PO:30:160 | A rare case of juvenile systemic sclerosis

Marta Arese^1|2, Francesco Baldo³, Stefania Costi³, Achille Marino³, Cecilia Chighizola^1|3, Roberto Felice Caporali^1|2 | ¹Azienda Ospedaliera Universitaria Senese, Università degli Studi di Siena; ²Reumatologia Clinica, ASST Gaetano Pini-CTO, Milano, Italy

Juvenile Systemic Sclerosis (jSSc) is a rare, autoimmune connective tissue disease with onset in the pediatric age; the pathogenesis appears to be mediated by adaptive immunity, with autoantibody production, endothelial dysfunction, proliferative vasculopathy leading to ischemia and tissue fibrosis with variable involvement of the skin and internal organs.^1,2 The average age at diagnosis in the pediatric age is between 8 and 12 years, with a clear female prevalence. Compared to the adult-onset form, pulmonary involvement is more common and severe in juveniles, while renal involvement is less frequent.^3,4

We present the rare case of a 16-year-old female patient with rapidly progressive diffuse cutaneous jSSc. The disease began in 2019 at the age of 11 with Raynaud’s phenomenon leading to digital ulcers. Physical examination revealed puffy hands and cutaneous fibrosis (J4S equal to 12.5/40). Thoracic auscultation showed normal vesicular breath sounds, no crackles. Serological tests showed ANA positivity at a titer of 1:1280 and anti-Scl70 antibodies. Capillaroscopy in 2023 showed a scleroderma pattern; the punch skin biopsy in 2022 showed dermal and hypodermal sclero-hyalinosis (score 2), mild perivascular and periannexal inflammatory infiltrate (score 1), and annexal atrophy (score 1), compatible with scleroderma. Pulmonary Function Tests (PFTs) in 2024 revealed moderate-to-severe restrictive syndrome (FVC 65%, FEV1 68%, DLCO/Va 94%.) and initial signs of fibrosis on 2024 thoracic HRCT (interlobular septal thickening <5%, ground-glass areas, emphysema, bronchiectasis not present on HRCT in 2021). Due to the relapsing nature of the digital ulcers, therapy was started with intravenous prostanoids and bosentan, with good control of the lesions. The patient was treated with rituximab every six months (2019–2023) then suspended due to recurrent infections, then with methotrexate (2019–2020 suspended due to ineffectiveness, resumed in 2023 and suspended in 2024 due to hypertransaminasemia). She is currently on therapy with mycophenolate mofetil (started in 2024, 600 mg/m² twice a day), bosentan 125 mg/day since 2023, prednisone (5 mg/day), nifedipine as needed, gastroprotection, and monthly iloprost during the winter months. Despite the progressive nature of the disease, a reduction in recurrent trophic ulcers, improvement in cutaneous trophism, and a reduced progression of pulmonary fibrosis were noted, with improvement in semiannual Pulmonary Function Tests (2023 DLCO/Va 64%, FVC 56% - 2024 DLCO/Va 104%, FVC 65%).

jSSc is a rare and complex disease. The scarcity of specific data in the pediatric population makes greater clinical characterization urgent to define targeted therapeutic strategies.