When fungus infects

Hit television series The Last of Us describes a post-apocalyptic world where people are affected by a zombie-like fungus that takes over their minds. While the reality of fungal infections doesn’t yet involve humans becoming zombies, the drama draws attention to the risks that such infections present to public health, and the need for further research to guide antifungal stewardship and public awareness of common fungal infections.

In 2022, the World Health Organisation published its first fungal priority pathogens list, which recognised that fungal infections are a growing risk to public health. Of concern is the emergence of pathogens that are resistant to antifungal medications.

“Invasive fungal diseases are rising overall and particularly among immunocompromised populations,” the WHO said.¹

“The diagnosis and treatment of invasive fungal diseases are challenged by limited access to quality diagnostics and treatment, as well as the emergence of antifungal resistance in many settings.

“Despite the growing concern, fungal infections receive very little attention and resources, leading to a paucity of quality data on fungal disease distribution and antifungal resistance patterns. Consequently, it’s impossible to estimate their exact burden.” ¹

Researchers are emphasising that fungi and the infections they cause are under-researched and should be an area of priority over the coming years.

“Fungi are the ‘forgotten’ infectious disease,” said Dr Justin Beardsley, from the University of Sydney’s Infectious Disease Institute, a contributor to the study group for the WHO fungal list.² “They cause devastating illnesses but have been neglected so long that we barely understand the size of the problem.

“For this project, our team of 30 researchers from across Australia and New Zealand screened over 6000 papers and recruited more than 400 international mycology experts. It was a comprehensive effort to describe current knowledge, understand what drives priorities, and allow the WHO to set an objective research agenda.”²

Fungi can grow in different kinds of environments and cause infection. When we think of fungal infections, usually unpleasant things come to mind: peeling skin, pus, and broken nails, for example. However, fungal infections can affect us all, and antifungal drugs can help by targeting structures in fungal cells to fight the infection.

Community pharmacy is a leader in treating and caring for minor fungal infections in Australia, as antifungal medications are readily available.

Common fungal infections 

Fungal infections typically affect the hair, skin and nails. Common infections caused by fungus are:

• Athlete’s foot.
• Jock itch.
• Ringworm.
• Onychomycosis, or fungal infection of the nail.
• Thrush.

Other types of fungal infections can affect the respiratory system and pose a significant risk to people with weakened immunity and asthma.

Greater risk for the immunocompromised  

Immunocompromised people such as those living with diabetes, HIV and cancer are at a greater risk of developing a fungal infection because such infections are opportunistic, meaning they will target weakened immune systems, which makes it easier for fungi to invade the body. Therefore, where customers have compromised immune systems, it’s important to look for signs of fungal infections, and if these are found, to refer them to a GP.

Types of antifungal medication 

Four classes of antifungal medications are used in clinical practice: azoles, echinocandins, pyrimidines and polyenes. These can be applied both topically and orally. Topical application is usually given only for minor fungal infections and has varying success rates, while more serious infections and those that fail to respond to topical application warrant oral medications.

Candida 

Candida is a type of fungus that naturally occurs within the body, especially in warm and moist areas. However, when in excess, it can cause fungal infections. Most commonly, Candida is responsible for thrush or yeast infection occurring when an overgrowth of Candida occurs within the body.

Thrush can affect the penis, groin, vagina and mouth.^{3<superscript>} Vaginal thrush causes itching and burning of the vagina or vulva, white vaginal discharge, pain during sex, swelling of the vagina and vulva, stinging when urinating, and splits in the skin of the vulva.

According to Jean Hailes, around 75 per cent of women will experience thrush once in their lifetime. It’s important to note that thrush is not an STI, although sexual activity can make symptoms worse.

Women will often go to the pharmacy as the first port of call for over-the-counter antifungals, usually via a cream or vaginal pessary. But if this treatment doesn’t work, it’s important to see a GP for a vaginal swab. People are at greater risk of developing vaginal thrush if they’ve recently taken antibiotics, are using a higher dose of the combined oral contraceptive pill, are pregnant, or have vulval skin conditions.^{4<superscript>}

Tinea  

Tinea is a fungal infection found in warm and moist parts of the body and is responsible for athlete’s foot, jock itch, onychomycosis and ringworm.⁵ Tinea is common among athletes and those who regularly share communal change rooms. Symptoms of tinea include a red, flaky rash that can crack, split and peel, as well as cause blistering and itching.

