A Case of Rapidly Progressive Unilateral Non-Nephrogenic Hemorrhagic Bullous Calciphylaxis Responding to Systemic Sodium Thiosulfate Therapy

Background. Calciphylaxis is a rare and life-threatening condition characterized by cutaneous necrosis resulting from vessel calcification and thrombosis. Commonly associated with end-stage renal disease and hyperparathyroidism, calciphylaxis presents as retiform purpura evolving into necrotic eschars. Case Report. This report details an atypical case of non-nephrogenic unilateral bullous calciphylaxis in a 71-year-old female, emphasizing the importance of considering calciphylaxis in the differential diagnosis of bullous disorders. The patient’s presentation included hemorrhagic bullae on the left leg, prompting a challenging differential diagnosis. Diagnosis was confirmed by skin biopsy, highlighting the role of confirmatory biopsy in atypical cases such as this, with a broad differential diagnosis. Treatment involved intravenous sodium thiosulfate infusions and wound care, resulting in significant improvement after 6 months. Conclusion. This case underscores the diagnostic complexity of bullous calciphylaxis, and clinicians are urged to consider this condition in patients with painful bullae and retiform purpura. Early recognition is crucial for initiating prompt intervention and improving outcomes in patients with this high-mortality disease.