Porokeratosis ptychotropica and concurrent condyloma acuminata respond well to photodynamic therapy

Porokeratosis ptychotropica (PPt), a rare variant of porokeratosis, occurs predominantly in the gluteal cleft, buttocks, perineum, and genitals. Here we present the case of a 73-year-old man with patchy hyperkeratotic lesions and verrucous growths over his buttocks, perianal area, gluteal cleft, and scrotum, which result in an uncomfortable moist sensation over his anus. Skin biopsies of all lesions revealed a combination of cornoid lamellae, koilocytes, and P16 focal-positive immunohistochemistry, indicating condyloma acuminata overlying the PPt. A standardized and effective treatment regimen for porokeratoses is currently lacking. PDT treats a variety of conditions by inducing oxidative stress and enhancing local immunity, and offers a benefit for perianal lesions due to its preservation of anal sphincter function. Three monthly topical photodynamic therapy (PDT) sessions with 78 mg/g 5-aminolevulinic acid (5-ALA) gel and 635 nm red light (total 78 J/cm²) were performed over the patient's perianal and buttock region, and two monthly PDT sessions were performed over his scrotum. 405 nm blue light was used to visualize 5-ALA bioutilization via protoporphyrin IX fluorescence before each session. At 2-month follow-up, the patient reported significant clinical and symptoms improvement, and remains symptom-free at 6-months follow-up. This represents the first report of concurrent PPt and CA. We hope to demonstrate the versatility of PDT and expand its list of indications, and demonstrate that, while PPt and concurrent CA is challenging to treat, PDT may offer an alternative therapeutic option.