Tinea is contagious, so if it’s been diagnosed, it’s important to remind customers to not share towels, bathmats, flannels or footwear.²

Tinea is usually treated through creams, ointment, gel or nail lacquer, all available OTC from any pharmacy. Tinea can take weeks or even months to clear up, depending on the fungus type. Patients should keep using the antifungal medication as instructed, even if the tinea appears to have resolved. In treating tinea, the area must be kept clean and dry, as the infection prefers moist environments.

Athletes foot 

Athlete’s foot refers to when tinea affects the skin of the feet and can spread to the toenails and the hands. This is a minor fungal infection spread by contact with the fungus tinea, which can be found on surfaces such as those in showers, locker room floors, swimming pools, or through contact with a person with the fungal infection. For people with diabetes or those immunocompromised, a GP must be consulted.⁶

Athlete’s foot thrives in damp, moist and warm environments, so keeping the skin clean and changing footwear and socks are advisable for preventing contraction.

Athlete’s foot can be treated with topical over-the-counter antifungals. If these aren’t successful, a GP can prescribe oral antifungals.

Jock itch 

Jock itch is also caused by the fungus tinea and affects moist areas of the groin. It’s typically called jock itch because it usually affects people who sweat frequently, such as athletes. Jock itch causes an itchy and painful rash.⁷

Onycholysis

Onycholysis is a common disorder that occurs when tinea affects the nails. In some cases, the nails can become thickened with yellow, white or brown streaks. If the infection worsens, the nail can separate from the nail bed. If left untreated, onycholysis can deform the nail or destroy it. While onycholysis can be treated with topical medications, this can have varied success, with oral antifungals needed in most cases. The most common antifungal used for onycholysis is terbinafine, used for three to six months. When diagnosed and treated early, onycholysis usually resolves following antifungal dissemination.⁸

Ringworm 

Ringworm of the body (tinea corporis) and ringworm of the scalp (tinea capitis) is also caused by the fungus tinea.

Tinea corporis appears as an itchy red circular rash and develops on the top layer of skin. It’s contagious and can be spread through contact with people and animals. Antifungals are used to treat mild ringworm, usually through a cream. However, if the infection doesn’t clear within a week, it’s best to advise patients to see a GP.⁹

Tine capitis is the most common fungal infection affecting children, but can also affect adults. It can present in a variety of ways, such as an itchy and dry scalp with areas of hair loss, black dots in areas of hair loss, and yellow crust throughout the scalp. A severe infection can cause fever and swollen lymph glands.¹⁰

Tinea capitis is diagnosed by a doctor and involves taking a scalp scraping to confirm. When not detected early enough, it can cause permanent hair loss as well as scarring.¹⁰

Prevention 

Fungal infections are treatable and preventable. According to Healthline, maintaining good hygiene is key to avoiding fungal infections.

Fungal infections can be avoided by:

• Keeping skin clean and dry, particularly the folds of the skin.
• Washing hands often, especially after touching animals or other people.
• Avoiding using other people’s towels and other personal care products.
• Wearing shoes in locker rooms, community showers, and swimming pools.
• Wiping gym equipment before and after use.¹¹

References 

1. World Health Organisation. ‘WHO fungal priority pathogens list to guide research, development and public health action’. 2022. int/publications/i/item/9789240060241.
2. University of Sydney. ‘First WHO ‘watch list’ of health-threatening fungi released’. 2022. edu.au/news-opinion/news/2022/10/26/first-who-watch-list-of-health-threatening-fungi-released.html.
3. Health Direct. ‘Thrush’. 2021. gov.au/thrush.
4. Jean Hailes. ‘Thrush’. 2022. org.au/health-a-z/vulva-vagina-ovaries-uterus/vulval-vaginal-conditions/thrush.
5. Health Direct. ‘Tinea’. 2021. gov.au/tinea.
6. ‘Athletes foot’. 2019. healthline.com/health/athletes-foot#treatment.
7. Australasian College of Dermatologists. ‘Tinea onychomycosis’. 2019. edu.au/atoz/tinea-onychomycosis/
8. Health Direct. ‘Ringworm of the body’. 2017. gov.au/ringworm.
9. Raising Children Network. ‘Ringworm or tinea’. 2021. net.au/guides/a-z-health-reference/ringworm.
10. Australasian College of Dermatologists. ‘Tinea capitis’. 2015. edu.au/atoz/tinea-capitis/
11. ‘Everything you need to know about fungal infection’. 2019. healthline.com/health/fungal-infection#prevention

This feature was originally published in the April issue of Retail Pharmacy magazine.