Successful Treatment of Localized Eruptive Pruritic Papular Porokeratosis with A Single Session of Cryotherapy: A Case Report.

Eruptive pruritic papular porokeratosis (EPPP) is a rare subtype of porokeratosis characterized by acute-onset pruritic papules, and conventional therapies often yield unsatisfactory results. While cryotherapy has been proposed as a potential intervention, successful cases with long-term follow-up remain sparse. We report a 58-year-old male with EPPP confined to the thighs for 2 years, refractory to oral antihistamines and topical glucocorticoids. The patient received a single session of liquid nitrogen spray cryotherapy (spray distance 2 cm, 10-15 seconds per lesion, one freeze-thaw cycle) and was followed up for 3 years. Complete lesion regression and pruritus resolution were achieved 2 weeks post-treatment, with no recurrence observed. The only adverse events were mild persistent hyperpigmentation and superficial atrophic scars, which did not affect cosmetic outcomes. To the best of our knowledge, this is the first reported case of EPPP successfully managed with single-session cryotherapy. This case supplements clinical evidence for cryotherapy in EPPP, offering an effective, safe, and economical alternative for patients with limited resources, poor adherence, or contraindications to systemic therapy.