Jock itch (tinea cruris)

What it is

Jock itch is a fungal infection of the groin and inner thighs that causes an itchy rash with a raised edge. It is common in men, athletes and in hot weather.

How it works

Tinea cruris is a dermatophyte fungal infection of the groin. It spreads outwards from the folds with a raised edge.

Why it matters on darker skin

Heat, sweat and tight clothing create the warm, damp environment fungi love. On darker skin it may look brown or grey rather than red.

Causes and triggers

Heat, sweat, tight clothing, athlete's foot spreading via towels, diabetes.

What helps — and why it works

Wash and dry the groin thoroughly every day, change underwear daily, wear loose cotton and use a plain antifungal cream for the full course. Treat athlete's foot at the same time, because it often spreads from feet to groin: put socks on before underwear. Antifungal cream twice daily: kills fungus. Expected timeline: itch better in days; continue 2 weeks after clear. Dry thoroughly, loose underwear: removes moisture. Expected timeline: ongoing. Treat feet too: common source. Expected timeline: 2–4 weeks.

What to avoid and why

Avoid "mixed" creams containing steroids, sharing towels and staying in sweaty clothes after exercise.

Common mistakes

• Steroid creams.
• Stopping early.

Body care basics in a hot climate

Heat and humidity mean the body sweats more, which feeds the bacteria and yeasts that cause odour, rashes and some types of body acne. A daily lukewarm shower with a gentle, soap-free or mild cleanser, thorough drying of skin folds and between toes, and fresh, breathable cotton clothing prevent many problems. Moisturise straight after bathing while skin is still damp so water is sealed in; this matters even in humid months because frequent washing strips natural oils, and it matters most during harmattan. Avoid sharing towels, razors and sponges, which spread fungal and bacterial infections. When shaving, use a sharp blade, shave with the grain and do not stretch the skin; for curly hair a guarded trimmer is often better. Be cautious with body-lightening, 'carrot' or 'toning' lotions: many contain undeclared steroids or mercury. If a rash spreads, keeps coming back, or appears with fever, see a doctor rather than trying more creams.

Choosing body products

For most people an unscented, gentle cleanser and a plain moisturiser are enough. Antiperspirants containing aluminium salts are the most effective way to reduce sweating and are best applied at night to dry skin. Fragranced body sprays and deodorants are a common cause of allergy; fragrance-free options are kinder to sensitive skin. Aerosol products are easy to over-apply and some have been recalled for benzene contamination, so roll-ons and creams are a sensible default. For fungal rashes, plain antifungal creams such as clotrimazole are better than combination creams containing strong steroids, which can make infections spread. Always check for a NAFDAC number and a full ingredient list.

Questions to ask your doctor or pharmacist

Useful questions include: What do you think is causing this? Is it likely to come back, and how can I prevent it? Which products should I stop? How long before I should expect improvement, and when should I come back if it isn't better? Are there side effects to watch for? Is this treatment safe if I am pregnant, breastfeeding or for my child? Writing your questions down, bringing your products (or photos of their labels) and taking dated photos of the problem make an appointment much more useful.