A circular rash can stem from a number of skin conditions. Often, ringworm (a fungal skin condition) is suspected, but rashes may look like ringworm and be something different. Some of the causes of a circular rash are an allergic reaction, infections, or other skin conditions. This article will explain the causes of a circular rash.

Ringworm

Ringworm (tinea corporis) is a skin infection that is caused by a fungus. It is common in children, but can affect people of all ages. The ringworm fungus likes moist and warm areas. It can grow on the surface of the skin, on the scalp, on nails, on the feet, between the toes, and on the bottom of the feet.

Ringworm is contagious. It can spread from person to person and from pet to person. Ringworm can be caught from contaminated items such as those found at the pool, shower, or sink, including clothing, makeup, brushes, and combs.

Signs

Ringworm presents as a ring-shaped patch. There are differences in its appearance depending on where the ringworm grows on the body. Some of the common signs of ringworm are:

• The center of the patches of ringworm typically is clear at first.
• The patch is excessively itchy.
• The patch is raised, round, and flat, and has a raised border that is scaly.
• Depending on the person's skin tone, the patches can be pink, red, gray, or brown.

Other Causes

Lyme Disease

Lyme disease is a bacterial infection spread by the bite of an infected tick. It is most often contracted by people living in or visiting the Northeast and northern Midwest.

Symptoms of Lyme disease vary depending on timing. If left untreated, the infection can lead to other health conditions. In addition, the infection is known to spread to the heart, nervous system, and joints. Typically, the symptoms appear between three and 30 days after the bite and include the following:

• Headache
• Chills
• Fever
• Aches in joints
• Swollen lymph nodes

These symptoms may occur before the rash or instead of the rash. Contact your healthcare provider if you have any of these symptoms after getting bitten by a tick.

The rash from the infected tick bite, erythema migrans, affects about 70% to 80% of people with Lyme disease. Signs of Lyme disease rash include:

• The rash appears on any area of the body.
• The rash typically appears at the site of tick bite within seven days, but it may appear within three to 30 days.
• The rash can grow up to 12 inches.
• The area is warm when touched.
• It has a “bull’s–eye” appearance.
  

Other Lyme disease symptoms that can occur later include:

• Irregular heartbeat
• Nerve pain
• Numbness or tingling in hands and feet
• Heart palpitations
• Severe headache and neck stiffness
• Arthritis and joint swelling in large joints
• Tendon pain
• Dizziness
• Shortness of breath
• Temporary paralysis of facial muscles in which one side of the face droops (Bell’s palsy)

Eczema

Eczema (atopic dermatitis) is an inflammatory skin condition that is typically very itchy and appears as dry rashes, scaly patches, or blisters. Over 31 million Americans are affected by this condition. It can develop in people of all ages, including newborn babies.

Some people have a mild form of eczema, while others have a more severe form needing specialized treatment. The rash can appear anywhere on the body and in multiple locations.

Nummular eczema is a type that causes red or brown coin-shaped or oval patches. They are dry and scaly. It can be very itchy and is often seen on the arms and legs.

Some people with eczema also have allergies and other skin conditions. Some common symptoms of eczema include:

• Itching
• Dry patches of skin
• Round thick and hard patches
• Discoloration of skin
• Bleeding or leaking of clear fluid when the area is scratched

Granuloma Annulare

Granuloma annulare is a skin condition that affects people of all ages. The cause is unknown, it is not contagious, and it clears up on its own. The skin condition is a circular ring of raised bumps that has a sunken center.

It is known to be common in people who have diabetes or thyroid disease. As it looks similar to other skin conditions, it is important to visit your healthcare provider for a proper diagnosis.

The most common signs of granuloma annulare are:

• A number of rings of bumps on the hands, feet, or legs
• Red or skin-toned bumps that are thick and firm
• A ring that stays in one area or spread to multiple of areas
• Rings that remain for several years

Contact your healthcare provider if you have a ring anywhere on your skin that lasts more than a few weeks.

Psoriasis

Psoriasis is a skin condition that accelerates the time that new skin cells are made—a matter of days rather than the usual weeks. Skin cells begin to pile up, causing itchy, red, sometimes circular patches of skin that join together.

