Photodermatol Photoimmunol Photomed. 2026 Mar;42(2):e70081. doi: 10.1111/phpp.70081.
ABSTRACT
BACKGROUND & PURPOSE: Bath or oral PUVA is a key treatment modality for palmoplantar pustulosis (PPP), whereas topical PUVA and UVB have proven ineffective. Immersion in water prior to UVA may represent a therapeutic option.
METHOD: This study was a prospective, open label, three-arm parallel-group randomized controlled trial conducted from 2014 to 2017. The study was conducted in Ankara University Medical School Department of Dermatology and Venereology. The ethical committee approval was granted (07.10.2013- no 15-585-13) and the trial registration number was NCT06458868. All participants had a biopsy with a confirmed diagnosis of PPP. The primary endpoint of the study was defined as having achieved a PPASI50 response at week 36. Out of 114 eligible patients, 68 patients were enrolled in the study. Randomization was performed using a computer program (clinstat). All arms received UVA irradiation for 36 sessions starting at 0.25 J/cm2 with incremental increases. Bath PUVA arm: Local baths with water containing 0.5 mg methoxypsoralen per litre at 37°C for 20 min prior to phototherapy. Tap Water (TW) Group received local baths in tap water, Saltwater (SW) Group received local baths in 25% w/v saline solution, both at 37°C for 20 min prior to phototherapy.
RESULTS: Out of 68 enrolled participants, 50 completed the study (F/M: 43/7, age: 47.8 ± 10.3 years). In the intention to treat set, PPASI-50 response rates were 38.5%, 57.1%, and 71.4% in the TW, SW, and bath-PUVA groups (p = 0.085). In the per protocol set, corresponding rates were 52.6%, 85.7%, and 88.2% (p = 0.031).
CONCLUSIONS: Immersion in water or saltwater prior to UVA without psoralens may provide a therapeutic effect.
PMID:41712670 | DOI:10.1111/phpp.70081
