A Case of Systematized Epidermal Nevus (Nevus Unius Lateris) in a 20-year-old Filipino Female Treated with Ablative CO2 Laser and Topical Tretinoin.

This is a case of a 20-year-old female with no known comorbidities presenting with verrucous plaques arranged in a unilateral blaschkoid distribution at birth. Biopsy was consistent with epidermal nevus hence patient was diagnosed as systematized epidermal nevus, Nevus Unius Lateris type. Gold standard treatment is full thickness surgical excision however, due to the extensive involvement, treatment of this condition remains a challenge. Hence, non-surgical combination of ablative CO₂ laser and topical tretinoin 0.1% were done. Thinner lesions (1-3 mm) showed lower recurrence (50%) as compared to thicker lesions (>3 mm) showing 100% recurrence after six months. Hence, another CO₂ laser session is needed. Quality of life was measured using the Dermatologic Life Quality Index (DLQI) with noted 35% improvement post-treatment.