The patches are typically scaly, thick, and discolored. Some of the patches may be painful and excessively dry with stinging and burning. Psoriasis will commonly show up on the hands, feet, knees elbows, scalp, and back. Some of the common symptoms of psoriasis include the following:

• Dry, cracked skin
• Excessively dry skin that may itch and/or bleed
• Soreness, burning, and painful itching
• Discolored (e.g., pink, red, purple, or brown, depending on underlying skin tone) round patches or plaque-like patches of skin with silvery and thick scales

Pityriasis Rosea

Pityriasis rosea is a common skin condition that usually runs its course and goes away without treatment. Its cause is still unproven, but it is thought to be viral. This condition most often appears in younger people, ages 10–35.

This condition starts with what is called a herald patch. It is round or oval, red or pink in color, and has a raised edge. It usually appears on the trunk and can be from 0.8 inches to almost 4 inches wide.

But typically within days to weeks, more oval patches appear and follow the Langer lines (folds) of the front and back of the trunk, arms, and legs. These are usually smaller, 0.4–0.8 inches wide.

Before the herald patch appears, the person may feel like they have a cold or the flu, with symptoms of a sore throat, fatigue, nausea, and headache. The rash often isn't itchy, but it is itchy in about half of people with the condition.

In cases where the rash or itching is severe corticosteroids may be prescribed.

Treatments

The treatments for circular rash will vary. Antibiotics are needed for Lyme disease. For other rashes, your healthcare provider will often recommend home remedies and over-the-counter (OTC) products before suggesting prescription medications and treatments.

Home Remedies and OTC Products

Ringworm:

• You may begin by using OTC antifungal creams twice a day for seven to 10 days.
• Don't cover the ringworm rash with a bandage.
• Keep the area clean and dry.

Eczema, psoriasis, and pityriasis rosacea:

• Keep the skin hydrated with OTC fragrance-free, hypoallergenic, emollient-rich lotion after bathing.
• Bathe in lukewarm water and use a mild cleanser rather than soap.
• Wear loose, non-scratchy clothing.
• A wet wrap treatment in which you apply petroleum jelly and wrap the area in plastic wrap or a wet bandage may provide relief.
• An oatmeal bath may also help, adding finely ground oatmeal powder or a commercial oatmeal bath product to your bath.
• Products that contain coal tar can be useful.
• You may also use OTC hydrocortisone cream for these conditions, as well as granuloma annulare.
• If itching is bothersome, applying a cool compress may help.

Prescriptions and Treatments

The type of treatment that you have depends on the specific condition:

• Antifungal medication can help people who have ringworm. It can come in creams, ointments, and pills. Most creams and ointments are available without a prescription. In some cases, the healthcare provider may need to prescribe antifungal pills for severe disease.
• Antibiotics usually are prescribed for people who have Lyme disease. If antibiotics are given early enough, there is a higher chance of full recovery and prevention of complications.
• Liquid nitrogen (applied to the skin) is a treatment option for granuloma annulare if it is extreme and widespread. Other options for widespread granuloma annulare are Aczone (dapsone), retinoids, and niacinamide. Typically, this condition clears up on its own.
• Corticosteroids are commonly prescribed for skin conditions, including eczema, psoriasis, pityriasis rosea, and granuloma annulare. They are available in lotions, shampoos, creams, and ointments.
• Light therapy (phototherapy) is a treatment that can help patients with eczema and psoriasis. It exposes skin to a controlled amount of light. This treatment can be used with other treatments or on its own. Your healthcare provider can help come up with the best plan based on the specific condition.

When to Talk to Your Healthcare Provider

There are several reasons why you may develop a circular rash. If you do have a rash and it is excessively itching, painful, and not going away within a few days, contact your healthcare provider.

In addition, if you were bitten by any type of insect (including a tick) and notice a rash appearing on your body, please contact your healthcare provider immediately. They can help you determine the type of rash and the right treatment option for you.

Summary

A circular rash is typical of ringworm (a contagious fungal skin infection. But it may also occur due to other skin conditions such as Lyme disease, eczema, psoriasis, pityriasis rosea, or granuloma annulare. Contact your healthcare provider for a diagnosis of any circular rash that does not resolve quickly. The type of treatment given will depend on the cause of the rash.

A Word From Verywell

A circular rash can happen at any time throughout a person's life, from newborns to older adults. If you develop a circular rash, know that you are not alone.

If you have a rash of any shape and it is not going away, give your healthcare provider a call. They can help you determine the proper diagnosis and treatment options. If you encounter a rash and you are not sure what to put on it, call your healthcare provider, who can recommend options prior to your appointment.