Erythrasma: Symptoms, Types, Causes, Diagnosis, Treatment and Prevention — What You Need to Know
Updated: 2 hours ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer: Erythrasma is a common, mild bacterial skin infection caused by Corynebacterium minutissimum — a bacterium that normally lives on the skin but grows out of control in warm, moist areas. It appears as discolored, slightly scaly patches with clear edges, usually reddish-brown, pink-brown or darker than your usual skin tone, most often in the groin, armpits, between the toes, under the breasts and other skin folds. Many people notice no symptoms at all, though the patches can be mildly itchy or uncomfortable. It is not a sexually transmitted infection. Antibiotics — topical or oral — usually clear it, and simple skin care helps keep it from returning.
What the research says
Erythrasma is often mistaken for athlete's foot. Among 122 patients with toe-web lesions thought to be tinea pedis, 46.7% had erythrasma, and fungal tests were also positive in 40.35%. (Inci et al., J Eur Acad Dermatol Venereol, 2012)
Wood's lamp alone misses many cases. Of 182 patients with interdigital lesions, 73 (40.1%) had erythrasma, but Wood's lamp alone detected only 31 (42.5%) of them. (Polat and İlhan, J Am Podiatr Med Assoc, 2015)
Fusidic acid cream and erythromycin both work well. In a double-blind trial of 86 patients, cure or improvement occurred in 87% with fusidic acid cream and 77% with erythromycin tablets, versus 42% with placebo. (Hamann and Thorn, Scand J Prim Health Care, 1991)
TL;DR: Erythrasma at a Glance
Erythrasma is a mild, sometimes recurring bacterial skin infection that forms discolored, slightly flaky patches in warm, moist areas like the groin, armpits or between the toes. A skin-dwelling bacterium (Corynebacterium minutissimum) grows out of control, often where skin rubs together. It frequently causes no symptoms, but treatment — usually antibiotics plus good skin hygiene — clears it in most cases and helps prevent recurrence.
Limitation statement: This article contains no prevalence, incidence or duration statistics; no figures are available for how common the condition is or how long untreated cases last. No statistics have been invented.
Fact | Key point |
What it is | A common, mild, sometimes recurring bacterial skin infection |
Cause | Bacteria called Corynebacterium minutissimum growing out of control |
What it looks like | Discolored, slightly scaly patches with clear edges — reddish-brown, pink-brown or darker than your usual skin tone |
Where it appears | Warm, moist areas: between toes, groin, armpits, under breasts, other skin folds |
Symptoms | Many people notice none; mild itching or slight skin discomfort when present |
Main complication | It can come back (recur), especially with continued moisture and friction |
Treatment | Topical or oral antibiotics; clean, dry skin care with loose, breathable clothing |
Outlook | Treatment usually works well; most cases don't cause lasting skin damage |
What Is Erythrasma?
Erythrasma is a common, bacterial (germ-related) skin infection that's long-lasting or can recur (return). A type of bacteria called Corynebacterium minutissimum causes it.
It usually shows up as discolored patches on your skin. These patches may look slightly scaly (dry or flaky) and have clear edges. They often appear in skin folds, like in your groin, armpits or between your toes.
You may not notice any symptoms, but the patches could be a little itchy. A healthcare provider can help you manage it.
How are bacteria involved in erythrasma?
Erythrasma happens when the bacteria Corynebacterium minutissimum grow too much on your skin. It normally lives on your skin and usually doesn't cause problems. This condition develops when the bacteria grow out of control. This often happens in warm, moist areas of your body where skin rubs together.
What are the types of erythrasma?
Providers often describe this infection in a few common patterns based on where it appears on your body.
Type | Where it appears | What it looks like |
Interdigital erythrasma | Between the toes, most often between the fourth and fifth toes | Skin may look soft, wet or scaly; may itch |
Intertriginous erythrasma | Skin folds — groin, armpits, under the breasts | Flat patches with fine scaling; skin may look thin and wrinkled, like tissue paper |
Disciform erythrasma | Chest, back or upper legs (rare form) | Well-defined scaly patches |
What Does Erythrasma Look Like?
Erythrasma shows up as flat patches on your skin with clear edges. The color may look reddish-brown, pink-brown or darker than your usual skin tone.
