Trigeminal neuropathy as the first symptom of mixed connective tissue disease: case report and literature review.

This article focuses on a case report and literature review of trigeminal neuropathy as the initial symptom of mixed connective tissue disease (MCTD), a rare autoimmune disorder combining features of systemic lupus erythematosus, scleroderma, and polymyositis. The reported case involved a 48-year-old man presenting with isolated trigeminal sensory neuropathy, confirmed by quantitative sensory testing and elevated anti-U1 ribonucleoprotein (anti-U1-RNP) antibodies, alongside hand swelling and lymphadenopathy, fulfilling the 2019 Japanese diagnostic criteria for MCTD. The report emphasizes the importance of considering MCTD in patients with orofacial sensory disturbances, recommending comprehensive clinical and serologic evaluation to enable early diagnosis and management, given the potential for serious complications such as pulmonary hypertension. The article also reviews previous cases, noting that trigeminal neuropathy in MCTD is typically bilateral and may be refractory to pharmacologic treatment, underscoring the need for multidisciplinary assessment.