Worsening of calcinosis cutis with teriparatide treatment in two osteoporotic patients

Summary We present two cases of patients with systemic autoimmune diseases (one with dermatomyositis and one with CREST syndrome) who presented with a worsening of calcinosis cutis after treatment of osteoporosis with teriparatide. To our knowledge, this association is not described in the literature and might be considered in the spectrum of adverse reactions to teriparatide. What's already known about this topic? After searching the literature with the medical subject heading terms ‘calcinosis cutis’, ‘teriparatide’ and ‘complications’, we found no known literature on this topic. What does this study add? We report two cases of systemic autoimmune disease with concomitant calcinosis cutis that worsened on treatment with teriparatide. We alert practitioners to the possible side‐effects of teriparatide in patients with dermatomyositis and CREST syndrome who have calcinosis cutis.