The surface may be scaly. It looks and feels dry or flaky. In some areas, like between your toes, your skin may look moist or soft.
It most often appears in warm, moist areas of the body, like between your toes, in your groin, in your armpits, under your breasts and in other skin folds.
What are the symptoms of erythrasma?
Many people don't notice symptoms. When symptoms do happen, they may include mild itching and slight skin discomfort.
Appearance feature | Description |
Shape | Flat patches with clear edges |
Color | Reddish-brown, pink-brown or darker than your usual skin tone |
Surface | Scaly — looks and feels dry or flaky |
Between the toes | Skin may look moist or soft instead |
Itching | Mild itching in some people |
Discomfort | Slight skin discomfort in some people |
No symptoms at all | Many people don't notice anything |
What causes erythrasma?
Erythrasma happens when the bacteria Corynebacterium minutissimum grow too much on your skin. It normally lives on your skin and usually doesn't cause problems. This condition develops when the bacteria grow out of control — often in warm, moist areas of your body where skin rubs together.
What increases the risk of erythrasma?
Common things that can increase your risk include having diabetes or obesity, or being immunocompromised; sweating a lot; living in a hot or humid climate; and wearing tight clothing that traps moisture.
Erythrasma can also happen along with fungal (yeast) infections. These are usually between your toes.
Is erythrasma a sexually transmitted infection?
Erythrasma isn't a sexually transmitted infection (STI). Moisture, friction and other factors increase your risk. Sexual activity doesn't.
How Is Erythrasma Diagnosed?
Your provider usually diagnoses this condition by looking at your skin. They may also use a Wood's lamp (a special UV light). Your affected skin may glow in a specific color under this light. This is a key sign.
Sometimes, your provider may gently scrape your skin and look at it under a microscope. This test helps rule out a fungal infection.
Diagnostic step | What happens |
Visual exam | Provider looks at your skin |
Wood's lamp exam | A special UV light — affected skin may glow in a specific color (a key sign) |
Skin scraping (if needed) | Skin is gently scraped and examined under a microscope to rule out a fungal infection |
How Is Erythrasma Treated?
Your healthcare provider may recommend different treatment options depending on the location and severity of the infection.
Topical antibiotics are creams or lotions that you put on your skin. Providers often use these first when the infection is in a small area. Oral antibiotics are pills you take by mouth. Providers may use them if the infection is more widespread or keeps coming back.
Skin care and hygiene is an important part of treatment. Keeping your skin clean (using antibacterial soap) and dry helps, and wearing loose, breathable clothing can also help prevent the infection from coming back.
Treatment option | When it's used |
Topical antibiotics | Creams or lotions applied to the skin; often used first for small-area infections |
Oral antibiotics | Pills taken by mouth; used if the infection is more widespread or keeps coming back |
Antibacterial soap | Keeps the skin clean as part of treatment |
Keeping skin dry | An important part of treatment |
Loose, breathable clothing | Helps prevent the infection from coming back |
What can I expect from treatment?
Treatment usually works well. Antibiotics can clear the infection, and most cases don't cause lasting skin damage. This is usually a mild skin condition, but it can last a long time if it isn't treated. It often shows up again in the same area, especially in warm, moist parts of your body. Your provider can help you manage it and prevent it from coming back.
Can erythrasma be prevented?
Not all cases can be fully prevented. But you can lower your risk by keeping your skin clean and dry, wearing loose, breathable clothing, reducing sweating or changing out of sweaty clothing when it becomes wet, managing conditions like diabetes, and limiting moisture and friction in skin folds.
Prevention step | How it lowers risk |
Keep skin clean and dry | Reduces the moist environment the bacteria thrive in |
Wear loose, breathable clothing | Prevents trapped moisture and friction |
Change out of sweaty clothing | Reduces sweating's effect on skin folds |
Manage conditions like diabetes | Addresses an underlying risk factor |
Limit moisture and friction in skin folds | Removes the main growth trigger |
When Should I See My Healthcare Provider?
You should see a provider if you notice discolored patches on your skin that aren't going away, if you're not sure what the skin condition is (especially since it can look like a fungal infection), or if the rash is spreading, severe or keeps coming back.
Your provider can confirm the diagnosis and help you choose the right treatment.
