Fungal skin infections

Also called Ringworm, Athlete's foot, Fungal nail infection, Thrush, Tinea

Common, treatable, and routinely mistaken for eczema. Steroid cream on a fungal rash makes it spread.

What it is

Infections of the skin, nails or moist body folds by fungi and yeasts. Ringworm is not a worm; it is a fungus, named for the ring-shaped rash.

They turn up in predictable places: between the toes, in the groin, under the breasts and in other skin folds, on the scalp in children, and under the nails.

The mistake that matters is treating one as eczema or psoriasis. A steroid cream suppresses the redness and the itch while the fungus spreads, producing a rash that looks odd, behaves oddly and gets worse each time the cream is used. If a rash improves on steroid and returns worse, think fungal.

Some cases matter more than a cosmetic nuisance. In diabetes and peripheral arterial disease, athlete's foot cracks the skin and is a common entry point for cellulitis. Fungal nails in an older person cause thick nails that cannot be cut, which leads to pressure damage. Oral thrush in an adult who is not obviously unwell can point to an inhaler technique problem, diabetes or a weakened immune system.

Scalp ringworm in children needs oral treatment; creams do not reach the hair root, and it can cause permanent hair loss if left.

Signs you might notice

Ringworm: a red or darker ring with a clearer centre and a raised, scaly edge, slowly spreading, usually itchy.

Athlete's foot: itchy, cracked, peeling skin between the toes, sometimes with a smell.

Fungal nail: thickened, crumbly, yellow-brown nails, often after long-standing athlete's foot.

Skin folds: red, sore, sometimes glazed or weeping skin under the breasts, in the groin or in abdominal folds, often with small spots at the edge.

Oral thrush: white patches in the mouth that leave a raw area when rubbed off, soreness, and a bad taste. See oral thrush.

See a GP for: scalp involvement in a child; any fungal infection in somebody with diabetes; spreading redness, heat or pain, which may be cellulitis; nails that need treating; or a rash that has not responded to a week or two of the right cream.

How it can affect day-to-day life

In care settings, skin folds are where this lives and where it is most often missed, because it needs somebody to look under rather than at. Moisture, warmth and friction do the rest.

Treatment failure is nearly always about duration. Antifungal creams are stopped when the rash looks better rather than after the recommended course, usually one to two weeks past clearing, and it returns.

Fungal nails take months of treatment and often do not fully clear, which is worth saying at the start rather than discovering.

Reinfection from shoes, socks, towels and shared bathrooms is common, and treating the person without treating the environment produces a loop.

Older people who cannot reach or see their feet may have long-standing athlete's foot nobody has looked at. See podiatry.

Supporting someone well

Look, including under and between: between all the toes, under the breasts, in the groin, in abdominal folds.

Treat with the right antifungal for at least the full course, and keep going for a week or two after it looks clear.

Do not put a steroid cream on an undiagnosed rash. If a rash gets worse on steroid, stop and reconsider.

Keep the area dry: dry thoroughly after washing, especially between the toes and in folds, and use a barrier product where advised rather than talc.

Change socks daily, alternate shoes, use flip-flops in communal showers, and do not share towels.

For diabetes, treat athlete's foot promptly and get any break in the skin looked at. This is a cellulitis prevention step, not a cosmetic one.

For a child with scalp ringworm, see a GP; this needs tablets and the school and household should be checked.

For repeated oral thrush in an adult, ask why: inhaler technique, dentures, diabetes, or immune suppression.

Where to get help

A pharmacist first for most skin and foot infections, including through Pharmacy First.

A GP practice for scalp ringworm in children, nail treatment, any infection in a person with diabetes, or a rash that is not responding.

Same-day help for spreading redness, heat, swelling or fever, which may be cellulitis.

British Association of Dermatologists publish patient information leaflets on each of these.