Determination of Association between Onychoscopy Features and Nail Plate Potassium Hydroxide Test Positivity in Diagnosis of Onychomycosis: A Cross-Sectional Study
Onychoscopy Features and Nail Plate Potassium Hydroxide Test Positivity in Onychomycosis
DOI:
https://doi.org/10.54393/pjhs.v7i8.3925Keywords:
Onychoscopy, Onychomycosis, Onychoscopic Features, Onycholysis, Jagged Edge, Potassium Hydroxide MicroscopyAbstract
Onychomycosis is a common chronic fungal infection of the nails, causing significant physical and psychological morbidity. In Pakistan, access to fungal culture and molecular diagnostics is limited, creating a need for non-invasive, rapid, and cost-effective diagnostic tools. Objectives: To determine the association between onychoscopic features and KOH positivity in clinically suspected onychomycosis. Methods: This cross-sectional study was conducted in the Department of Dermatology, Ghurki Trust and Teaching Hospital, Lahore, Pakistan, from 7 August 2025 to 10 January 2026. A total of 52 patients with clinically suspected onychomycosis were enrolled. Each patient underwent onychoscopic examination followed by nail plate potassium hydroxide (KOH) testing for fungal confirmation. Onychoscopic features, including onycholysis, jagged edge with spikes, longitudinal striae, subungual hyperkeratosis, and chromonychia, were documented. Sensitivity, specificity, predictive values, and diagnostic accuracy were calculated for each feature using KOH microscopy as the reference standard. Results: KOH test was positive in 82.7% of cases. Onycholysis had the highest sensitivity (86.1 %) while jagged edge with spikes demonstrated the highest specificity (88.9%). Onycholysis was significantly associated with KOH positivity (p=0.026), and jagged edge with spikes also showed a highly significant association (p=0.002). The combination of jagged edge and onycholysis yielded an accuracy of 76.9%. Chromonychia (p=0.160) and longitudinal striae (p=0.716) showed weaker associations. Conclusions: Specific onychoscopic features, particularly jagged edges with spikes and onycholysis, demonstrated a significant association with KOH positivity. However, given variability in sensitivity and specificity, these findings should be interpreted alongside confirmatory testing (culture or PCR, where available) rather than as standalone diagnostic criteria.
References
González Cortés LF, Prada L, Bonilla JD, Gómez Lopez MT, Rueda LJ, Ibañez E. Onychoscopy in a Colombian Population with a Diagnosis of Toenail Onychomycosis: An Evaluation Study for This Diagnostic Test. Clinical and Experimental Dermatology. 2021 Dec; 46(8): 1427-33. doi: 10.1111/ced.14706. DOI: https://doi.org/10.1111/ced.14706
Ma Y, Ji Y, Cen W, Qiao Z, Gao Y, He L, Feng W. Assessment of the Clinical Diagnosis of Onychomycosis by Dermoscopy. Frontiers in Surgery. 2022 Mar; 9: 854632. doi: 10.3389/fsurg.2022.854632. DOI: https://doi.org/10.3389/fsurg.2022.854632
Gupta AK, Wang T, Polla Ravi S, Mann A, Lincoln SA, Foreman HC et al. Epidemiology of Onychomycosis in the United States Characterized Using Molecular Methods, 2015–2024. Journal of Fungi. 2024 Sep; 10(9): 633. doi: 10.3390/jof10090633. DOI: https://doi.org/10.3390/jof10090633
Abdallah NA, Said M, Mahmoud MT, Omar MA. Onychomycosis: Correlation between the dermoscopic patterns and fungal culture. Journal of Cosmetic Dermatology. 2020 May; 19(5): 1196-204. doi: 10.1111/jocd.13144. DOI: https://doi.org/10.1111/jocd.13144
Khan SA, Shamsuzzaman SM, Rahman AK, Ashekin NA, Mahmud R, Sharmin R et al. Isolation and Identification of Dermatophytes Causing Dermatophytosis at a Tertiary Care Hospital in Bangladesh. Archives of Clinical and Biomedical Research. 2021; 5(3): 437-51.
Sipra MW, Jillian KS, Batool T. Performance Evaluation of Rapid Test Potassium Hydroxide for the Diagnosis of Onychomycosis. The Professional Medical Journal. 2021 Nov; 28(12): 1793-6. doi: 10.29309/TPMJ/2021.28.12.6215. DOI: https://doi.org/10.29309/TPMJ/2021.28.12.6215
Iorizzo M, Piraccini BM, Alessandrini A, Bruni F, Vollono L, Pampaloni F et al. Clinical and Onychoscopy Patterns in Fingernail Onychomycosis: A Study by the International Dermoscopy Society" Trichoscopy and Onychoscopy" Task Force. Dermatology Practical and Conceptual. 2025; 15(1): 1-6. doi: 10.5826/dpc.1501a4887. DOI: https://doi.org/10.5826/dpc.1501a4887
Subathra N and Santhose NB. Evaluation of Diagnostic Efficacy of Two Different Microscopic Techniques and Fungal Culture in Onychomycosis. National Journal of Laboratory Medicine. 2017; 6(3): 5.
