Pharmacists have a crucial role to play in identifying fungal infections and educating patients on the best course of treatment
It’s commonplace for people to visit their local pharmacy seeking treatment advice for fungal skin conditions. Be it tinea pedis, onychomycosis, tinea corporis or candidiasis, symptoms can range from irritating to unbearable.
However, effective treatment isn’t always easy to prescribe. Many products on the market have a low cure rate, but also the duration of treatment required can be notoriously long and recurrent infection is common.
While anyone can contract a fungal infection, factors that increase the likelihood include having a weak immune system, taking antibiotics, having diabetes, working in a hot humid environment, as well as having eczema or psoriasis.
Furthermore, some fungal infections (tinea, for example) are contagious. They can be spread via skin-to-skin contact or indirectly through sharing socks, towels or shoes, as well as through the use of unsterilised instruments, such as nail clippers.
The fact of the matter is fungal infections are widespread and disreputably difficult to treat. So, where does this leave the pharmacist?
Common presentations: tinea pedis and onychomycosis
Among the most common fungal infections seen in pharmacy is tinea pedis, or athlete’s foot, as it’s commonly known. The symptoms of tinea pedis include:
- scale build up or thickening skin on the soles of the feet;
- reddening of the skin (erythema);
- erosion of the interdigital and subdigital skin, mainly affecting the third and fourth toes; and itching (pruritis).
(Source: MDS Manuals. Tinea Pedis. Feb 2020)
However, before advising on treatment, it’s important to ensure you have the right diagnosis.
Dermatologist and member of the Australasian College of Dermatologists Dr Jo-Ann See explains, “It is important to note that fungal infections are really common but not everything is a fungal infection! Ideally, you have to be sure that it is tinea or a fungal infection you’re treating.
“To differentiate a fungal infection of the feet from psoriasis you may want to ask the person if they have symptoms in another place on their body. Additionally, candida can secondarily infect tinea, so bear in mind there can be two infections.
“The other important factor to acknowledge is if people have toenail fungal infection then there is a high incidence they will have a fungal infection elsewhere, such as on their feet or body.
“Therefore, if a person presents with tinea pedis, it’s important to ask the patient if they have used public showers and if they have fungal infected nails (onychomycosis, also known as tinea unguium).”
The common signs of a fungal nail infection include:
- nails that are thick, rough, or ridged;
- crumbling or flaking nails;
- discolouration—the nail appears yellow, white, brown, grey or white;
- separation of the nail from the nail bed;
- a foul odor; and
- inflammation, pain and itchiness of the surrounding tissue.
(Source: Mayo Clinic 2020; Han 2019; NHS 2017)
When it comes to differential diagnosis for onychomycosis, there are several possible alternative conditions including psoriasis of the nail, lichen planus, yellow nail syndrome, traumatic onychodystrohy and age-related nail dystrophies.
The recommended first-line treatment for tinea, excluding onychomycosis, is a topical antifungal (terbinafine 1%) applied once or twice daily for up to two weeks.
An alternative treatment is topical azoles. Drugs in this group include clotrimazole, miconazole, ketoconazole, bifonazole and econazole. Several of the products available for this class of antifungals are well priced and may be considered for infections such as mild tinea where the patient will be attentive to application frequency and duration of treatment.
It’s important that pharmacists ensure patients are aware that these products must be used once or twice daily until symptoms resolve and for up to 14 days post-resolution of symptoms. The use of bifonazole and ketoconazole is not recommended during pregnancy or breastfeeding, as the safety profile of these drugs has not been established.
Dr See advises, “Patients with tinea pedis may respond to over-the-counter antifungal creams and they may also need an antifungal powder or spray for their shoes. However, if they fail to respond to treatment it’s advisable they visit their GP, as they may have an different condition such as psoriasis or eczema.
She adds, “With regards to tinea of the groin, it’s really important to work out whether this is in fact tinea or something else like candida or psoriasis. In this case a topical combination therapy containing an anti-yeast or antifungal with a low strength topical corticosteroid may be useful.
“It would also be worthwhile asking the person if they have tinea of the foot or toenails. If the patient has a history of toenail or foot fungus then they have a greater likelihood of having tinea cruris (jock itch).
“Furthermore, if patients fail to respond to treatment then referral to the GP is warranted and it is often wise to get a fungal skin scraping or nail clipping before any further treatment is started.”
“Ideally you want to know what the fungus is, because that may give you an idea of how resistant it is. If the patient has a positive toenail clipping for fungus then an oral medication can be obtained on an authority.
“Tinea of the toenails can be really difficult to treat with low cure rates. As such, patients may require oral antifungal therapy in conjunction with topical antifungals, as well as prevention mechanisms such as spray or powder for the shoes. If patients opt for oral antifungals, it is important to advise of the potential side-effects and the fact treatment may take many months,” says Dr See.
Typically, oral antifungal therapy would be considered in the following situations:
- tinea capitis;
- widespread disease with multiple areas infected;
- failed response to topical treatment;
- immunocompromised patients
Side effects may include nausea, gastrointestinal upset, rash, myalgia, taste disturbance, hepatobiliary dysfunction and leukopenia.
“I would tend to use an oral antifungal more in the younger age group who have no other comorbidities and for people who will be adherent to the treatment, as the duration or oral therapy can range from weeks to several months,” advises Dr See.
Addressing re-infection and non-adherence
“It’s always important to consider the underlying cause of a fungal infection and offering advice on practices that may be helpful in reducing recurrent infection,” says Dr See.
Preventative measures centre on keeping the foot clean and dry and stopping the fungi from growing in the first place such as:
- washing feet regularly, especially the space between the toes, with soap and water and drying thoroughly afterwards;
- wearing sandals or thongs in public spaces where water might touch the feet, such as public showers and near swimming pools;
- washing bed sheets, socks and towels in hot water (60°C or higher) and disinfecting shoes using wipes or sprays;
- refraining from sharing socks or shoes with others; and
- changing socks when feet become sweaty.
“If patients have tinea of the body then it may be important to ask about pets, as in many cases the family pet is to blame! Asking if they could have had any direct contact with infected individuals can help them avoid re-infection.
“It is also useful to remind patients that when they’re treating themselves they need to be careful not to spread it to other family members or to other areas of their body through skin-to-skin contact.
“If they have tinea of the feet, it is worthwhile asking if they swim a lot at a swimming pool or if they go to the gym and shower there. If they intend to continue to go to the gym or swimming pool then it might be worthwhile taking a pair of thongs to use in the shower. It is really common to pick up an infection from swimming pool and gymnasium showers,” says Dr See.
“Fungal infections can be quite chronic and therefore it is important to advise the patient that treatment may be long-term. Discussing treatment duration can play a big role in supporting adherence. It is important to set patient expectations and advise them from the start how long a treatment course will be.
“There is often a high failure rate, especially with toenail infections, and usually oral treatment is required for several months. Topical treatments may require 9 to 12 months.
“Also, with toenail infections there is a high rate of recurrence and if one area is treated, such as jock itch, it may recur if the fungal reservoir, such as tinea of the feet, is not treated in conjunction,” says Dr See.
Steps that pharmacy staff can take to ensure optimal treatment include:
- Clearly explain how to use the product (when and how to apply).
- Advise on duration of product use and the importance of adherence.
- Discuss potential adverse effects (such as possible stinging on application).
- Promote ways to prevent re-infection (which is common in the case of fungal infection).
For more on this feature, including how effective is tea tree oil in treating tinea pedis, and herbal agents and fungal infections, see our March AJP print magazine and e-magazine