Novel In-Office Injectables for the Dermatology–Rheumatology Patient: Botulinum Toxin, Sodium Thiosulfate, and Hyaluronidase

Patients with systemic sclerosis (SSc) and related systemic autoimmune rheumatic diseases experience cutaneous complications that systemic immunosuppression and vasodilators frequently fail to control. These include refractory Raynaud phenomenon with digital ischemia, calcinosis cutis, and perioral fibrosis with microstomia. Three physician-administered injectable therapies can be readily incorporated in a routine dermatology office at modest cost using widely available equipment: botulinum toxin A (BoNT-A) for digital ischemia, sodium thiosulfate (STS) for calcinosis cutis, and hyaluronidase for microstomia. All three treatments are used off-label, and are supported primarily by observational evidence. This review summarizes the mechanistic rationale, current evidence, injection technique, dosing, and safety of each agent, supplemented by practical observations derived from five years of clinical experience.