Correlation of Dermoscopic and Histopathologic Patterns in Leprosy - A Pilot Study

Background: Leprosy is a chronic granulomatous disease caused by Mycobacterium leprae. It is diagnosed based on clinical features and confirmed on the histological findings and peripheral slit-skin smear staining. Dermoscopy is a handy, easily accessible tool to diagnose this granulomatous disease and classify patients based on the immunological and clinical response. Methods: A single spot observational analysis was conducted in a tertiary hospital in North India. Patients attending the leprosy clinic and admitted patients for institutional therapy on the day of the study were enrolled in the cohort. The clinical and histological findings were correlated with the characteristic dermoscopy findings. A total of 50 patients were included in the study. All patents included in the study were on multidrug therapy and anti-lepra reaction drugs for a duration of less than 6 months. Results: The dermoscopy findings correlated with the clinical and histological findings. Tuberculoid poles of leprosy classically showed loss of hair and skin pigment along with absence of white dots as sweat glands in dermoscopy. Lack of blood vessel changes ruled out any lepra reaction. Lepromatous pole of leprosy on the other hand showed characteristic xerosis and white scaling on dermoscopy in the background of hypotrichosis and hypopigmentation. Leprosy reactions were characterized by blood vessel changes and arborizing blood vessels were characteristic in erythema nodosum leprosum, and a diffuse erythema was a clue toward diagnosing type I lepra reaction. Interestingly, clofazimine-induced pigmentation was picked up characteristically on dermoscopy as a "honey comb pattern". Conclusion: Dermoscopy is certainly a handy tool in aiding the diagnosis of leprosy, lepra reactions, and course of therapy. Characteristic patterns during the course of leprosy would certainly facilitate a quick and definitive diagnosis of patients suffering from leprosy. Also, patient drug compliance particularly to clofazimine can also be picked up objectively on dermoscopy.