Tissue calcinosis in dermatomyositis - potential role of combination therapy with JAK inhibitors. Case report and literature review.

Calcinosis is a disabling and difficult-to-treat complication of adult dermatomyositis (DM), juvenile dermatomyositis (JDM), and systemic sclerosis (SSc), for which no standardized therapy is currently available. Growing evidence implicating JAK/STAT signaling in dermatomyositis has prompted interest in Janus kinase inhibitors (JAKi) as a therapeutic option. We describe a 52-year-old woman with long-standing juvenile-onset dermatomyositis and extensive, treatment-refractory calcinosis who received off-label baricitinib after multiple previous therapies. After one month, the patient reported improved general well-being and no new skin ulcerations. During the four-month treatment course, pre-existing microcytic anemia worsened and required blood transfusion, prompting discontinuation of baricitinib because a treatment-related contribution could not be excluded. This case provides a hypothesis-generating observation of possible early symptomatic benefit during JAK inhibition while highlighting the uncertainty regarding efficacy and safety. Prospective studies using standardized clinical, functional, imaging, and safety outcomes are required.