Treating Fungal Infections In Patients With Wounds

Fungal infections can exacerbate the already compromised environment of lower extremity wounds. These expert panelists discuss treating fungal infections in wound care patients, offering insights on oral treatments, topical therapies, and the potential of lasers.

Q:

Do you treat fungal skin and nail disease in lower extremity wound patients?

A:

For Brent Haverstock, DPM, the decision to treat is based on whether he feels the infection is contributing to the wound. He notes that a large number of his patients who present with lower extremity wounds are quite compromised medically and have onychomycosis. Some of his patients also present with features typical of a mycotic skin infection such as a region of chronic erythema with associated pruritus. Dr. Haverstock says such patients often demonstrate the classical moccasin distribution on the plantar aspect of the foot. If Dr. Haverstock suspects a mycotic infection in the wound, he will culture by sending a piece of tissue from the wound.

   Bryan Markinson, DPM, says most of his wound patients have diabetes or vascular insufficiency. In this population, he says neglected fungal infections of the skin result in skin breaks that can be a portal for infection by bacteria, which can greatly complicate matters. Therefore, Dr. Markinson aggressively treats tinea infections.

   Similarly, Kazu Suzuki, DPM, CWS, has found that fungal skin and nail disease contribute to foot ulcers and amputations. He has amputated many toes and feet over the years because of the injuries caused by dystrophic fungal nails or tinea pedis. When it comes to patients with diabetes and/or peripheral arterial disease, Dr. Suzuki says interdigital tinea pedis or severe skin fissures exacerbated by tinea pedis can be dangerous as they can lead to skin breakdown, cellulitis and limb-threatening infection.

   Noting that wound care patients are no different than any patient with a fungal infection, John Mozena, DPM, treats the infection before it spreads to other areas of the body or to other people. He always offers patients treatment for their fungal infection depending on its severity. His treatment options include topicals, orals, laser fungus ablation, nail removal and conservative therapy.

Q:

Do you obtain a fungal or yeast culture when treating fungal skin and nail diseases?

A:

Dr. Mozena points out controversies over culturing fungal infections, asserting that many podiatrists believe their clinical experience is adequate in making a diagnosis. Furthermore, he notes that fungal cultures are only 75 percent reliable and can give a false positive or negative result in many cases.1

   Dr. Mozena notes that patients are reluctant to pay for a test that is unreliable. He adds that the most reliable tests, periodic acid Schiff (PAS) and polymerase chain reaction, are very expensive. With that said, he still offers testing to every patient using oral antifungal or laser treatment, and lets patients decide whether they would like a culture taken or not.

   Before Dr. Haverstock begins therapy, he obtains a KOH and fungal culture. If the KOH examination is positive for fungal hyphae and he is concerned that this is affecting the progression of wound healing, Dr. Haverstock will proceed with therapy.

   However, Drs. Suzuki and Markinson do not routinely culture. Dr. Suzuki feels taking a medical history is often sufficient to exclude diseases such as psoriasis and other conditions that mimic fungal skin and nail disease.

   Dr. Markinson treats most fungal infections empirically. If the patient does not respond to topical therapy, he believes a skin biopsy is the best diagnostic procedure. As he notes, one can get a PAS stain on the tissue as well as determine if the patient has a steroid responsive dermatitis, which is very common with venous disease. If Dr. Markinson is treating nail disease, he mostly uses oral terbinafine (Lamisil, Novartis) and never treats nail disease before obtaining a confirmatory culture or positive PAS stain.

Q:

What is your fungal treatment of choice (topical/oral) in patients with wounds?

A:

Drs. Suzuki, Markinson and Haverstock use various iterations of terbinafine. For nail treatment, Dr. Markinson will use oral terbinafine, 250 mg daily for seven days, which patients repeat every three months for a total of four pulses.2 He says his results have shown the same success as in the study by Zaias and Rebell. In between pulses, the patient has a two-month and three-week drug holiday, which he says virtually eliminates hepatotoxicity concerns. This also eliminates the need for a hepatic profile during therapy, which he would normally do. Dr. Markinson always gets a liver profile and blood count before therapy begins.

