Ringworm (dermatophyte infection)
Ringworm is a fungal infection of the skin caused by dermatophytes. Despite the name there is no worm involved: the name comes from the ring shape of the…
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Medicines commonly prescribed for Ringworm (dermatophyte infection)
For informational purposes only. Always consult a doctor before using any medicine.
Dosage form: CAPSULE, 150 mgActive substance: fluconazoleManufacturer: Pharmathen S.A.Prescription requiredDosage form: CAPSULE, 200 mgActive substance: fluconazoleManufacturer: Vinci Farma, S.A.Prescription requiredDosage form: CAPSULE, 50 mg fluconazoleActive substance: fluconazoleManufacturer: Laboratorios Normon S.A.Prescription required
Ringworm (dermatophyte infection)
Ringworm is a fungal infection of the skin caused by dermatophytes. Despite the name there is no worm involved: the name comes from the ring shape of the lesion. It is contagious, treats well, and the commonest error is treating it with steroids in the belief that it is eczema, which spreads it and disguises it.
How it looks
- a round or oval patch with an active, scaly border that is redder and more raised than the centre;
- the centre clears as the lesion expands outwards;
- sometimes small blisters or pustules at the border;
- itching, to a variable degree;
- it grows slowly and there may be several lesions that merge;
- on darker skin the redness is less apparent and scaling and pigment change predominate.
By location
- body: the classic ring on the trunk and limbs;
- groin: plaques in the groin creases spreading to the thighs, with a clear border; it usually spares the scrotum, which helps distinguish it from candidiasis;
- feet: athlete's foot, between the toes or on the sole;
- hands: dry scaling on one palm, often alongside both feet being affected;
- scalp: mainly in children; areas of hair broken off short, scaling and sometimes a boggy, painful swelling. It never clears with creams: it needs oral antifungal treatment;
- nails: thickening and colour change, with their own prolonged treatment;
- beard: pustules around the hairs, in men.
How it spreads
- from person to person, by direct contact or via towels, clothing, combs and sports equipment;
- from animals: cats, dogs, rabbits, guinea pigs and livestock. This is a very common route in children, and the pet should be checked;
- from soil and shared damp surfaces: changing rooms, pools, mats;
- from one part of your own body to another: the feet infect the groin and hands;
- moisture, heat, sweating, tight clothing, diabetes and reduced immunity all make infection more likely.
The steroid mistake
This deserves its own section. If a steroid cream is applied to ringworm, the itch and redness improve for a few days while the infection spreads underneath. The result is what is called tinea incognito: an extensive lesion with blurred borders, hard to recognise and hard to treat. Many over-the-counter creams combine an antifungal with a potent steroid, and those are precisely the ones that produce this problem. For a ring-shaped lesion with a scaly border, the correct choice is an antifungal alone.
When to see a doctor
- the lesion is on the scalp or in the beard area;
- there are many lesions or they are extensive;
- there is no improvement after two weeks of topical antifungal;
- you have used a steroid cream and it has worsened or changed appearance;
- there is pus, pain, swelling or fever;
- the nails are affected;
- you have diabetes or reduced immunity;
- it is a child with areas of broken hair;
- it keeps coming back.
Diagnosis
By appearance and with skin scrapings for microscopy and culture. It is worth doing when the picture is unclear or when prolonged oral treatment will be needed, because granuloma annulare, discoid eczema, psoriasis and pityriasis rosea look similar and do not respond to antifungals.
Treatment
- topical antifungal — terbinafine, clotrimazole, ketoconazole — for 2–4 weeks, applied to the lesion and about 2 cm beyond the border;
- continue for a week after the skin has cleared: stopping when the symptoms go leads to relapse;
- oral antifungal for scalp and beard ringworm, extensive disease, nail involvement and where topical treatment fails;
- antifungal shampoo as an adjunct in scalp ringworm, to reduce transmission;
- treat the feet at the same time if they are affected: they are the usual source of groin reinfection;
- take the pet to the vet if the infection came from an animal;
- antibiotics only if there is added bacterial infection.
How to avoid spreading it
- do not share towels, clothing, combs, hats or sports equipment;
- wash bedding and towels at a high temperature;
- flip-flops in showers and changing rooms;
- shower after training and dry the skin folds thoroughly;
- breathable clothing changed daily;
- children with scalp ringworm can attend school once treatment has started;
- check household members if cases recur.
Common questions
Is there a worm? No. The name comes from the ring shape of the lesion.
Can I use the pool? Better to wait until the lesion has been treated; if you go, cover it and dry thoroughly.
Will the hair grow back? Yes, after treating scalp ringworm, unless there was a severely inflammatory form that scarred. That is why treating it early matters.
Do home remedies work? They do not eliminate the fungus and they delay effective treatment.
Can I use the cream left over from last time? If it is a plain antifungal and in date, yes. If it contains a steroid, no.
Online consultation
In an online consultation the doctor reviews photographs, distinguishes ringworm from eczema, psoriasis and granuloma annulare, checks whether you have used steroid creams that have altered the picture, decides whether oral treatment is needed and advises how to prevent spread at home.
This material is for information only and does not replace a medical consultation.
Medically reviewed by
Reviewed on Jul 30, 2026
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