Isolated scleroderma of the lower extremities misdiagnosed as lymphedema and presenting with scleroderma renal crisis

Systemic sclerosis (SSc) is a chronic autoimmune disorder characterized by progressive fibrosis, vasculopathy, and immune dysregulation. The disease commonly presents with Raynaud's phenomenon and skin thickening, commonly of the upper limb. Isolated lower extremity presentation is uncommon and often misdiagnosed. This diagnostic uncertainty may lead to delayed recognition and increased morbidity, particularly when SSc mimics lymphedema in the early stages. We report a case of a 61-year-old female who initially presented with lower extremity swelling and was misdiagnosed with primary lymphedema. Despite treatment with diuretics and compression therapy, her symptoms progressed to involve her upper extremities, prompting further evaluation. Physical examination revealed non-pitting lower extremity scleroderma, sclerodactyly, puffy hands, and nailfold capillary abnormalities. Laboratory workup was positive for anti-RNA polymerase III antibodies, a marker associated with an increased risk of scleroderma renal crisis. The patient developed scleroderma renal crisis after a delayed diagnosis, necessitating hospital admission and initiation of angiotensin-converting enzyme inhibitors. This case highlights the challenges in distinguishing early lower extremity SSc from lymphedema. Early identification of atypical SSc presentations is critical to be cognizant of life-threatening complications such as scleroderma renal crisis. Clinicians should maintain a high index of suspicion for SSc in patients with persistent non-pitting lower extremity swelling, skin thickening, and abnormal capillaroscopy findings, even in the absence of initial upper limb involvement.