What are fungal infections of the skin?

Fungi are a type of naturally occurring infectious organism that can lead to a superficial infection in our skin, hair and nails.

Many fungi are environmental, living in vegetation, soil and water and don’t often cause disease in humans, but can infect animals such as wild / domesticated animals and pets. These infections can then spread to humans if we are in contact with the infected animal. Other fungal species only live on and infect humans and are passed between us.

Fungi can be thread-like so called hyphae, or they can appear as round elements called yeast. As part of our normal skin flora we have some naturally occurring yeast on our skin such as candida and malassezia.

Fungi can be passed from one person to another by direct skin to skin contact or coming into contact with fugally infected dead skin cells that have shed off onto the floor.

It can also be passed by making contact with objects in the environment around us, such as fungal elements on shared towels / hair brushes / combs / hats. If we are in contact with an animal that has a fungal infection that can occasionally pass to us as well.

Once we have a fungal infection of our feet (athletes foot) that could then spread into our nails. Living in a hot humid climate may make fungal infections more likely to occur.

Fungal infections can occur at any age, babies might get a yeast overgrowth in the nappy area (thrush or napkin dermatitis) due to candida, or they could get thrush in their mouth, this may occur due to recently being given oral antibiotics which can upset the normal balance of our skin flora (skin microbiome).

Older children at playgroup, nursery or school may get a fungal infection in their scalp called Tinea capitis – this is passed from one child to another and can pass between siblings at home.

Adults tend to suffer with athlete’s foot (Tinea pedis) which is especially common in people who have sweaty feet and those who have toes with little space between them. Sports people may also suffer from recurrent fungal infections in the groin area. Older people tend to be more likely to suffer from fungal nail infections.

Contrary to popular belief fungal infections in our skin are not associated with our diets, or allergies or stress. These infections have nothing to do with eating bread or gluten. Fungal infections are not usually associated with having diabetes.

Fungal infections of the skin can cause dry flaking skin and may feel itchy, sometimes the scaling appears in a ring-shape, hence the term ‘ring-worm’.

Between the toes fungal infections can looks like white skin that is fragile and breaks down easily.

Yeast infections often affect the skin creases (groin / under the breasts) and may look quite red with a few spots.
Fungal infections of the scalp can just present with a dry flaky scalp and sometimes a patch of hair loss.

Fungal nail infections cause thickening and discoloration of the nails (usually the big toes nails are first affected) and the nails can become quite yellow and brittle.

As with any skin condition, the history is important in terms of how the infection started and developed, and then a dermatologist should examine you.

The diagnosis may be clear after the history and examination and no investigations might be needed, however sometimes we need to take a swab and / or a scraping from skin / nails / scalp to send off the samples to the mycology (specialist fungal) lab. They may be able to identify the species of fungus for us and that can help to direct the right treatment. Sometimes we ask patients to attend the mycology laboratory in person to have samples taken by an expert mycologist who can process the sample immediately whilst you wait, this can be very helpful for speeding up the diagnosis.

Antifungal creams can be used to treat superficial fungal skin infections such as athlete’s foot, tinea in the groin area and some yeast infections, such as candida and malassezia.

Fungal hair infections respond best to antifungal tablets as the fungus actually lives inside the hair-shafts so shampoos and creams won’t clear it.

Fungal nail infections can respond to topical treatment – such as antifungal nail lacquer applied to the affected nails once per week, or we can slowly dissolve infected nail plates using a special cream. Occasionally antifungal tablets are needed for weeks or months to clear the infection properly. Discoloration in the nail plate can take a long time to grow out (as it takes 9-12 months to grow a new nail) but should clear once the infection is fully treated.

Occasionally fungal infections can recur. We are also seeing an increasing number of resistant fungal species that may require prolonged courses of high dose medication to clear them.

Overgrowth of our normal skin flora yeast can lead to patchy discoloration on the torso and that can be treated with ketoconazole shampoo to wash the skin and or some anti yeast tablets for a few weeks. The skin pigmentation may take a while to recover once the yeast overgrowth has been fully treated.