persist for several months or years. Treatment is not usually recommended.
There are three common types of eczema:
- Atopic dermatitis is chronic skin rash that affects children in families with a history of allergies. The rash is usually dry and itchy; the skin becomes red, irritated, and scaly. Scratching may lead to breaks in the skin, with resultant secondary infection and scarring.
- Seborrhea is also known as seborrheic dermatitis; it affects children under age 2 but usually infants up to 3 months. The cause is unknown, but it is thought to be a disturbance in the skin's production of sebaceous matter and sweat. Unlike atopic eczema, the rash is not particularly itchy and is dry, red, and slightly flaky. Seborrhea is usually localized to the face, neck, chest, folds of skin, and the diaper area. Infants may develop yellowish scabs on the scalp, called cradle cap. This rash generally disappears after a few months.
- Contact dermatitis occurs when certain substances, such as nickel, cosmetics, creams, and detergents, irritate the skin and cause a hypersensitivity reaction. The skin becomes red and angry-looking, occasionally giving rise to raised papules or vesicles in the affected areas of skin. The rash is often itchy but may also be moist, with blisters. Poison ivy is an example of a contact dermatitis.
Diaper rash occurs in the diaper area when the skin becomes moist, red, and irritated because of urine and stool. This irritation can cause tiny openings in the skin, which allow bacteria or fungi to invade and cause a secondary infection that makes the rash worse.
General Infections with Widespread Rashes
Rubella and Measles
In addition to a generalized rash of small, flat red spots, symptoms of the rubella and measles viruses include fever, malaise, and cough. Rubella and measles have become rare diseases in the U.S. because most children are vaccinated against the viruses at 15 months and then again between the ages of 4 and 6. Even though rubella has been totally eliminated from the U.S., immunization still continues because there is rubella in other countries.
The chicken pox (varicella) rash begins as red marks on the face and body that resemble mosquito bites. Within a few hours, the marks develop into fluid-filled blisters that later burst and leave scabs. Chicken pox is easily recognized because the skin around the vesicles is normal. Other symptoms include a fever, congestion, and blisters in the mouth. Because the rash is extremely itchy, it's best to prevent the child from excessive scratching, as there is a danger of bacterial infection in the skin, which can spread to other organs. Bacterial infections can also lead to wounds and scars. Chicken pox is quite contagious, and it is common for a number of children, at home or day care, to have it at the same time. After five to seven days, all the pox will be dry scabs, which means the child is no longer contagious. Most children in the U.S. now receive the chicken pox vaccine.
Scarlet fever is caused by a streptococcal infection of the throat. Symptoms include a sore throat, a high fever, and a rash that begins on the neck and face but then spreads down through the body. The skin reddens and there are small, sandpapery bumps. The area around the mouth is often spared and appears pale. After five to six days, the rash disappears and the child's skin often begins to peel, especially on the fingertips. If your child has scarlet fever, consult a physician to be tested for strep throat and treated with antibiotics.
Mononucleosis, often called mono, is a viral infection that often affects school-age children and adolescents. Symptoms include a sore throat, considerable difficulty swallowing, fever, and enlarged lymph nodes in the neck. The rash is nonspecific, pink, and prominent on the torso.
Roseola is a viral disease that results in a very high fever, which lasts three to four days with few other symptoms. The fever then drops suddenly and, within a few hours, a rash appears. The rash is nonspecific, pale pink, and mostly widespread on the neck and chest. It is not itchy, fades when pressure is applied, and disappears within one to two days. Typically, a child with roseola will be crankier when the rash appears than during the fever.
Fifth disease is another viral disease that begins with mild cold symptoms and fever. The rash appears after only one week, and significant redness on the cheeks and paleness around the mouth give the appearance of a slapped cheek. With some children, the rash spreads down the body, but the palms of the hands and the soles of the feet are often not affected. The rash can have a lacy appearance, might be itchy, and usually lasts one to three weeks.
