BI20 Treatment of refractory warts in idiopathic CD4 lymphopenia with pulsed-dye laser therapy

Abstract We present a case of recalcitrant viral warts in a patient with idiopathic CD4 lymphopenia, successfully treated with pulsed-dye laser (PDL) therapy. A 59-year-old man was referred to the infectious diseases service with a 10-year history of cutaneous warts affecting his left foot and both hands. He had previously tried topical salicylic acid, cryotherapy, silver nitrate therapy, curettage and cautery, electrocautery and SWIFT microwave therapy, none of which had proved successful. There was a past medical history of treated hypertension and hiatus hernia. There was no history of genital warts. On examination, both common and plantar warts were observed on the feet, and plantar warts on the hands. Further investigations revealed CD4 lymphopenia (0.12–0.18 × 109 CD4 cells L−1). Tests for HIV and human T-lymphotropic virus 1 were negative, and immunoglobulin levels were normal. Computed tomography imaging did not reveal lymphadenopathy or evidence of sarcoidosis, and bone marrow examination was declined. Whole-genome sequencing did not identify a known genetic aetiology, which is consistent with idiopathic CD4 lymphopenia. A course of unlicensed therapeutic human papillomavirus vaccination and topical imiquimod for 6 months was attempted, without benefit. He was referred for carbon dioxide laser ablation of the warts, which removed the majority of the crusts; however, recurrence was noted within 4 months. A decision was therefore made to attempt PDL therapy, which had not previously been performed for this indication in our trust. The patient underwent 3-weekly treatments with 595-nm PDL, with triple-stacked pulses to treated areas, for 10 months, with an excellent response. The warts on both hands were effectively cleared; the warts on the feet were therefore treated in the same fashion, again with an excellent response, with sustained resolution. On review of the literature, we identified a number of retrospective studies reporting the use of PDL for viral warts, with favourable results and good tolerance; a recent study demonstrated that 95% of 203 patients with multiple viral warts treated with PDL achieved excellent clearance. However, there is a lack of randomized trials evaluating the efficacy of this treatment, and few studies focus on its use in immunocompromised people. PDL remains unlicensed in the UK for treatment of warts and is not widely available. We report this case with the objective of highlighting (i) the potential value of this treatment for refractory warts in immunocompromised individuals and (ii) the need for clinical trials to assess its efficacy in immunocompromised cohorts.