The skin protects us from the outside world and from harmful microorganisms. Certain fungi however, can infect the outer layer of the skin, which can lead to tinea pedis or athlete’s foot. What causes such an infection and what are the risk factors?
What is happening in the outer layer of the skin?
Dermatophytes are fungi that live in the dead outer layer of the skin. This superficial skin layer cornifies: the cells slowly dry out and die. This cornification or keratinisation of the skin is normal. The skin forms a hard, protective layer against the outer world.
The outer layer of the skin contains keratin; a protein that ensures the skin is tough and water-repellent. Fungi colonise these keratinized tissues and survive thanks to the nutrients they get from the keratin. During this process, there may be an inflammation caused by the skin’s reaction to the generated waste materials. This skin infection can cause tinea pedis also known as athlete’s foot.
The most common fungus that causes athlete’s foot in humans is Trichophyton rubrum. The fungus is highly contagious and can be spread by direct contact with the skin or the hair of an infected host. Indirect contact with contaminated clothing or surfaces will also make the fungus spread easily.
When are you at risk?
To survive and grow, the fungus needs heat and humidity. An increased risk of infection exists upon exposure to heat and moist environments. Sports enthusiasts are likely to suffer from athlete’s foot as they wear trainers during their workouts, allowing heat and moisture to accumulate. The humid environment of a swimming pool is also a risk factor as dermatophytes can resist the chlorine in swimming pools.
If you’ve suffered from athlete’s foot in the past then you are more susceptible to infection. It’s interesting that it is more likely to occur in adults than in children, in men than in women and in people with diabetes or a weakened immune system. You are also more susceptible to the infection if you suffer from excessive sweating.
How can you treat athlete’s foot?
Even if you’re not particularly sporty, you could still be at risk of getting athlete’s foot. Discover our top ten tips to help prevent future flare-ups and ways in which you can treat athlete’s foot effectively.
- Grumbt, M. et al., 2013. Keratin Degradation by Dermatophytes Relies on Cysteine Dioxygenase and a Sulfite Efflux Pump. Journal of Investigative Dermatology, 133(6), pp.1550–1555.
- Ramsey, J.P. et al., 2015. The cutaneous bacterium Janthinobacterium lividum inhibits the growth of Trichophyton rubrum in vitro. International journal of dermatology, 54(2), pp.156–9.