Systemic Sclerosis in a Preschool-Aged Patient: An Unusually Early Presentation of an Autoimmune Disease

Introduction: Systemic sclerosis (SSc) is a rare autoimmune disease characterized by skin fibrosis, vascular alterations, and specific autoantibodies. Onset during childhood is uncommon, and presentation at preschool age is exceptional. Case report: We describe an 8-year-old female presenting with a progressive indurated plaque on the left leg, refractory to topical treatments. Laboratory tests revealed positive antinuclear antibodies (ANA) and anti-topoisomerase I (Scl-70). Skin biopsy demonstrated epidermal atrophy and dermal sclerosis consistent with scleroderma. Nailfold capillaroscopy showed a scleroderma pattern, while chest CT, pulmonary function tests, and echocardiography revealed no visceral involvement. A diagnosis of juvenile systemic sclerosis was established. Methotrexate therapy was initiated, along with multidisciplinary follow-up, leading to clinical stabilization at six months. Discussion: Pediatric SSc accounts for less than 5% of all cases, with localized morphea being the most common subtype. Systemic disease at preschool age is exceedingly rare and poses diagnostic challenges. Capillaroscopy and systemic screening are essential for assessing progression risk. Methotrexate is considered first-line therapy in children, although long-term follow-up is mandatory to detect cardiopulmonary complications. Conclusions: This case contributes to the international literature by documenting an unusual presentation of SSc in preschool age, highlighting the importance of early diagnosis, immunomodulatory therapy, and multidisciplinary management.