Treatment of onychomycosis in an era of antifungal resistance: Role for antifungal stewardship and topical antifungal agents.

A growing body of literature has marked the emergence and spread of antifungal resistance among species of Trichophyton, the most prevalent cause of toenail and fingernail onychomycosis in the United States and Europe. We review published data on rates of oral antifungal resistance among Trichophyton species; causes of antifungal resistance and methods to counteract it; and in vitro data on the role of topical antifungals in the treatment of onychomycosis. Antifungal resistance among species of Trichophyton against terbinafine and itraconazole-the two most common oral treatments for onychomycosis and other superficial fungal infections caused by dermatophytes-has been detected around the globe. Fungal adaptations, patient characteristics (e.g., immunocompromised status; drug-drug interactions), and empirical diagnostic and treatment patterns may contribute to reduced antifungal efficacy and the development of antifungal resistance. Antifungal stewardship efforts aim to ensure proper antifungal use to limit antifungal resistance and improve clinical outcomes. In the treatment of onychomycosis, critical aspects of antifungal stewardship include proper identification of the fungal infection prior to initiation of treatment and improvements in physician and patient education. Topical ciclopirox, efinaconazole and tavaborole, delivered either alone or in combination with oral antifungals, have demonstrated efficacy in vitro against susceptible and/or resistant isolates of Trichophyton species, with low potential for development of antifungal resistance. Additional real-world long-term data are needed to monitor global rates of antifungal resistance and assess the efficacy of oral and topical antifungals, alone or in combination, in counteracting antifungal resistance in the treatment of onychomycosis.

Number of Affected Nails Is the Primary Determinant of Efinaconazole 10% Solution Usage for Onychomycosis.

Good adherence to treatment is necessary for the successful treatment of onychomycosis and requires that an appropriate amount of medication be prescribed. Most prescriptions for efinaconazole 10% solution, a topical azole antifungal, are for 4 mL per month but there are no data on patient factors or disease characteristics that impact how much medication is needed. Data from two phase 3 studies of efinaconazole 10% solution for the treatment of toenail onychomycosis were pooled and analyzed to determine monthly medication usage based on the number of affected toenails, percent involvement of the target toenail, body mass index (BMI), and sex. Participants with two or more affected nails required, on average, >4 mL of efinaconazole per month, with increasing amounts needed based on the number of nails with onychomycosis (mean: 4.39 mL for 2 nails; 6.36 mL for 6 nails). In contrast, usage was not greatly impacted by target toenail involvement, BMI, or sex. Together, these data indicate that the number of affected nails should be the major consideration when determining the monthly efinaconazole quantity to prescribe. J Drugs Dermatol. 2024;23(2):110-112.    doi:10.36849/JDD.7676.

Expert Consensus on Nail Procedures and Selection of CPT Codes.

BACKGROUND: Dermatologists specialize in treating conditions of the skin, hair, and nails; however, it is our experience that the field of nail diseases is the least discussed facet of dermatology. Even less acknowledged is the complexity of nail procedures and how best to accurately code for these procedures. OBJECTIVE: To convene a panel of experts in nail disease to reach consensus on the most accurate and appropriate Current Procedural Terminology (CPT) codes associated with the most commonly performed nail procedures. METHODS: A questionnaire including 9 of the most commonly performed nail procedures and potential CPT codes was sent to experts in the treatment of nail disease, defined as those clinicians running a nail subspecialty clinic and performing nail procedures with regularity. A conference call was convened to discuss survey results. RESULTS: Unanimous consensus was reached on the appropriate CPT codes associated with all discussed procedures. LIMITATIONS: Although this article details the most commonly performed nail procedures, many were excluded and billing for these procedures continues to be largely subjective. This article is meant to serve as a guide for clinicians but should not be impervious to interpretation in specific clinical situations. CONCLUSION: Billing of nail procedures remains a practice gap within our field. The authors hope that the expert consensus on the most appropriate CPT codes associated with commonly performed nail procedures will aid clinicians as they diagnose and treat disorders of the nail unit and encourage accurate and complete billing practices.

