Ringworm is a contagious fungal infection often confused with many other rashes, which can present with red circles.
Rashes that look like ringworm but aren’t include psoriasis, pityriasis rosea, Lyme disease, nummular eczema, contact dermatitis, hives, granuloma annulare, and lupus.
Antifungal treatment helps in clearing ringworm, but other similar circular lesions will not respond to it. So, it’s essential to differentiate ringworm from other look-alikes.
Table of Contents
Before we talk about rashes that look like ringworm, let’s talk briefly about ringworm.
Ringworm
Ringworm is a fungal infection of skin, nails, or hair. Depending on which area it involves, it can have different names. The ringworm of the foot is known as athlete’s foot and the ringworm of the body – neck, trunk, and/or extremities is called tinea corporis. (Read more about how ringworm rash looks like here)
Ringworm presents with a red and itchy circular rash. These red spots usually have a clearing in the center. The edges of the circle may be slightly raised. In addition, the surface may be scaly or flaky.
In people with darker skin tones, the circular lesion can be light or dark brown in color.
Ringworm is caused by fungi called dermatophytes which feed on dead keratin of our skin. This infection is contagious and can spread to others by direct contact or contaminated surfaces.
Certain factors like a weak immune system, diabetes, excessive sweating, or a hot and humid environment can make one more prone to getting this infection.
It is treated with topical or oral antifungals. One has to complete the entire course so the lesions do not return.
Below you will find 8 rashes that can resemble ringworm.
1. Psoriasis
Psoriasis is a chronic inflammatory skin condition. The most common type is plaque psoriasis which can present with round or oval red spots and patches on the skin. The patches may be covered with silvery-white scales.
These patches are often confused with ringworm.
Psoriasis vs. ringworm
Cause: Ringworm is a contagious fungal infection, whereas the exact cause of psoriasis is not clear. Genetics, environmental factors, and the immune system may play some role.
Psoriasis is not contagious and most commonly involves elbows, knees, scalp, and trunk.
Symptoms: Psoriatic patches usually start as small bumps that come together to form raised patches; in a few cases, when the patches heal, the center may start clearing, followed by the periphery.
The psoriatic patches are covered with silvery scales; when you remove the scale, there can be pinpoint bleeding spots. This is called the Auspitz sign.
Someone with psoriasis may have changes in nails and joints. Psoriasis is a chronic skin condition and cannot be cured, whereas ringworm if adequately treated with antifungals, can be cleared entirely.
In doubtful cases, a skin biopsy or KOH preparation to rule out fungal infection may be helpful in making a diagnosis.
Treatment: Psoriasis treatment includes ingredients that can decrease inflammation and the turnover of cells. These include coal tar, salicylic acid, topical steroids, immunosuppressants, vitamin D or A derivatives, and light therapy.
2. Pityriasis rosea
Pityriasis rosea can present with a circular rash. Flu-like symptoms like fever and malaise may precede the rash. The first red circular spot is called the “Herald patch.” This can often be mistaken for ringworm due to its appearance.
Pityriasis rosea vs ringworm
Cause: The exact cause of pityriasis rosea is not clear. Some theories suggest it may be associated with certain viruses (like herpesvirus type 6) or medications. It is not contagious.
Symptoms: Pityriasis rosea rash first appears as a single large spot called the Herald patch. It is circular or oval and can be up to 10 cm. This patch usually appears on the trunk. The patch may have a raised margin and a collar of scale at the periphery. So, it can be easily mistaken for ringworm.
However, up to 2 weeks after the first spot, many small red spots (secondary lesions) appear on the body, mainly the trunk, arms, and thighs. Ringworm does not follow this pattern and usually is not this widespread.
Both ringworm and pityriasis rosea may be associated with itching, although it’s usually more prominent with ringworm.
Treatment: Pityriasis rosea rash usually clears on its own in 6-10 weeks. Antihistamines may help reduce itching.
3. Lyme disease
Lyme disease is a bacterial infection caused by Borrelia. One gets it through a bite of an infected tick. It can lead to a skin rash called erythema migrans which appears as a red circle on the skin and can look like ringworm.
Lyme disease vs. ringworm
Cause: Ringworm is a fungal infection, whereas Lyme disease is a bacterial infection. Sometimes people with Lyme disease may remember a tick bite, or they may have a recent history of travel. Lyme disease rash usually appears 3-30 days after the tick bite.
Ringworm is highly contagious, while there is no direct evidence that Lyme disease is contagious. In some rare cases, pregnant women can transfer the infection to their babies.
Symptoms: Lyme disease presents with a circular rash which has a typical bull’s eye appearance. The central red spot is surrounded by a lighter zone and a red ring at the outer edge.
Sometimes, a secondary rash appears days after the first lesion of Lyme disease.
Ringworm rash is usually associated with itching, while Lyme disease rash is usually not itchy.
Around 50% of patients with Lyme disease may develop flu-like symptoms like headache, fever, chills, joint pain, or enlarged lymph nodes.
Treatment: Lyme disease is treated with antibiotics. If Lyme disease is not treated early, it can affect vital organs like the heart, nervous system, eyes, etc. The late symptoms may include numbness, facial paralysis, abnormal heart rate, chest pain, or vision loss.
4. Nummular eczema
Nummular eczema, also known as discoid eczema, can present with round coin-shaped lesions. The surface may be scaly, and these can be easily confused with ringworm.
Nummular eczema vs ringworm
Cause: Nummular eczema is a type of eczema without a clear underlying cause. However, it is often associated with injury, dry skin, irritating skin care products, poor circulation in the legs, allergies, certain medications, or rough fabrics. On the other hand, ringworm is a contagious infection caused by fungi – dermatophytes.
