Effectiveness of sodium thiosulfate in acquired reactive perforating collagenosis: A case report

RATIONALE: Acquired reactive perforating collagenosis (ARPC) is a challenging dermatological complication in end-stage renal disease (ESRD) patients on hemodialysis, characterized by transepidermal elimination of degenerated collagen and intense pruritus. Treatment options are limited and lack consensus. Based on its established safety profile in ESRD and pathophysiological rationale, we evaluated sodium thiosulfate (STS) as a novel therapeutic option for ARPC. PATIENT CONCERNS: A 70-year-old male with ESRD on hemodialysis and type 2 diabetes presented with widespread pruritic papules consistent with ARPC. DIAGNOSES: The diagnosis of ARPC was confirmed histologically by Masson trichrome staining. INTERVENTIONS: After unsatisfactory responses to topical steroids and antihistamines, intravenous STS (3.2 g after hemodialysis, 3 times weekly) was initiated. OUTCOMES: The patient showed marked clinical improvement in pruritus and skin lesions within 1 month, with a corresponding decrease in eosinophil count and IgE levels. No adverse effects, such as metabolic acidosis or gastrointestinal symptoms, were observed. LESSONS: STS may be an effective and well-tolerated treatment for ARPC in hemodialysis patients. The observed immunomodulatory changes, though possibly related to symptom resolution, support further investigation into its mechanism of action.