Therapeutic Recommendations for the Treatment of Toenail Onychomycosis in the US.

BACKGROUND: Onychomycosis affects around 14% of individuals in North America and Europe and is undertreated. Treatment is challenging as toenail growth can take 12–18 months, the nail plate may prevent drug penetration, and disease recurrence is common. National guidelines/consensus documents on onychomycosis diagnosis and treatment were last published more than 5 years ago and updated medical guidance is needed. METHODS: This document aims to provide recommendations for the diagnosis and pharmaceutical treatment of toenail onychomycosis following a roundtable discussion with a panel of dermatologists, podiatrists, and a microbiologist specializing in nail disease. RESULTS: There was a general consensus on several topics regarding onychomycosis diagnosis, confirmatory laboratory testing, and medications. Onychomycosis should be assessed clinically and confirmed with microscopy, histology, and/or culture. Terbinafine is the primary choice for oral treatment and efinaconazole 10% for topical treatment. Efinaconazole can also be considered for off-label use for maintenance to prevent recurrences. For optimal outcomes, patients should be counseled regarding treatment expectations as well as follow-up care and maintenance post-treatment. CONCLUSIONS: This article provides important updates to previous guidelines/consensus documents to assist dermatologists and podiatrists in the diagnosis and treatment of toenail onychomycosis. J Drugs Dermatol. 2021;20(10):1076-1084. doi:10.36849/JDD.6291.

Isolated nail lichen planus: An expert consensus on treatment of the classical form.

Lichen planus is a benign inflammatory disorder of unknown etiology that may affect the skin, mucosae, scalp, and nails. When the nails are affected, it may lead to permanent destruction with severe functional and psychosocial consequences. Therefore, prompt diagnosis and early treatment are essential, even in mild cases. There are currently no guidelines for the management of nail lichen planus and the published literature on treatment is limited. The aim of this review is to provide practical management recommendations for the classical form of nail lichen planus, especially when restricted to the nails. Topical treatment has poor short-term efficacy and may cause long-term side effects. Instead, intralesional and intramuscular triamcinolone acetonide should be considered first-line therapies. Oral retinoids are second-line choices, and immunosuppressive agents may also be considered.

Topical antifungal treatment prevents recurrence of toenail onychomycosis following cure.

Recurrence rates are high for onychomycosis, with prophylactic topical antifungal use proposed to counter recurrence. Although this is a reasonable action for many clinicians, few studies have been conducted on the efficacy of topical prophylaxis. A retrospective chart review (2010-2015) was conducted in patients receiving oral terbinafine or itraconazole for toenail onychomycosis. Following complete cure, a topical antifungal (amorolfine, bifonazole, ciclopirox olamine, or terbinafine spray) was used weekly as prophylaxis. Recurrence was recorded along with patient characteristics including demographics and concomitant medical conditions. Data from 320 patients were collected. Recurrence was significantly lower in patients receiving topical antifungal prophylaxis than in no prophylactic treatment following oral terbinafine (p < .001), but not itraconazole (p = .185). Regardless of oral treatment, the use of topical antifungals as prophylaxis (p < .001) decreased, and the number of affected toenails (p = .048) and family history of fungal infections (p < .001) increased the likelihood that recurrence would occur. This study supports the use of topical antifungal medications as prophylactic treatment to help prevent recurrence of toenail onychomycosis and suggests that those with a family history of fungal infections should be closely monitored.

Mississippi Perspective: Dermatologic Manifestations of Arsenic Poisoning.

A Mississippi perspective on arsenic poisoning is largely related to thousands of asthma patients cared for by one physician, Elmer D. Gay, MD, in the 1950s. The general medical uses of arsenic and its specific use in intractable asthma are reviewed along with the dermatologic manifestations of arsenic poisoning.