   For topical antifungal treatment of skin and nail disease, Dr. Suzuki recommends QD to BID applications of over-the-counter terbinafine spray, calling it easier to apply in comparison to creams and citing its ready availability. If the patient does not respond clinically to terbinafine after a few weeks, he may prescribe other antifungal medications such as ciclopirox (Loprox, Medicis) or sertaconazole (Ertaczo, OrthoDermatologics).

   Clinically, if Dr. Haverstock suspects a fungal infection of the skin, he starts the patient on a topical medication such as terbinafine hydrochloride. If the patient has a positive response, he continues using terbinafine until the infection has resolved. If a wound culture demonstrates a fungal infection, Dr. Haverstock consults infectious disease specialists to assist in treating the infection. He relies heavily on infectious disease consultants when managing these infections.

   As for oral antifungal medications, Dr. Suzuki prefers terbinafine, 250 mg QD for two weeks for skin disease and three months for nail disease. He obtains a liver function panel and complete blood count prior to prescribing three-month oral therapy in order to rule out any liver dysfunction. Itraconazole (Sporanox, Janssen Pharmaceuticals) 200 mg PO QD for three months is another choice for onychomycosis treatment. However, he notes it is less preferable because of the drug interaction and the black box warning for patients with congestive heart failure.

   Drs. Markinson and Haverstock cite the use of ciclopirox. For tinea pedis, Dr. Markinson typically uses ciclopirox cream 0.77%. His patients get a 90 gram tube with six refills and instructions to use it daily after showering. He will also introduce to the patient the concept of lifelong prophylaxis with this regimen. Dr. Markinson rarely uses an oral agent for tinea pedis. For nail infections, Dr. Haverstock uses topical ciclopirox 8% nail lacquer.

   Dr. Mozena offers each patient all options for fungal treatment. He will also discuss the range of success rates noted in the literature for each modality. As he points out, topicals are 5 to 50 percent effective depending on the study and the definition of success.3 He also notes that orals have a 14 to 75 percent success rate for onychomycosis and laser studies have shown a 65 to 85 percent clinical response rate for onychomycosis.4,5 He explains to patients that a response rate means their condition can have a response from 1 to 100 percent, depending on many factors.

Q:

What is your opinion on laser therapy for fungal nails?

A:

In the future, Dr. Mozena feels laser treatment will be the standard of care for tinea unguium. He acknowledges that there are several ongoing studies for lasers and more are needed. Drs. Haverstock and Markinson also cite a need for more research.

   Although lasers for onychomycosis show “exciting promise,” Dr. Markinson notes a paucity of data. He feels the laser has a rightful place in the long-term management of onychomycosis.

   “If ethically promoted this way, and not as a ‘zap’ cure or described as the ‘most effective’ treatment, only then will its true value be realized and the degree of efficacy be determined,” he cautions.

   Likewise, Dr. Suzuki feels the burden is on the laser device companies to provide a large-scale randomized controlled trial to establish clinical evidence and determine if the treatment is “vastly superior” over placebo or a control group.

   Dr. Suzuki cites the advantages of having lasers as an alternative therapy to systemic antifungal therapy, which may interact with other medications or potentially cause liver injury. Furthermore, Dr. Haverstock acknowledges that lasers have a much better safety profile than oral medication, particularly in patients with chronic wounds. Such wound care patients usually have multiple medical problems and are on a number of medications, according to Dr. Haverstock. He says adding an oral antifungal agent to an already compromised patient has a risk that he believes is not worth the potential outcome.

   Dr. Suzuki feels laser onychomycosis therapy would take off if it had its own CPT code or even a partial insurance reimbursement.

   “At this moment, I have referred many patients for laser therapy to my colleague in my institution, but many of my patients seem to have second thoughts when they hear that the treatment is still cash-only and is neither quick nor a permanent ‘cure’ of fungal nails,” notes Dr. Suzuki.

