Rashes

What Are Rashes?

Rashes are abnormal changes in skin color or texture. They usually result from skin inflammation, which can have many causes.

There are many types of rashes, including eczema, granuloma annulare, lichen planus, and pityriasis rosea.

Eczema

Eczema is a general term that describes several different conditions in which skin is inflamed, red, scaly, and itchy. Eczema is a common skin condition, and atopic dermatitis (also called atopic eczema) is one of the most common forms of eczema.

Eczema can affect adults or children. The condition isn’t contagious.

Causes

We don’t know for sure what causes atopic eczema, but the condition often affects people with a family history of allergies. If you have eczema, you may also have hay fever and/or asthma, or have family members with those conditions.

Some things can trigger a flare-up of eczema or make eczema worse, but they don’t cause the condition. Eczema triggers include stress, skin irritants (including soaps, skin care products, or some fabrics), allergens, and climate/environment.

Symptoms

The way eczema looks can vary from person to person. In adults, eczema most often affects the hands, elbows, and "bending" areas like the inside of the elbows and back of your knees. In young children, eczema often shows up inside the elbows, behind the knees, and on the face, back of the neck, and scalp. Signs and symptoms of atopic eczema include:

  • Itchiness
  • Skin redness
  • Dry, scaly, or crusted skin that might become thick and leathery from long-term scratching
  • Formation of small, fluid-filled blisters that might ooze when scratched
  • Infection of the areas of broken skin

Diagnosis

To diagnose atopic eczema, the doctor will check your skin and ask about your symptoms. They might test an area of scaly or crusty skin to rule out other skin diseases or infections.

Treatment

You can treat eczema with moisturizers that are fragrance-free and contain ingredients such as ceramides, glycerin, and mineral oil. Medications include over-the-counter creams and ointments containing the steroid hydrocortisone (for example, Cortizone-10, Cort-Aid, Dermarest Eczema, Neosporin Eczema). These products may help control the itching, swelling, and redness linked to eczema. Prescription-strength cortisone creams, as well as cortisone pills and shots, are also used for more severe cases.

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For people with mild to moderate eczema, topical immunomodulators (TIMs) can help. TIMS -- including brand name products Elidel and Protopic -- work by changing the body's immune response to allergens, preventing flare-ups.

Crisaborole (Eucrisa) is an ointment for mild to moderate psoriasis in those 2 and older.

Dupilumab (Dupixent) is an injectable monoclonal antibody used in patients with moderate to severe atopic dermatitis. It clears the itch quickly in most patients.

Other drugs that might be used for people with eczema include antibiotics (to treat infected skin) and antihistamines (to help control itching).

Phototherapy is another treatment that helps some people with eczema. The ultraviolet light waves found in sunlight have been shown to help treat certain skin disorders, including eczema. Phototherapy uses ultraviolet light -- either ultraviolet A (UVA) or ultraviolet B (UVB) -- from special lamps to treat people with severe eczema.

Risks linked to phototherapy include burning (usually resembling a mild sunburn), dry skin, itchy skin, freckling, and possible premature aging of the skin. Your health care professionals will work with you to lessen any risks.

Prevention

There’s no way to prevent atopic eczema, but you can do things to improve your symptoms:

  • Reduce stress
  • Avoid scratchy materials (for example, wool) and chemicals such as harsh soaps, detergents, and solvents
  • Moisturize often
  • Avoid sudden changes in temperature or humidity
  • Avoid situations that cause sweating and overheating

Granuloma Annulare

Granuloma annulare is a chronic skin condition that consists of a circular-shaped rash with reddish bumps (papules).

Most often, the condition affects children and young adults. Granuloma annulare is slightly more common in girls and usually is seen in people who are otherwise healthy.

Causes

We don’t know what causes granuloma annulare.

Symptoms

People who have granuloma annulare usually notice one or more rings of small, firm bumps over the backs of their forearms, hands, or feet. The rash may be mildly itchy.

Diagnosis

Your doctor can diagnose you. They might use a skin biopsy to confirm you have granuloma annulare.

Treatment

Treatment of granuloma annulare usually isn’t necessary, except for cosmetic reasons. In some cases, steroid creams or ointments can help the bumps disappear. Some doctors may decide to freeze the lesions with liquid nitrogen or to inject steroids directly into the rings of bumps. Ultraviolet light therapy or oral drugs can be used in serious cases.

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Lichen Planus

Lichen planus is a common skin disorder that produces shiny, flat-topped bumps. They often have an angular shape and a reddish-purplish color. Lichen planus can show up anywhere on the skin but often affects the insides of your wrists and ankles, your lower legs, your back, and your neck. Some people have lichen planus inside their mouth, genital region, scalp, and nails. Thick collections of bumps may occur, especially on the shins.

Lichen planus most often affects adults ages 30-70. It isn’t common in very young or elderly people.

Causes

Doctors think lichen planus is an autoimmune condition, meaning your body’s immune system attacks its own tissues. But they don’t know what causes it. Sometimes lichen planus results from a triggering agent such as hepatitis B or hepatitis C. Doctors call that a lichenoid reaction.

If you’re allergic to medications to treat high blood pressure, heart disease, and arthritis, you could get a lichen planus-type rash. Lichen planus isn’t contagious.

Symptoms

Signs and symptoms of the condition include shiny, flat-topped bumps that are purple or a reddish-purplish color. It’s often itchy. When it shows up on your scalp, lichen planus can lead to hair loss. Lichen planus of the nails can cause brittle or split nails.

Diagnosis

A doctor can diagnose lichen planus by the way it looks or with the use of a skin biopsy. For this procedure, they’ll take a small bit of skin from the affected area and send it to a lab for testing.

Treatment

Lichen planus can’t be cured, but you can treat the symptoms with anti-itch products like antihistamines (for example, Benadryl, or diphenhydramine). If lichen planus affects only a small part of the body, you can apply medicated cream to the affected area. In more severe cases, doctors might prescribe steroid shots, prednisone, or other drugs that suppress your immune system. They might also give you retinoids or try light therapy.

Pityriasis Rosea

Pityriasis rosea is a common skin rash that usually is mild. The condition often begins with a large, scaly, pink patch of skin on your chest or back. Next you’ll notice one patch of pink skin quickly followed by more. Your skin will be itchy and red or inflamed. The number and sizes of spots can vary.

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Causes

We don’t know what causes pityriasis rosea. But there is evidence that suggests pityriasis rosea may be caused by a virus because the rash resembles certain viral illnesses. The rash doesn’t seem to spread from person to person.

Symptoms

The primary symptom of pityriasis rosea is that large, scaly, pink area of skin followed by more itchy, inflamed, or reddened patches. Pityriasis rosea affects the back, neck, chest, abdomen, upper arms, and legs. The rash can differ from person to person.

Diagnosis

A doctor can usually diagnose pityriasis rosea by looking at it. They may do blood tests, scrape your skin, or do a skin biopsy to rule out other skin conditions.

Treatment

If your case is mild, you may not need treatment. Even more serious cases sometimes go away on their own. Oral antihistamines (like diphenhydramine), over-the-counter medications you rub on your skin, and prescription steroids can help soothe the itch.

Sores may heal faster with some exposure to sunlight or ultraviolet light. Don’t get too much sun, though. In most cases, pityriasis rosea goes away within 6-12 weeks.

WebMD Medical Reference Reviewed by Hansa D. Bhargava, MD on July 31, 2020

Sources

SOURCES: 

American Academy of Dermatology. 

Australasian College of Dermatology.

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