ONYCHOMYCOSIS: DIAGNOSIS MADE EASY

Onychomycosis: Diagnosis made easy

Hossam Abdel-Wahab, MD¹, Walid Medhat, MD¹, Maha H Ragaie, MD¹, Fatma M Mohammed, MSc²

¹Department of Dermatology, Faculty of Medicine, Minia University, Minia, Egypt. ² Assuit Dermatology Hospital, Ministry of Health, Assuit, Egypt.

Background: Onychomycosis is the most prevalent nail disease, accounting to about 50% of all onychopathies. The diagnosis is still a challenge considering that the gold standard complementary test (direct microscopy and culture) may be false negative in many cases.

Objectives: The study aimed to evaluate the role of dermoscopy in diagnosis of onychomycosis in comparison with scrap microscopic examination, mycological culture and histopathology and to detect how close the dermoscopic examination to the previous diagnostic findings.

Patients and Methods: The present study included 20 patients suffered from onychomychosis and they were subjected to clinical, KOH microscopic, dermoscopic, mycological and histological examinations.

Results: Jagged edge with spikes, longitudinal striations, distal irregular termination and ruin appearance are dermoscopic criteria of onychomychosis observed in 75% of cases. KOH examination was positive in only 20% of patients showing spores and hyphae. Culture was positive in only 35% of cases with M. canis, T. violaceum, T. rubrum, Chaetomium sp. and Scopulariopsis brumpt and there were no difference between the dermoscopic features caused by different organisms. The histologic evaluation showed found septate hyphea and blastoconidias within the amorphous keratin of the nail in 65%.

Conclusions: Dermoscopy may be considered an easy, helpful, quite simple, quick and inexpensive technique for increasing the diagnostic accuracy of onychomycosis and could be a practical and effective diagnostic tool when mycology is not readily available. Mycology can, on the other hand, be avoided when nail dermoscopy fail to show any diagnostic sign of onychomycosis.

Keywords: Onychomychosis, Dermoscopy,  Nail biopsy, Culture, KOH scraping

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How to cite this article:
Hossam Abdel-Wahab, Walid Medhat, Maha H Ragaie, Fatma M Mohammed. Onychomycosis: Diagnosis made easy.American Journal of Dermatological Research and Reviews, 2022, 5:52. DOI: 10.28933/ajodrr-2022-04-1805e

References:

1. Baran R, Hay RJ, Tosti A and Haneke E. A new classification of onychomycosis. Br J Dermatol. 1998;139:567–71.
2. Shenoy MM, Teerthanath S and Karnaker VK. Comparison of potassium hydroxide mount and mycological culture with histopathological examination using periodic acid-Schiff staining of the nail clippings in the diagnosis of onychomycosis. Indian J Dermatol Venereol Leprol. 2008;74:226–229.
3. Abdallah NA, Said M, Mahmoud MT, Omar MA. Onychomycosis: Correlation between the dermoscopic patterns and fungal culture. J Cosmet Dermatol. 2020;19:1196–1204.
4. Behzadi P, Behzadi E and ranjbar R. Dermatophyte fungi: Introduction, diagnosis and treatment; SMU Med J. 2014;1(2): 50-62.
5. Bet DL, dos Reis AL, Di Chiacchio N, Belda Junior W. Dermoscopy and onychomycosis: guided nail abrasion for mycological samples. An Bras Dermatol. 2015;90(6):904–906.
6. El-Hoshy KH, Abdel Hay RM, El-Sherif RH, Salah Eldin M, Moussa MF. Nail dermoscopy is a helpful tool in the diagnosis of onychomycosis: a case control study. Eur J Dermatol. 2015;25(5):494–495.
7. Micali G, Lacarrubba F, Massimino D, Schwartz RA. Dermatoscopy: alternative uses in daily clinical practice. J Am Acad Dermatol. 2011;64:1135–1146.
8. Piraccini BM and Alessandrini A. Onychomycosis: A Review. J Fungi (Basel). 2015; 1(1): 30–43.
9. Piraccini BM, Balestri R, Starace M, Rech G. Nail digital dermoscopy (onychoscopy) in the diagnosis of onychomycosis. J Eur Acad Dermatol Venereol. 2013;7(4):509–513
10. De Crignis G, Valgas N, Robertha P Nakamura R (2014): Dermatoscopy of onychomycosis. Int J Dermatol. 2014;53(2):97-9.
11. Jesús-Silva MA, Fernández-Martínez R, Roldán-Marín R, Arenas R. Dermoscopic patterns in patients with a clinical diagnosis of onychomycosis-results of a prospective study including data of potassium hydroxide (KOH) and culture examination. Dermatol Pract Concept. 2015 Apr 30;5(2):39-44.
12. Wilsmann-Theis D, Sareika F, Bieber T, Schmid-Wendtner MH, Wenzel J. New reasons for histopathological nail-clipping examination in the diagnosis of onychomycosis. J Eur Acad Dermatol Venereol. 2011;25(2):235-7.
13. Bombace F, Iovene MR, Galdiero M, Martora F, Nicoletti GF, D’Andrea M, Della Pepa ME, Vitiello M. Non-dermatophytic onychomycosis diagnostic criteria: an unresolved question. Mycoses. 2016;59(9):558-65.
14. Nada EEA, El Taieb MA, El-Feky MA, Ibrahim HM, Hegazy EM, Mohamed AE, El-Amir MI. Diagnosis of onychomycosis clinically by nail dermoscopy versus microbiological diagnosis. Arch Dermatol Res. 2020;312(3):207-212.
15. Jeelani S, Ahmed QM, Lanker AM, Hassan I, Jeelani N, Fazili T. Histopathological examination of nail clippings using PAS staining (HPE-PAS): gold standard in diagnosis of onychomycosis. Mycoses. 2015;58(1):27–32
16. Alkhayat H, Al-Sulaili N, O’Brien E, McCuaig C, Watters K. The PAS stain for routine diagnosis of onychomycosis. Bahrain Med Bull. 2009;31:1–8
17. Gupta AK, Paquet M, Simpson FC. Therapies for the treatment of onychomycosis. Clin Dermatol. 2013;31(5):544–554.