Topical sodium thiosulfate for calcinosis cutis associated with autoimmune connective tissue diseases: the Mayo Clinic experience, 2012–2017

Summary In this case series, we retrospectively identified all patients treated with topical sodium thiosulfate ( TST ) for calcinosis cutis ( CC ) associated with underlying autoimmune connective tissue diseases at Mayo Clinic (Rochester, MN , USA ) during the period 1 January 2012 to 27 June 2017. Of 28 patients identified (mean age 57.0 years; 96% female), 19 (68%) had clinical improvement of their CC with TST , 7 (25%) had no response and 2 (7%) had unknown response. There were adverse events in three patients: two had skin irritation and the third, who had a zinc allergy, experienced pain with application. Overall, our findings support those of previous case reports that TST appears to be a relatively well‐tolerated adjuvant treatment for CC , although future studies with a control group are warranted to assess the true efficacy of TST for the indication of CC .