Dermoscopic Patterns in Relation to the Clinicopathologic Manifestations of Leprosy

Abstract

Objectives. Leprosy is a chronic granulomatous infection caused by the obligate intracellular organism Mycobacterium  leprae. Current diagnostic tests for confirmation and treatment monitoring such as slit skin smear and biopsy are invasive and require time for processing, reading, and interpretation. Dermoscopy is a technique that allows the visualization of structures not readily seen by the naked eye. It can be performed at the point of care, providing a non-invasive link between clinical and histopathologic examination. This study aimed to determine the dermoscopic findings and associated clinicopathologic findings of the different forms of leprosy.

Methods. A cross-sectional study was conducted. All new and follow-up patients aged 19 years old and above clinically diagnosed with leprosy were invited to participate in the study during the three-month investigation period. Clinical and dermoscopic photographs of representative skin lesions were taken, and a review of slit skin smear and histopathology results was done. Data analysis was performed using Stata SE version 13. The association between dermoscopic findings and the following parameters: anatomic location, Ridley-Jopling classification, WHO classification, treatment duration, and average bacteriologic index were analyzed using Fisher’s exact test. The level of significance was set at 5%.

Results. A total of 57 lesions were included. Linear vessels (p=0.031), structureless areas (p=0.008), and globules (p=0.002) were found to be significantly associated with the anatomic location. Decreased hair was found to be significantly associated with treatment duration (p=0.038). No significant associations were found between dermoscopic findings and Ridley-Jopling classification, WHO classification, and ABI. Eight biopsies taken at the time of dermoscopy were reviewed, with all sites showing structureless or globular areas corresponding to the presence of granulomas on histopathology (100%). No other notable associations were observed.

Conclusion. Dermoscopy is a potentially useful tool to aid in the diagnosis and treatment monitoring of leprosy. Limitations of this study include the small sample size, the preponderance of subjects in the lepromatous pole, and assessments by a single trained dermoscopist. A longer study duration including a larger number of newly diagnosed leprosy patients is recommended.