Dear Editor:
Oral antifungals are considered the most effective treatment of onychomycosis (OM), however, the use of them is limited in patients with comorbidities owing to adverse drug reactions. Topical antifungals are comparatively safe but exhibit low efficacy1. Accordingly, additional safe and efficacious therapeutic options are needed, especially for patients in whom oral antifungals are restricted2. Here, we evaluated the efficacy of topical antifungals combined with grinding and drilling in patients with end-stage renal disease (ESRD). This study was approved by the Institutional Review Board of Inje University Busan Paik Hospital (IRB No. 2019-01-119). Five participants who were clinically diagnosed OM on bilateral great toenails with similar degrees of severity but had no treatment for 3 months were enrolled. For each patient with suspected OM, we randomly classified one affected great toenail as the combination therapy (CT) side and the other as the monotherapy (MT) side.
Drilling and grinding were performed only for CT side in two-month interval, but not for MT side. An automatic device (SDE-H35S + MARATHON-4; manufactured by SAEYANG Co., Ltd., Daegu, Korea) was used to grind affected portions of the nail plate. After grinding, holes (diameters, 1 mm), spaced 2 mm apart, were drilled through the nail plate (Fig. 1). Topical efinaconazole 10% nail solution (JUBLIA®; Ortho Dermatologics, Bridgewater, NJ, USA) was applied to both CT and MT side, once daily. Nails from participants were evaluated every month for 6 months from visits 1 to 7; at each visit, we obtained clinical images, and collected nail samples for mycological testing.
Fig. 1. We used an automatic device to grind affected portions of the nail plate. After grinding, holes were drilled through the nail plate.
Treatment efficacy was determined based on mycological and clinical assessments. Mycological improvement was established when both the results of the KOH examination and fungal culture were negative. OM severity index (OSI) score3 and maximum linear clear nail growth (MLCNG)4 were determined at every visit. Last clinical outcome compared to initial state was evaluated by 5-point Likert scale, termed as global photographic assessment (GPA) score in this study, which regards ‘−2’ as great aggravation, ‘−1’ as slight aggravation, ‘0’ as no change, ‘1’ as slight improvement, and ‘2’ as great improvement.
Three (60%) patients had distal lateral subungual OM (DLSO), whereas 2 (40%) patients presented with total dystrophic OM (TDO). Mean GPA score of CT and MT sides were 1.6 and 0.6, respectively, means clinical outcome was superior in CT side compared with MT side. Also, CT sides revealed significantly decreased MLCNG (p=0.038) scores when compared with those at the initial. On the MT side, however, there was no significant difference in OSI and MLCNG scores when compared with those at the initial visit (Table 1). Regarding mycological assessment, Trichophyton rubrum was identified in all nails at initial visit. After 6 months, three of five nails (60%) on the CT side presented a mycological cure; however, only one of five nails (20%) showed mycological cure on the MT side.
Table 1. Alterations in the OSI and MLCNG scores of the two groups at the visit 1 (initial) and visit 7 (6 months after treatment).
| Groups | Score | Visit 1 | Visit 7 | Δ (Visit 1 & 7) | p-value |
|---|---|---|---|---|---|
| Combination therapy | OSI | 25.6±6.4 | 13.4±10.2 | 12.2±8.2 | 0.053 |
| MLCNG | 6.4±7.1 | 15.2±3.5 | 8.8±6.8 | 0.038 | |
| Monotherapy | OSI | 25.6±6.4 | 21.6±12.0 | 3.6±6.4 | 0.552 |
| MLCNG | 5.4±7.4 | 9.6±9.2 | 3.8±9.2 | 0.510 |
Values are presented as mean ± standard deviation.
OSI: onychomycosis severity index, MLCNG: maximum linear clear nail growth.
Our study revealed that nails treated with combination therapy exhibited greater improvement than those treated with topical efinaconazole alone. This is likely attributable to the increased penetration of the topical antifungal owing to the reduced nail thickness and micropores on the nail plate5. Additionally, in patients with an initially high severity (e.g. patient No. 3), the CT side exhibited significantly higher improvement than the MT side. Thus, grinding and drilling techniques can have synergic effect with topical agent also in severe OM.
The limitations of this study were the relatively small number of patients and the short duration to the final evaluation time point. In the future, a larger, customized study is needed to better analyze the treatment efficacy of grinding and drilling.
Footnotes
FUNDING SOURCE: None.
CONFLICTS OF INTEREST: The authors have nothing to disclose.
DATA SHARING STATEMENT: Data used to support the findings of this study are available from the corresponding author upon request.
References
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