These itchy rashes are caused by the same kind of fungus. How to recognize them, how long to use an antifungal cream (longer than most people think) and when you need a doctor.
One kind of fungus, several names
Athlete's foot, jock itch and ringworm are all skin infections caused by fungi called dermatophytes (the medical name is tinea). Despite its name, ringworm has nothing to do with worms. The fungi grow in warm, damp places and spread through direct contact – with people, pets, or surfaces such as locker room floors and shared towels.
| Name | Where | What it looks like |
|---|---|---|
| Athlete's foot (tinea pedis) | Between the toes and on the soles | Itchy, scaly, peeling or cracked skin, often between the fourth and fifth toes; sometimes burning or blisters |
| Jock itch (tinea cruris) | Groin, inner thighs and buttocks | A red, itchy rash with a raised edge; it usually doesn't affect the scrotum |
| Ringworm (tinea corporis) | Body, arms, legs and face | A round, red, scaly patch with a raised, ring-shaped edge and clearer skin in the middle |
| Nail fungus (onychomycosis) | Usually the toenails | Thick, yellow or white, crumbly nails |
How to treat it
Most skin infections clear up with an over-the-counter antifungal cream, such as clotrimazole 1%, miconazole or terbinafine.
- Wash and dry the area thoroughly, then apply a thin layer twice a day, covering a little of the healthy skin around the rash.
- With clotrimazole, keep going for 4 weeks for athlete's foot and ringworm, and 2 weeks for jock itch – even if the rash fades sooner. Stopping early is the main reason it comes back.
- Don't use a steroid cream such as hydrocortisone on its own on a fungal rash. It can calm the itch for a while but let the fungus spread.
Nail fungus and ringworm of the scalp need prescription tablets, because creams can't reach deep enough. Options include terbinafine and itraconazole. These medicines can interact with other drugs and aren't suitable for everyone – for example, itraconazole isn't used in people with heart failure – so your doctor will decide. PharmacyFarm dispenses them after our pharmacist has verified your prescription.
How to stop it coming back
- Dry your feet thoroughly after washing, especially between the toes.
- Wear socks that wick moisture away, and change them every day.
- Let shoes dry out between wears, and wear sandals in locker rooms and around pools.
- Don't share towels, shoes or clothing.
- Change out of sweaty clothes soon after exercise.
- If you have athlete's foot, put your socks on before your underwear, so you don't spread it to the groin.
- Check pets for patches of hair loss, which can be ringworm, and take them to a vet.
When to see a doctor
See a doctor if:
- The rash hasn't improved after 2 weeks of treatment, or it spreads
- You have diabetes or poor circulation – foot infections can become serious
- You have a weakened immune system
- The area becomes swollen, warm, painful or oozes pus, or you see red streaks or have a fever – signs of a bacterial infection
- It affects your scalp or nails
Our guide to antivirals and antifungals covers other fungal infections, including nail fungus and yeast infections.