Nummular eczema is not contagious and cannot spread from person to person. It often involves arms, hands, and legs.
Symptoms: It usually starts as tiny bumps which come together to form coin-shaped lesions. These may ooze clear fluid. It may be covered with a thick crust.
In comparison, ringworm has round patches with central clearing and fine scaling. In addition, nummular eczema patches are commonly seen in dry and cold weather.
Treatment: Nummular eczema is often treated by barrier repair moisturizers, steroids, antihistamines, or light therapy. It is a chronic skin condition, so one may get recurrent outbreaks.
Ringworm, if adequately treated with antifungals, can be completely cured.
5. Contact dermatitis
Contact dermatitis can present with a red circle if the skin comes in contact with any round object with an allergen (allergic contact dermatitis) or irritant (irritant contact dermatitis).
- Common allergens are metals like jewelry with nickel, poison ivy, latex, etc.
- Common irritants are fragrances, essential oils, surfactants, etc.
Contact dermatitis vs. ringworm
Symptoms: The patches of contact dermatitis are usually red, dry, and scaly. Occasionally there may be blister formation. They may be associated with itching.
In most cases, one may remember that the rash occurred following contact with something. The rash will be localized to areas of contact and doesn’t spread as it is not contagious like ringworm.
Treatment: Contact dermatitis is treated by avoiding irritants, allergens, and medications like antihistamines and steroids.
6. Hives
Hives, aka urticaria, can present with a circular rash that may be red, skin-colored, or slightly darker than skin. These can occur due to certain foods, medications, or other environmental factors.
Ringworm vs hives
Symptoms: Contrary to ringworm, which is scaly, urticaria presents with red bumps with a smooth surface. They are usually round or oval but can be of any shape. They can be a few mm to several cm in size.
If you press hives, they turn pale, unlike other rashes. This is called blanching.
Treatment: In most cases, hives usually clear in around 24 hours on their own. In some cases, antihistamines or prescription medications may be needed.
Note: Hives can sometimes be associated with angioedema, which is similar to hives but the swelling is deeper in the skin. It can be serious if it affects the airways. Occasionally, hives can be associated with a serious allergic reaction called anaphylaxis. This condition can lead to chest tightness, difficulty in breathing, dizziness, and confusion. Anaphylaxis is a medical emergency, and one should go to the hospital immediately if experiencing such symptoms.
7. Granuloma annulare (Localized)
Granuloma annulare is of different types. Localized type is the most common which presents with red ring-shaped lesions on feet, hands, or fingers.
Granuloma annulare vs. ringworm
Cause: Ringworm is a contagious fungal infection, whereas granuloma annulare is an inflammatory skin condition with unclear underlying causes. It is often associated with an injury, insect bite, infection, medications, or sun exposure.
It usually occurs in children and young adults and often involves hands, feet, and fingers.
Symptoms: The lesions of granuloma annulare are round rings with smooth surfaces. The center may be depressed. Ringworm patches are usually rough and scaly. Both these can have clear central areas.
Granuloma annulare usually doesn’t itch, while ringworm causes intense itching.
Treatment: Granuloma annulare spots may resolve on their own. Treatment may clear the lesions faster.
The treatment may include:
- Topical steroids or calcineurin inhibitors
- Oral medications like steroids or antimalarials
- Freezing
- Laser
8. Lupus
Cutaneous lupus is a group of disorders that affect the skin. The three main types are: acute, subacute, and chronic.
Acute lupus presents with a red rash on the cheeks and nose in a butterfly pattern. Both subacute and chronic lupus can present with red circular patches, which may resemble ringworm.
Lupus vs ringworm
Cause: The exact reason behind lupus is not clear. Genetics, environmental factors, and the immune system may play a role. Unlike ringworm which is a contagious fungal infection, lupus is not contagious.
Subacute cutaneous lupus presents with red, raised, circular scaly spots commonly on sun-exposed areas like the upper arms or trunk. These spots can have central clearing like ringworm. However, these spots are usually associated with sun exposure and are seen commonly in adult females.
Discoid lupus is the most common type of chronic cutaneous lupus. It presents with round and red scaly patches or plaques, which can lead to scarring and hair loss. It commonly involves the scalp, ears, cheeks, nose, and lips. These lesions usually do not have clearing in the center.
Most lesions of subacute and chronic skin lupus are not itchy whereas ringworm is often associated with itching.
Treatment: Lupus is a chronic condition often treated with topical steroids, oral steroids, antimalarials, or immunomodulators.
Key points
Ringworm is a common cause of circular rash; however, many other skin conditions can present similarly.
Other rashes that can present with red circles on the skin but are not ringworm include psoriasis, pityriasis rosea, Lyme disease, nummular eczema, contact dermatitis, hives, granuloma annulare, and lupus.
If you are not sure what is causing the rash, it’s best to see a doctor to get the proper diagnosis. Timely diagnosis and treatment can prevent the worsening of the skin condition.
If you are treating your circular rash with antifungals and it is not improving, it’s best to get medical attention.
References
- Robinson CA, Love LW, Farci F. Nummular Dermatitis. [Updated 2022 Oct 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan.
- Schmieder SJ, Harper CD, Schmieder GJ. Granuloma Annulare. [Updated 2022 Apr 18]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan.
- Litchman G, Nair PA, Le JK. Pityriasis Rosea. [Updated 2022 Jul 18]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan.
- Lyme disease – Transmission. CDC.
Disclaimer: This blog post is for information purposes only and does not replace medical advice.