Beau lines, onychomadesis, and retronychia: A unifying hypothesis.

Beau lines, onychomadesis, and retronychia are nail dystrophies with distinctive clinical findings. Trauma has been reported as the initiating factor in each of these entities. Infections, severe medical illnesses, major surgery/anesthesia, medication side effects, and autoimmune disease can produce Beau lines and onychomadesis. This article illustrates the common underlying pathophysiological mechanism that produces each of these nail dystrophies.

Vaccine Toes Are the New COVID Toes.

Introduction: Pernio-like lesions were reported as dermatologic manifestations of COVID-19 as early as May of 2020. Since mRNA COVID-19 vaccines were introduced in December 2020, 9 reports of vaccine-associated pernio-like lesions have been presented in the medical literature. Case Presentation: A male in his 60s developed pernio-like lesions on the bilateral toes approximately 1 week after receiving the second dose of the Pfizer-BioNTech COVID-19 mRNA vaccine. His symptoms resolved in 6 weeks. Conclusion: The rising number of reports of pernio-like lesions associated with COVID-19 vaccination underlines the importance of the pathophysiological state of the vaccinated patient and how it relates to dermatological manifestations. Pernio-like lesions are thought to represent a robust host immune antiviral response related to production of interferon-1 in the setting of primary infection; incidences occurring after vaccination further support this theory. Unfortunately, media-generated reports of such reactions have the potential to inflame distrust and fear of the vaccine among the general public. Given the previous media interest in reporting pernio-like lesions with primary COVID-19 infection, it is reasonable to expect overrepresentation of pernio-like lesions with vaccination. There appears to be a general increase in patient distrust of evidence-based medicine and thus "COVID toes" represent an important intersection at which the clinician can capture the patient's trust by providing education and counseling.

Congenital Malalignment of the Great Toenail, the Disappearing Nail Bed, and Distal Phalanx Deviation: A Review.

IMPORTANCE: Congenital malalignment of the great toenail (CMGT) is an idiopathic deviation of the nail apparatus. CMGT predisposes patients to recurrent stress forces, microtrauma, and secondary complications. The purpose of this study was to review the current published photographs to determine the relationship between variants of CMGT and the disappearing nail bed (DNB). OBSERVATIONS: A search in PubMed and Google using the terms congenital malalignment of the great toenail, disappearing nail bed, and lateral nail deviation was performed. Of the 53 photographs found in a total of 35 articles, 23 were disqualified due to low picture resolution or poor angle. The remaining 30 photographs were evaluated. Pure nail malalignment with associated dystrophy and DNB was found in 22 of 30 photographs. Four of 30 cases demonstrated pure deviation of the distal phalanx, with nail dystrophy but minimal DNB. The remaining 4 cases demonstrated a combination of toe deviation and nail unit deviation with varying degrees of DNB. CONCLUSIONS AND RELEVANCE: DNB was associated with all forms of pure CMGT. Moreover, a variant of malalignment of the distal phalanx was noted in 8 photographs. This has potential implications for further studies and treatment to correct secondary complications.

Simple onycholysis.

Onycholysis may be defined as separation of the nail plate from the underlying nail bed due to disruption of the onychocorneal band. Simple onycholysis is a common condition seen in the dermatologist's office. It is not associated with inheritance, systemic diseases or drugs, dermatophyte infections, warts or neoplasms, or primary dermatologic disease such as psoriasis or lichen planus. It is generally assumed that the longer the disorder has been present, the less likely it is to resolve. As a result, we provide directions that should be given to patients presenting with simple onycholysis.

Tinea capitis caused by dermatophytes: a 15-year retrospective study from a Mississippi Dermatology Clinic.