Hand-foot-mouth disease is caused by the coxsackie virus, which produces little vesicles, or blisters, in the mouth, on the fingers, or on the feet. It is commonly seen in children under age 4, and symptoms include fever along with blisters in the mouth that make it difficult to eat. The disease normally runs its course over a few days, but the sores in the mouth can last longer. Children can get this illness more than once.
Lyme disease is caused by an infection transmitted through a tick bite. A rash usually appears two to six weeks after the tick bite, along with flulike symptoms (fever, headache, body pains). The rash usually appears as a red, circular area around the tick bite (there may be more than one), which spreads outward like a target. Lyme disease can also present without a rash and cause joint pains, chest pains, headaches, or neurological problems a few months later.
Acne is a common rash in teenagers and is a result of hair follicle blockage resulting from an increase in production of sebaceous matter in the skin. This will lead to localized inflammation of the skin, with red papules or fluid-filled pimples, called pustules. If not treated properly, acne may become severe, with cysts that can lead to scarring.
How to Prevent Rashes
- Avoid strong substances (soaps, detergents, perfumes) that may irritate the skin and make it more susceptible to injury and rashes. Avoid letting a child wear tight-fitting clothing that can irritate the skin.
- With eczema, dry skin is causing the itch. Frequent use of moisturizing creams and oil baths will soften the skin. Cut your child's nails short to prevent scratching injuries and skin damage. Certain foods can aggravate atopic eczema in children, so identify and avoid them if possible.
- Change diapers frequently and apply good general hygiene to prevent diaper rashes.
Treatment for Rashes
Treating rashes properly depends on a few factors: How is the child's general condition? Does the child have other symptoms or signs of illness? How quickly did the rash appear? Is it localized or is it generalized all over the body? How much does the rash bother your child? Is your child on any medications? Has your child been exposed to any new foods, soaps, or skin products?
For the most part, these are general ways to treat rashes:
- Bacterial skin infections should be treated with a topical antiseptic or antibacterial treatment. Topical treatment is usually sufficient, but oral antibiotics are sometimes necessary. If the lesions are extensive, or spreading, call your child's doctor.
- Give oral antihistamines (such as Children's Benadryl) to decrease the itch and the rash. Give antihistamines before bedtime because the medicine often makes children sleepy. Avoid antihistamine creams because they can irritate the skin and make the rash worse.
- Cool (not hot) baths with oatmeal will ease an itchy rash, and, after your child's bath, apply calamine lotion or a baking soda solution to the rash. For localized itchy rashes, apply 1% hydrocortisone cream if the rash is not a result of fungus, chicken pox, or bacterial infection.
- If your child has just started taking a new medicine, and develops a rash, consult your physician immediately.
Always contact 911 or the doctor immediately if your child:
- Has a high fever, headache, sore throat, or vomiting in addition to the rash.
- Has a rash close to the eyes or one that affects the eyes.
- Has a rash that has become infected with bacteria or fungi.
- Has eaten food or taken a new medicine before a rash developed.
- Has a fever as well as purplish patches or tiny red dots that do not blanch, which may be a sign of sepsis and meningitis.
- Has an intensely red rash that is very tender to the touch, which may be a sign of cellulitis.
- Has impetigo, which is commonly a secondary bacterial infection of the skin.
- Has the bullseye rash associated with Lyme disease.
- Has hives with simultaneous face swelling and breathing or swallowing difficulties, which may indicate an anaphylactic reaction.
- Has a rash that has persisted for more than three days, regardless of the cause.
Copyright 2012 Meredith Corporation.
All content on this Web site, including medical opinion and any other health-related information, is for informational purposes only and should not be considered to be a specific diagnosis or treatment plan for any individual situation. Use of this site and the information contained herein does not create a doctor-patient relationship. Always seek the direct advice of your own doctor in connection with any questions or issues you may have regarding your own health or the health of others.