Successful tocilizumab-based combination therapy for a case of rapidly progressive adult deep morphea with multiple antiphospholipid antibodies: a case report and literature review.

Background: Localized Scleroderma (LoS), particularly aggressive subtypes such as Deep Morphea (morphea profunda), is a rare chronic autoimmune fibrosing disorder that can extend into the subcutaneous tissue, fascia, and muscle. These deep forms carry a high risk of functional impairment. Tocilizumab (TCZ), an anti-interleukin-6 (IL-6) receptor antibody, has emerged as a promising therapy for severe, refractory cases. However, its reported use typically follows the failure of standard immunosuppressive agents like methotrexate (MTX). Case presentation: We report the case of a 19-year-old male with a rapidly progressive deep morphea of the left lower extremity, with only a two-month history from onset. Initial symptoms included skin hardening, hyperpigmentation, and mild restriction of foot motion. Skin biopsy confirmed deep morphea, showing lymphoplasmacytic inflammation and eosinophilic fibrosis extending into the subcutaneous septa and muscle interstitium. Pre-treatment magnetic resonance imaging (MRI) revealed prominent edema (high T2 signal) in the subcutaneous fat and blurred muscle fascial planes, consistent with active deep inflammation. Uniquely, the patient was seropositive for multiple antiphospholipid antibodies (aPLs), including Lupus Anticoagulant (dRVVT ratio 1.34), anti-phosphatidylserine/prothrombin IgM (143.72 U), β2-glycoprotein I IgM (30.9 CU), and anticardiolipin IgM (28.2 CU). Given the rapid progression and deep tissue involvement, an early intensified combination regimen of TCZ (640 mg IV every 4 weeks), MTX (12.5 mg weekly), high-dose corticosteroids (IV pulses followed by 30 mg/day oral prednisone taper), and prophylactic aspirin (100 mg daily) was initiated. Follow-up MRI at six months showed a marked reduction in the deep tissue edema, correlating with significant clinical improvement in skin induration and tightening by nine months post-treatment. No serious adverse events were observed during follow-up. Conclusion: This case demonstrates the successful outcome of early TCZ-based combination therapy in rapidly controlling the aggressive inflammatory process of an adult deep morphea. The objective radiological response validates this early intervention strategy, which deviates from the typical second-line use of TCZ. Furthermore, the case highlights a rare but clinically important overlap between severe localized scleroderma and multiple aPL seropositivity.