Kim YJ, Han SS, Yang HJ, Chang SE. Prospective, Comparative Evaluation of a Deep Neural Network and Dermoscopy in the Diagnosis of Onychomycosis. Plos One. 2020 Jun; 15(6): e0234334. doi: 10.1371/journal.pone.0234334. DOI: https://doi.org/10.1371/journal.pone.0234334
Chetana K, Menon R, David BG. Onychoscopic Evaluation of Onychomycosis in a Tertiary Care Teaching Hospital: A Cross‐Sectional Study from South India. International Journal of Dermatology. 2018 Jul; 57(7): 837-42. doi: 10.1111/ijd.14008. DOI: https://doi.org/10.1111/ijd.14008
Lin YC, Sun PL, Hsiao PF, Sun FJ, Wu YH. Methods for Diagnosing Onychomycosis: A Comparative Study of 459 Cases. Dermatologica Sinica. 2019 Apr; 37(2): 63-6. doi: 10.4103/ds.ds_6_18. DOI: https://doi.org/10.4103/ds.ds_6_18
Lipner SR and Scher RK. Onychomycosis: Clinical Overview and Diagnosis. Journal of the American Academy of Dermatology. 2019 Apr; 80(4): 835-51. doi: 10.1016/j.jaad.2018.03.062. DOI: https://doi.org/10.1016/j.jaad.2018.03.062
Shakthi R, Venkatesha D. Comparison of KOH, Calcofluor White, and Fungal Culture in the Diagnosis of Onychomycosis. International Journal of Current Microbiology and Applied Sciences. 2019; 8: 1420-5. doi: 10.20546/ijcmas.2019.807.169. DOI: https://doi.org/10.20546/ijcmas.2019.807.169
Ankad BS, Gupta A, Alekhya R, Saipriya M. Dermoscopy of Onycholysis Due to Nail Psoriasis, Onychomycosis, and Trauma: A Cross-Sectional Study in Skin of Color. Indian Dermatology Online Journal. 2020 Sep; 11(5): 777-83. doi: 10.4103/idoj.IDOJ_475_19. DOI: https://doi.org/10.4103/idoj.IDOJ_475_19
Nada EE, El Taieb MA, El-Feky MA, Ibrahim HM, Hegazy EM, Mohamed AE et al. Diagnosis of Onychomycosis Clinically by Nail Dermoscopy Versus Microbiological Diagnosis. Archives of Dermatological Research. 2020 Apr; 312(3): 207-12. doi: 10.1007/s00403-019-02008-6. DOI: https://doi.org/10.1007/s00403-019-02008-6
Bhat YJ, Mir MA, Keen A, Hassan I. Onychoscopy: An Observational Study in 237 Patients from the Kashmir Valley of North India. Dermatology Practical and Conceptual. 2018 Oct; 8(4): 283. doi: 10.5826/10.5826/dpc.0804a06. DOI: https://doi.org/10.5826/10.5826/dpc.0804a06
Litaiem N, Mnif E, Zeglaoui F. Dermoscopy of Onychomycosis: A Systematic Review. Dermatology Practical and Conceptual. 2023 Jan; 13(1): e2023072. doi: 10.5826/dpc.1301a72. DOI: https://doi.org/10.5826/dpc.1301a72
Hazarika N, Chauhan P, Kansal NK, Bahurupi YA. Onychoscopy: A Quick and Effective Tool for Diagnosing Onychomycosis in a Resource-Poor Setting. Acta Dermatovenerologica Alpina, Pannonica et Adriatica. 2021 Jan; 30(1): 11-5. doi: 10.15570/actaapa.2021.3. DOI: https://doi.org/10.15570/actaapa.2021.3
Lim SS, Hui L, Ohn J, Cho Y, Oh CC, Mun JH. Diagnostic Accuracy of Dermoscopy for Onychomycosis: A Systematic Review. Frontiers in Medicine. 2022 Oct; 9: 1048913. doi: 10.3389/fmed.2022.1048913. DOI: https://doi.org/10.3389/fmed.2022.1048913
Kaynak E, Göktay F, Güneş P, Sayman E, Turan D, Baygül A et al. The Role of Dermoscopy in the Diagnosis of Distal Lateral Subungual Onychomycosis. Archives of Dermatological Research. 2018 Jan; 310(1): 57-69. doi: 10.1007/s00403-017-1796-2. DOI: https://doi.org/10.1007/s00403-017-1796-2
Shavandi A, Silva TH, Bekhit AA, Bekhit AE. Keratin: Dissolution, Extraction and Biomedical Application. Biomaterials Science. 2017; 5(9): 1699-735. doi: 10.1039/C7BM00411G. DOI: https://doi.org/10.1039/C7BM00411G
Lipner SR, Falotico JM, Konda A. Based on Sex: Impact and Treatment of Toenail Onychomycosis in Female Patients. The Journal of Clinical and Aesthetic Dermatology. 2023 Oct; 16(10): 52.
Yorulmaz A and Yalcin B. Dermoscopy as a First Step in the Diagnosis of Onychomycosis. Advances in Dermatology and Allergology. 2018 Jun; 35(3): 251-8. doi: 10.5114/ada.2018.76220. DOI: https://doi.org/10.5114/ada.2018.76220
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2026 Pakistan Journal of Health Sciences
This work is licensed under a Creative Commons Attribution 4.0 International License.
This is an open-access journal and all the published articles / items are distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. For comments
