# Annular Lichen Planus of the Penis Successfully Treated with Topical Tacrolimus 0.1% Ointment: A Case Report and Systematic Review of the Literature

## TL;DR

A rare case of annular lichen planus on the penis was successfully treated with tacrolimus ointment, showing no recurrence after a year.

## Contribution

This case report presents a successful alternative treatment for penile ALP using topical tacrolimus.

## Key findings

- A 63-year-old male with penile ALP achieved complete resolution with topical tacrolimus 0.1% ointment.
- No recurrence was observed after one year of follow-up.
- Literature review shows limited prior reports of penile ALP cases.

## Abstract

Introduction: Annular Lichen Planus (ALP) of the penis is a rare variant of genital lichen planus. Clinically, it is characterized by violaceous plaques with an annular configuration and central clearing. The diagnosis can be challenging, especially considering its rarity, and histopathological confirmation is often necessary to differentiate it from other annular dermatoses. Methods: We report a rare case of genital ALP in a male patient, while reviewing previously reported cases to provide a comprehensive overview of this rare condition. Results: A 63-year-old white male was referred to our outpatient department presenting with symptomatic annular erythematous-violaceous lesions on the glans penis. A diagnosis of genital ALP was clinically suspected and subsequently confirmed by histopathology. The patient was started on topical tacrolimus 0.1% ointment twice daily, achieving a complete clinical resolution after 6 consecutive weeks of treatment. No signs of local recurrence were observed after a one-year follow-up. We carried out a systematic review of the literature which identified a limited number of similar cases. Conclusions: This review underscores the importance of clinical suspicion and biopsy for accurate diagnosis and effective management of penile ALP. Topical tacrolimus 0.1% ointment is a safe and effective treatment for penile ALP and can be used as an alternative of corticosteroids.