Ringworm and athlete's foot: fungal skin infections, a review

Fungal skin infections spread through close contact and shared items, but ringworm is usually treatable with medicine from a pharmacy. This article explains ringworm and athlete's foot using information from the NHS and the US Centers for Disease Control and Prevention (CDC).

1. Introduction

Ringworm is a common fungal infection of the skin, scalp or nails. Despite the name, it is not caused by a worm ^{[1, 2]}. The CDC explains that athlete's foot (tinea pedis), jock itch (tinea cruris), scalp ringworm (tinea capitis) and most fungal nail infections are all forms of ringworm ^[2].

2. Signs and symptoms

The main symptom of skin ringworm is a rash that may be scaly, dry, swollen or itchy. It is usually ring-shaped but can look different on the face, neck or scalp. It may look red on lighter skin and grey or brown on darker skin ^{[1, 2]}. The rash may grow, spread or appear in more than one place, and on the scalp or face it can cause patchy hair loss ^[1].

Athlete's foot usually causes itchy white patches between the toes, with sore, flaky or red skin, cracking that may bleed, and sometimes blisters on the soles or sides of the feet. Redness can be harder to see on brown or black skin ^[4]. If left untreated it can spread to the toenails ^[4].

Nail infections cause discolouration, thickening and brittleness, and affect toenails much more often than fingernails ^[2].

3. How it spreads and who is at risk

The fungi spread through ^{[1, 2, 4]}:

• skin contact with an infected person or animal
• shared towels, bedsheets, combs, socks, shoes or sports gear
• damp shared floors, such as changing rooms and public showers
• less commonly, infected soil

Risk is higher with wet or sweaty feet, tight shoes and socks, damaged skin, contact sports and close contact with infected animals. A weakened immune system also increases risk and can make infection harder to clear ^{[2, 4]}.

4. Diagnosis

Ringworm can look like other skin and nail conditions, so testing helps make sure treatment is correct. A provider may take a small skin scraping or a nail sample ^[2]. A doctor may also take a skin sample for athlete's foot that has not responded to pharmacy treatment ^[4].

5. Treatment

Treatment depends on where the infection is and how severe it is ^[2]. The sources describe these groups ^{[1, 3, 4]}:

• Skin: antifungal creams, gels, sprays or powders from a pharmacy, used for a few weeks. The NHS advises finishing the full course even if the rash clears, and checking the label or asking a pharmacist because some products are not suitable for everyone, such as children ^{[1, 4]}. The CDC gives a typical length for skin infection of 2 to 4 weeks ^[3].
• Scalp: creams, lotions and powders are not effective, so prescription antifungal tablets and a medicated shampoo are needed. The CDC gives about 1 to 3 months of tablets ^{[1, 3]}.
• Nails: early treatment works best. Prescription antifungal tablets are usually the main option, and a provider may sometimes remove the infected nail. Treatment can take several months to a year, and nail infections can return ^[3].

An important warning from the CDC is not to use steroid creams on a rash that could be ringworm, because steroids can make the infection worse and change how it looks ^{[2, 3]}.

A child can usually go to school or nursery once treatment has started, but teachers should be told ^[1]. You do not need to stay off work or school for athlete's foot ^[4].

6. Prevention and self-care

The NHS and CDC recommend ^{[1, 2, 4]}:

1. Start treatment early to stop the infection spreading.
2. Keep skin clean and dry, and dry between the toes by dabbing rather than rubbing.
3. Wear clean cotton socks each day and avoid shoes that make your feet hot and sweaty. Do not wear the same shoes two or three days in a row.
4. Wear flip-flops or sandals in shared showers and changing rooms.
5. Do not share towels, socks, shoes, combs, bedsheets or sports gear, and wash towels and bedsheets regularly.
6. Wash your hands after touching pets, animals or soil, and keep nails short and clean.
7. Do not scratch the rash, which can spread it.
8. Take a pet to the vet if it has patches of missing fur.

Keep up these habits after treatment finishes to lower the chance of the infection returning ^[4].

7. Special groups

People with diabetes or a weakened immune system, for example during chemotherapy or after an organ transplant, should see a doctor for suspected fungal infections, because foot problems can be more serious and infection can be harder to clear ^{[1, 4]}. The CDC notes that people with diabetes have a higher risk of nail infection returning ^[3].

8. When to see a doctor

The NHS advises speaking to a pharmacist first if you think you have ringworm. They will tell you if you should see a doctor ^[1]. See a GP, a family doctor, if ^{[1, 3, 4]}:

• the rash has not improved after the pharmacist's treatment
• the infection is on your scalp or nails
• you have significant foot pain
• the foot or leg becomes hot, painful and red, which could signal a more serious infection
• the infection spreads to other parts of the body
• you have diabetes or a weakened immune system

The CDC also advises seeing a provider for symptoms that are severe, widespread or do not improve with treatment ^[3].

In an emergency, call your local emergency number (112 in India, 911 in the United States).

9. Conclusion

Ringworm and athlete's foot are common fungal infections that spread through contact and shared items. Treatment depends on the body site, and steroid creams should be avoided on a rash that could be ringworm. Good foot and skin hygiene lowers the risk, and a pharmacist or doctor can confirm the problem and guide treatment.