Clinical care-team note: "Skin changes can be easy to overlook, especially when they don't hurt or seem minor at first. But when something lingers or keeps coming back, your body may be asking for a little attention. Small steps, like keeping your skin dry and choosing breathable clothing, can make a big difference with erythrasma. And if you're ever unsure about what you're seeing on your skin, it's worth having a provider take a look so you can get clear answers and the right treatment."
Conclusion: A Mild, Treatable Skin Infection
Erythrasma is a common bacterial skin infection that forms discolored, slightly scaly patches in the body's warmest, moistest folds — the groin, armpits, between the toes and under the breasts. It's caused by Corynebacterium minutissimum, a bacterium that normally lives harmlessly on the skin but grows out of control in moist, friction-prone areas. The condition usually causes few or no symptoms, responds well to antibiotics, and rarely causes lasting skin damage. Because the patches can resemble a fungal infection, having a provider confirm the diagnosis — often with a simple Wood's lamp exam — is the fastest path to the right treatment.
Take these three steps:
1. Get an accurate diagnosis — lingering discolored patches that look fungal deserve a provider's evaluation (often with a Wood's lamp) so you receive antibiotics, not antifungals, when that's what's needed.
2. Complete the prescribed treatment — use topical or oral antibiotics as directed, keeping the skin clean with antibacterial soap and dry throughout.
3. Break the recurrence cycle — wear loose, breathable clothing, change out of sweaty clothes promptly, manage diabetes and other risk factors, and keep moisture and friction low in skin folds.
This article provides general information and is not a substitute for professional medical advice. Always consult a qualified healthcare provider for diagnosis and treatment.
Frequently Asked Questions
What is erythrasma?
Erythrasma is a common, bacterial (germ-related) skin infection that's long-lasting or can recur (return). A type of bacteria called Corynebacterium minutissimum causes it. It shows up as discolored, slightly scaly patches with clear edges in warm, moist areas like the groin, armpits or between the toes.
What causes erythrasma?
Erythrasma happens when the bacteria Corynebacterium minutissimum grow too much on your skin. It normally lives on your skin and usually doesn't cause problems. The condition develops when the bacteria grow out of control, often in warm, moist areas where skin rubs together.
Is erythrasma contagious?
Erythrasma is caused by bacteria that normally live on your own skin growing out of control. It isn't described as a condition that spreads from person to person.
Is erythrasma a sexually transmitted infection (STI)?
No. Erythrasma isn't a sexually transmitted infection. Moisture, friction and other factors increase your risk. Sexual activity doesn't.
Is erythrasma a fungal infection?
No. Erythrasma is a bacterial skin infection. However, it can look like a fungal infection, and it can also happen along with fungal (yeast) infections — usually between the toes. A skin scraping under a microscope can rule out a fungal infection.
Is erythrasma serious?
Usually not. Erythrasma is a mild skin condition that usually doesn't cause serious problems. Serious problems may happen in very rare cases. Treatment usually works well, and most cases don't cause lasting skin damage.
What does erythrasma look like?
It shows up as flat patches on your skin with clear edges. The color may look reddish-brown, pink-brown or darker than your usual skin tone. The surface may be scaly — dry or flaky. Between the toes, the skin may look moist or soft instead.
Does erythrasma itch?
It can. Many people don't notice symptoms, but when symptoms do happen they may include mild itching and slight skin discomfort.
Where does erythrasma usually appear?
It most often appears in warm, moist areas of the body: between your toes, in your groin, in your armpits, under your breasts and in other skin folds.
What are the types of erythrasma?
There are three common patterns: interdigital erythrasma (between the toes), intertriginous erythrasma (skin folds like the groin, armpits and under the breasts) and disciform erythrasma (a rare form on the chest, back or upper legs).
What is interdigital erythrasma?
This affects the skin between your toes, most often between your fourth and fifth toes. Your skin may look soft, wet or scaly, and it may itch.
What is intertriginous erythrasma?
This shows up in skin folds, like your groin, armpits or under your breasts. It appears as flat patches with fine scaling. Your skin may look thin and wrinkled, like tissue paper.
What is disciform erythrasma?
This is a rare form that can appear on areas like your chest, back or upper legs. It causes well-defined scaly patches.