   Dr. Mozena also acknowledges several questions on lasers for antifungals. Is the dual wavelength or single wavelength treatment best? Is the pulse duration or cavitations critical in killing the fungus? Is 1064 nm the right wavelength? Is spot size or the number of passes the most important factor? Can combination therapy prove more efficacious for fungus treatment?

   “All these factors need to be explored before we dismiss or proceed with this exciting new technology,” says Dr. Mozena.

Q:

Do you have any additional clinical pearls on treating fungal infections in patients with wounds?

A:

Dr. Haverstock supports performing routine debridement of the nails when treating nail fungal infections. He prefers using a nail drill to allow deep penetration of the medication. As he notes, the results are “much more impressive” when one debrides the nails every three to four weeks.

   Dr. Markinson advises podiatrists never to start oral or laser therapy for onychomycosis without absolute laboratory confirmation of a dermatophyte infection.

   “Although many do not agree and feel they can diagnose clinically, the legal ramifications of an adverse event with either therapy without laboratory confirmation are simply and unequivocally indefensible,” he says.

   Dr. Suzuki recommends using a free drug database that is available to you and your assistant at all times. He uses Epocrates (https://www.epocrates.com ) software, which is available on iPhones and online. With that free app, he says one can check for the correct dosing and drug-to-drug interactions as well as adverse reactions, pricing and pill pictures. He also recommends Medscape (https://www.medscape.com ), which also has a similar drug database and a smartphone app that is free of charge.

   Dr. Mozena says fungal disease is a constant battle between the nail trying to grow out and the fungus progressing inward. In order to address a dynamic disease, Dr. Mozena says the treatment approach should be equally dynamic.

   “We should keep an open mind to new treatment options and encourage the scientific proof of their efficacy,” he says.

   Dr. Haverstock is an Assistant Clinical Professor of Surgery and the Chief of the Division of Podiatric Surgery in the Department of Surgery at the University of Calgary. He is the Director of the Diabetic Foot and Limb Preservation Centre in Calgary. Dr. Haverstock is also a Fellow of the American Society of Podiatric Dermatology.

   Dr. Markinson is the Chief of Podiatric Medicine and Surgery in the Leni and Peter W. May Department of Orthopedic Surgery at the Mount Sinai School of Medicine in New York, N.Y. He is a Fellow of the American Society of Podiatric Dermatology.

   Dr. Mozena is in private practice at the Town Center Foot Clinic in Portland, Ore. He is a Fellow of the American College of Foot and Ankle Surgeons, and is board certified in foot and ankle surgery. He is an Associate of the Western Health Sciences University Podiatric and Surgery Department.

   Dr. Suzuki is the Medical Director of the Tower Wound Care Center at the Cedars-Sinai Medical Towers. He is also on the medical staff of the Cedars-Sinai Medical Center in Los Angeles and is a Visiting Professor at the Tokyo Medical and Dental University in Tokyo.

References

1. Scherer WP, Kinmon K. Dermatophyte test medium culture versus mycology laboratory analysis for suspected onychomycosis. A study of 100 cases in a geriatric population. J Am Podiatr Med Assoc. 2000; 90(9):450-9.
2. Zaias N, Rebell G. The successful treatment of Trichophyton rubrum nail bed (distal subungual) onychomycosis with intermittent pulse-dosed terbinafine. Arch Dermatol. 2004; 140(6):691-695.
3. Crawford F, Hollis S. Topical treatments for fungal infections of the skin and nails of the foot. Cochrane Database Syst Rev. 2007; 18(3):CD001434.
4. Iozumi K, Hattori N, Adachi M, et al. Long-term follow-up study of onychomycosis: cure rate and dropout rate with oral antifungal treatments. J Dermatol. 2001; 28(3):128-36.
5. Landsman AS, Robbins AH, Angelini PF, et al. Treatment of mild, moderate and severe onychomycosis using 870- and 930-nm light exposure. J Am Podiatr Med Assoc. 2010; 100(3):166-77.

   For further reading, see “Pertinent Insights On Diagnosing And Treating Infected Wounds” in the November 2011 issue of Podiatry Today.