Pityriasis lichenoides chronica in a Mexican pediatric series: clinical-epidemiological profile and therapeutic approach.

BACKGROUND: Pityriasis lichenoides chronica (PLC) is a rare dermatosis in children, with limited epidemiological data restricting its clinical and therapeutic characterization. METHODS: A retrospective case series was conducted at two tertiary care hospitals in Mexico City. Electronic records of patients younger than 18 years of both sexes with a diagnosis of PLC confirmed by histopathology were included in the study. The study period was from January 2017 to March 2025. RESULTS: Thirty-five confirmed cases were analysed (51.4% female and 48.6% male). The mean time to diagnosis was 2.4 years after lesion onset. The median disease duration was 24 months (interquartile ranges 9-49), with recurrence in 67.5% of cases. The most common sites were the trunk and extremities (65.7%), with predominance of erythematous-squamous papules and plaques (48.6%) that, upon resolution, left hypopigmented macules in 80% of patients. Phototherapy was used in 25.7% and oral methotrexate (MTX) in 22.9% of cases. In patients with prolonged disease duration (> 36 months), higher recurrence rates, longer MTX use, and, in some cases, greater use of phototherapy were observed. CONCLUSIONS: Pediatric PLC in a Mexican case series showed a chronic and recurrent course, with a low rate of resolution. The high frequency of recurrences and therapeutic variability, including MTX and phototherapy in prolonged cases, highlights the need for standardized treatment protocols.