Tinea capitis is a highly contagious disorder occurring predominantly in children. Presentation is variable and, as such, mycologic confirmation of dermatophyte infection would be useful in targeting specific therapy and implementing preventive measures to interrupt spread of infection. This retrospective study was performed at an outpatient dermatology clinic in Jackson, Mississippi, over a 15-year period (1983-1998). Dermatophyte infections were confirmed using scalp scrapings cultured on Mycosel Agar containing cycloheximide and chloramphenicol. Cultures were performed on 1220 patients of all ages presenting with signs and symptoms suggestive of tinea capitis. Of the total patients meeting the inclusion criteria, 66% were younger than 13 years. Overall, 39% (478/1220) had positive cultures for dermatophytes, with black individuals having the highest percentage of positive cultures (87% [414/478]). In addition to a review of findings, we examine the impact of a cultural diagnosis of dermatophyte infection on the treatment and prevention of this highly contagious infection.

Continuous terbinafine and pulse itraconazole for the treatment of non-dermatophyte mold toenail onychomycosis.

INTRODUCTION: Although dermatophytes are considered the predominant causative organisms in onychomycosis, non-dermatophyte mold (NDM) infections may be more prevalent than originally thought and may be more difficult to treat. There are limited data of oral antifungal efficacy in treating NDM onychomycosis. METHOD: A retrospective chart review (2009-2016) was conducted in patients receiving continuous oral terbinafine or pulse itraconazole for toenail onychomycosis due to NDMs. Mycology results and percent nail affected were recorded with patient characteristics including demographics and concurrent diseases. Complete, clinical, and mycological cure were tabulated. RESULTS: Data from 176 patients were collected. Mycological and complete cure rates for terbinafine (69.8% and 17%) and itraconazole (67.5% and 22%) were not significantly different from each other. Regardless of oral treatment, age (p = .013), baseline severity (p = .016), and presence of atherosclerosis (p = .040) or hyperlipidemia (p = .033) decreased the likelihood of mycological cure, while age decreased the likelihood of complete cure (p = .001). CONCLUSION: Continuous terbinafine and pulse itraconazole were similar in efficacy for curing NDM onychomycosis. Age was the most consistent prognostic factor affecting likelihood of cure, with factors that may influence drug reaching the site of infection also decreasing likelihood of mycological cure.

Onychomycosis in Athletes.

Onychomycosis is a common disorder that is difficult to cure. Prevalence is lower in children (0.7%), but athletes are 2.5-fold more likely to develop the disease, with infections of the toenails seven times more prevalent than those of the fingernails. This is a concern for athletes as it can interfere with their performance. The risk of developing onychomycosis is increased by the warm environment of many sports activities; the use of occlusive footwear; the warm, moist environment associated with socks and sweating; shared, close quarters among athletes; and trauma to the foot and toenail. Once infected, onychomycosis treatment requires a long duration of treatment with strict compliance, a potential problem for younger patients. Treatment carries the risk of significant side effects, and recurrence rates remain high. Avoiding infection can be a potent first line of defense and may circumvent the need for treatment. Preventive recommendations such as keeping toenails short and proper washing of laundry, to name a few, can be effective and are discussed here. Technological improvements such as synthetic, moisture-wicking socks and well-ventilated, mesh shoes have also been shown to reduce moisture and injury. Education about preventing fungal spread and improving hygiene in the locker room, gym, and pool are of critical importance. This overview of onychomycosis focuses primarily on the preventive measures and innovative changes in athletic gear. It also provides a compact step-by-step guide to prevention intended to be useful for both the general public and the professional. It can be reproduced to use as a handout for athletes, trainers, and coaches.

Ingrown toenails.

Ingrown toenails are common, especially in young patients. Several predisposing factors contribute to the formation of an irregular sharp edge (spicule) of the lateral nail plate that penetrates and injures the soft tissue of the lateral nail fold. Depending on the severity of the disease, treatment varies from simple disembedding of the spicule to phenolization of the lateral nail matrix. This article provides a step-by-step guide to the management of patients with ingrown toenails.