Ringworm: What you should know

Pie con descamación y fisuras entre los dedos por tiña del pie

By Dr. Rodolfo SuárezSeptember 18, 20266 min read

Ringworm is a common and treatable fungal infection, but it is often mistaken for eczema or other types of dermatitis, which delays its control and allows it to spread. In this article, we explain, clearly and without alarmism, how to recognize its most common forms, why it appears, what safe measures you can start taking at home today, what mistakes to avoid (especially the use of corticosteroids without medical advice and supervision), and in what situations it is important to consult a doctor to confirm the diagnosis and choose the appropriate treatment.

Before you read: At Skinpaths, we distinguish between opinion and evidence. To write this content, we prioritized indexed medical sources and recommendations from scientific societies. You’ll find the complete bibliography at the end for your reference.
Important: This article is for informational purposes only and does not replace medical advice. If you have any questions, persistent symptoms, or your condition worsens, consult a healthcare professional.

Summary in 60 seconds

Ringworm is a fungal infection (dermatophyte infection) that can affect the skin, feet, groin, scalp, and sometimes nails. It usually causes scaly, itchy patches; it often spreads outward, with the border being more noticeable than the center. It is contagious through direct contact and shared objects (towels, combs, sportswear). Many forms of ringworm on the skin respond to topical antifungals, but ringworm of the scalp and some extensive cases usually require oral treatment. Avoiding corticosteroid creams «just in case» is key: they can mask and worsen the infection. If it doesn’t improve, spreads, or affects specific areas, it’s advisable to consult a doctor.

Ringworm is not ‘just a spot’: if not treated properly, it can spread and become contagious, even within the same house.”

What is it?

Ringworm (also called tinea capitis) has nothing to do with worms: it’s an infection caused by fungi that live in the superficial layers of the skin, hair, or nails. It can be called by different names depending on the affected area.

Ringworm (body)
Tinea pedis or athlete’s foot
Jock itch
Ringworm of the scalp (tinea capitis)

Why does it appear? (common causes)

Ringworm occurs when the fungus finds favorable conditions (warmth, moisture, friction) and manages to colonize the skin. It is usually transmitted through:

Skin-to-skin contact with an infected person.
Shared items : towels, clothes, helmets, combs, razors.
Wet surfaces (changing rooms, showers) and sports equipment.
Animals (especially cats and dogs) with fungal lesions.

There are factors that make it easier for it to persist or reappear: sweating, poorly ventilated footwear, contact sports, close living arrangements, and, in some people, diabetes or low immunity.

What does it look like and what symptoms does it cause?

The presentation varies by area and skin tone, but typically includes:

Round or oval plaque , with a more active border (redder/darker, raised or scaly) and a relatively lighter center .
Variable itching/itching .
Scaling (sometimes fine, sometimes marked).

According to location:

Feet: maceration and peeling between toes, bad odor, cracks.
English: itchy plaques in folds, often sparing the scrotum.
Scalp: flaking, itching, areas of brittle hair or hair loss; in more inflammatory cases, there may be pain, bumps (kerion), and tender lymph nodes. Oral treatment is usually required in this area. CDC 2026 ; British Association of Dermatologists 2023

Important: It can be confused with eczema , psoriasis, contact dermatitis, or pityriasis rosea. If the lesion is not textbook, the clinical diagnosis may be incorrect.

What can you do today? (safe and concrete measures)

If you suspect ringworm on the skin (not scalp) and it is limited:

Keep the area clean and dry , especially after showering or exercising.
Do not share towels, sportswear, combs, hats, or helmets until this is resolved.
Change and wash underwear/socks daily if the area requires it.
Consider using an over-the-counter topical antifungal, following the package insert (application and duration). Treatment usually takes weeks , although you may see improvement sooner. CDC 2026
If pets have skin lesions or localized hair loss, consult a veterinarian : treating only the person may not be enough if the reservoir remains in the home.

What NOT to do? (common mistakes)

Do not use corticosteroid creams (alone or in combination) to «reduce inflammation» of a lesion that could be ringworm: they can worsen it, change its appearance, and delay diagnosis . CDC 2026
Do not stop the antifungal treatment as soon as it «looks better»: it is a frequent cause of relapse.
Do not occlude the injury (closed bandages) if moisture increases.
Do not rely on irritating remedies (acids, alcohols, uncontrolled essential oils): they can damage the skin barrier and complicate the picture.

When should I consult?

Consult your dermatologist if any of these scenarios occur:

Scalp (scaling with hair loss, painful or suppurative plaques).
Nails (thickening/persistent yellowing) or suspicion of extensive tinea.
Face, beard, genitals , or very inflamed lesions.
Fever , significant pain, pus, extensive scabs, or general malaise.
Diabetes, immunosuppression , pregnancy, or relevant comorbidities.
It does not improve after 1–2 weeks of appropriate management or it continues to spread .
Recurrent outbreaks at home (possible reservoir: contacts, pets, fomites).

What does a dermatologist usually do?

In consultation, the usual approach is:

History and exploration (pattern, associated areas, coexistence, pets).
If there is any doubt, a sample can be taken from the active edge for:
- Microscopic examination (e.g., KOH).
- Culture is needed to confirm the fungus and guide treatment, especially if the infection is persistent or widespread. Leung 2020
- Skin biopsy if other conditions are suspected that may be confused with the present clinical picture.
You will choose treatment according to the area:
- Topical use in many skin ringworms.
- Oral when appropriate (e.g., scalp; extensive or resistant cases), assessing interactions and safety.

Frequently Asked Questions

Does ringworm always form a perfect «ring»?

No. The “ring” is a classic pattern, but it can be irregular, multiple, or subtle, especially if corticosteroids were used or if it is in skin folds.

Can ringworm be spread through clothing or towels?

It can be transmitted through contaminated objects (towels, clothing, combs, helmets), in addition to direct contact. Therefore, it is recommended not to share them and to wash them properly. CDC 2026

How long does it take to leave?

It depends on the area, extent, and adherence. Many skin infections improve with topical treatment within weeks, but scalp and nail infections usually require longer periods and medical supervision.

Can I go to the gym or the pool?

In general, yes, but with strict precautions: cover the area if possible without occluding it, practice careful hygiene, wear sandals in showers/changing rooms, and do not share towels or equipment. If there are extensive or very active lesions, consult a doctor for recommendations specific to your case.

How to differentiate between ringworm and eczema?

Ringworm usually has a more pronounced, scaly border and tends to spread; eczema can be more diffuse and very itchy, with a history of sensitive skin. Even so, they are frequently confused: if in doubt, clinical confirmation is best.

Why might a corticosteroid cream make it worse?

Because it reduces inflammation «on the surface» but does not eliminate the fungus , it can allow it to spread and change its appearance (tinea incognito), making diagnosis more difficult. CDC 2026

Are there any types of ringworm that are «resistant» to treatment?

Cases of resistance to some antifungals have been reported in various regions. If the condition does not improve with appropriate use or worsens, the diagnosis and treatment should be reassessed. CDC 2024