Original article
Dermoscopic patterns of fungal melanonychia: A comparative study with other causes of melanonychia

https://doi.org/10.1016/j.jaad.2016.08.013Get rights and content

Background

Diagnosing fungal melanonychia (FM) is often difficult because it mimics melanonychia caused by other factors. Dermoscopy is helpful in the setting of nail pigmentation. However, the diagnostic characteristics of FM on dermoscopy are not fully elucidated.

Objective

We sought to determine the dermoscopic characteristics of FM.

Methods

We evaluated the dermoscopic patterns of FM diagnosed at 2 university hospitals from January 2010 to February 2016. We included nail matrix melanocytic activation, nail matrix nevi, and nail unit malignant melanomas as control groups for comparison.

Results

In all, 18 FM, 24 melanocytic activation of the nail matrix, 27 nail matrix nevi, and 11 malignant melanoma cases were analyzed. Statistical analysis revealed that yellow color, multicolor pattern, nonlongitudinal homogenous pattern, reverse triangular pattern, subungual keratosis, white or yellow streaks, and scales on the nail were more frequent in FM. However, gray color, longitudinal pattern, and pseudo-Hutchinson sign were less frequent in FM than in controls.

Limitations

This was a retrospective study from 2 university hospitals, with a small sample size.

Conclusion

The results revealed distinctive dermoscopic patterns for FM. Therefore, dermoscopy can be a useful ancillary tool for diagnosing FM.

Key words

dermoscopy
fungal melanonychia
malignant melanoma
melanonychia
nail matrix nevus
onychomycosis
onychoscopy

Abbreviations used

FM
fungal melanonychia
KOH
potassium hydroxide
MM
malignant melanoma
NMN
nail matrix nevus

Cited by (0)

Supported by Research Resettlement Fund for the new faculty of Seoul National University.

Conflicts of interest: None declared.

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