What causes erythrasma between the toes?
The bacteria Corynebacterium minutissimum grow out of control in warm, moist areas where skin rubs together. Erythrasma can also happen along with fungal (yeast) infections, usually between the toes.
Who is at risk of erythrasma?
Common risk factors include having diabetes or obesity, or being immunocompromised; sweating a lot; living in a hot or humid climate; and wearing tight clothing that traps moisture.
Can diabetes cause erythrasma?
Having diabetes is listed among the common things that can increase your risk of erythrasma.
Can obesity increase the risk of erythrasma?
Yes. Having obesity is listed among the common risk factors.
Can being immunocompromised increase the risk of erythrasma?
Yes. Being immunocompromised is listed among the common risk factors.
Does sweating cause erythrasma?
Sweating a lot is a common risk factor. The bacteria grow out of control in warm, moist areas, and moisture plus friction create the conditions they thrive in.
Does weather affect erythrasma?
Yes. Living in a hot or humid climate is a common risk factor.
Can tight clothing cause erythrasma?
Wearing tight clothing that traps moisture is a common risk factor.
Can erythrasma happen with a fungal infection?
Yes. Erythrasma can also happen along with fungal (yeast) infections. These are usually between your toes.
How is erythrasma diagnosed?
Your provider usually diagnoses it by looking at your skin. They may also use a Wood's lamp (a special UV light) — your affected skin may glow in a specific color under this light, which is a key sign. Sometimes your provider may gently scrape your skin and look at it under a microscope to rule out a fungal infection.
What is a Wood's lamp test for erythrasma?
A Wood's lamp is a special UV light. Your affected skin may glow in a specific color under this light. This is a key sign in diagnosing erythrasma.
How is erythrasma treated?
Depending on the location and severity, treatment options include topical antibiotics (creams or lotions applied to the skin), oral antibiotics (pills taken by mouth), and skin care and hygiene — keeping your skin clean with antibacterial soap, keeping it dry, and wearing loose, breathable clothing.
What are topical antibiotics for erythrasma?
Topical antibiotics are creams or lotions that you put on your skin. Providers often use these first when the infection is in a small area.
When are oral antibiotics used for erythrasma?
Providers may use oral antibiotics — pills taken by mouth — if the infection is more widespread or keeps coming back.
Does erythrasma go away on its own?
Erythrasma is long-lasting and can recur. It can last a long time if it isn't treated. Treatment usually works well — antibiotics can clear the infection, and most cases don't cause lasting skin damage.
Can erythrasma come back?
Yes. It can recur, and it often shows up again in the same area, especially in warm, moist parts of your body — especially if you have continued moisture and friction in the area.
What complications does erythrasma cause?
Erythrasma usually doesn't cause serious problems (though this may happen in very rare cases). The most common issue is that it can come back (recur), especially if you have continued moisture and friction in the area.
When should I see my healthcare provider about a rash?
You should see a provider if you notice discolored patches on your skin that aren't going away, if you're not sure what the skin condition is (especially as it can look like a fungal infection), or if the rash is spreading, severe or keeps coming back.
Will erythrasma leave scars?
Most cases don't cause lasting skin damage.
Additional Resources
For further reading, these authoritative external references support the information above:
Content reviewed and produced following the Rinnit editorial framework. Last updated: September 28, 2026.
References
Inci M, Serarslan G, Ozer B, Inan MU, Evirgen O, Erkaslan Alagoz G, et al.. The prevalence of interdigital erythrasma in southern region of Turkey. J Eur Acad Dermatol Venereol. 2012;26(11):1372-6. PMID: 21977942. DOI: https://doi.org/10.1111/j.1468-3083.2011.04293.x
Polat M, İlhan MN. The prevalence of interdigital erythrasma: a prospective study from an outpatient clinic in Turkey. J Am Podiatr Med Assoc. 2015;105(2):121-4. PMID: 25815650. DOI: https://doi.org/10.7547/0003-0538-105.2.121
Hamann K, Thorn P. Systemic or local treatment of erythrasma? A comparison between erythromycin tablets and Fucidin cream in general practice. Scand J Prim Health Care. 1991;9(1):35-9. PMID: 2041927. DOI: https://doi.org/10.3109/02813439109026579
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