Skinternal Medicine Case 7: Evaluation of Calcinosis and Tight Skin in Systemic Sclerosis

The case discussed involves a patient in her 70s referred for evaluation of tight skin and calcinosis associated with systemic sclerosis. Her symptoms began in her 20s and progressed to include joint pain and limited mobility. Importantly, she did not manifest key symptoms typical of systemic sclerosis, such as sclerodactyly, Raynaud's phenomenon, or specific antibody positivity. Instead, her skin remained mobile, which is contrary to the features of systemic sclerosis. Upon examination and imaging, significant joint destruction suggested psoriasis and ankylosing spondylitis rather than systemic sclerosis. A large punch biopsy indicated a non-sclerotic pathology with abnormal deposition of calcium, raising the suspicion of familial tumoral calcinosis. This condition, characterized by large calcified masses and hyperphosphatemia, was confirmed through laboratory findings showing elevated FGF23 levels. The management plan included dietary phosphate restriction, phosphate binders, and medications targeting interleukin-1 to control inflammation and pain. Ultimately, the patient's ongoing management was optimized after consultation with the NIH, resulting in improved symptoms and normalization of inflammatory markers, emphasizing the importance of considering alternative diagnoses in cases of atypical calcinosis.