Onychoscopy in a Colombian population with a diagnosis of toenail onychomycosis: an evaluation study for this diagnostic test.

BACKGROUND

Onychoscopy is a technique that uses a dermatoscope for the evaluation of specific features of different skin conditions that are not visible to the naked eye. There are few studies establishing parameters for the diagnosis of onychomycosis based on onychoscopy. Determining the sensitivity and specificity of a potentially new diagnostic test for onychomycosis requires an evaluation study of this new diagnostic test, as there are limited studies reporting onychoscopy results.

AIM: To determine the sensitivity, specificity, positive predictive value and negative predictive value of onychoscopy findings in a Colombian population with onychomycosis.

METHODS

We assessed outpatients with a diagnosis of toenail onychomycosis confirmed by potassium hydroxide preparation or fungal culture. Onychoscopy was performed using a dermatoscope, and digital images collected using a smartphone.

RESULTS

The onychoscopy findings were: longitudinal striae, distal spiked pattern, distal irregular termination, linear edge and ruins aspect, while some patients were confirmed as having traumatic onycholysis. A statistically significant association was found between the clinical symptoms of onychomycosis and both the clinical feature of dyschromia and the onychoscopy feature of longitudinal striae.

CONCLUSION

We suggest that this technique is an alternative method that should be used in patients with onychopathies because it has the potential to differentiate onychomycosis from traumatic onycholysis and another nail involvement.