Background: 

Giant Cell Arteritis (GCA), myasthenia gravis (MG), and HIV rarely coexist, with no documented case of this triad in the literature. Overlapping symptoms like jaw claudication, ptosis, and visual disturbance may create significant diagnostic challenges. This represents the first documented coexistence of MG exacerbation, HIV, and clinically diagnosed GCA based on ACR classification criteria. 

Case Presentation: 

An 80-year-old male with HIV (CD4 162 cells/µL) and MG presented with his third exacerbation in six months: left-sided ptosis, right-sided jaw claudication, visual disturbance, and dysphagia. Examination revealed bilateral temporal tenderness and bulky temporal arteries. Labs showed normocytic anemia (Hgb 10.3), ESR uptrending 63→76, CRP 5.6, and weight loss. Temporal ultrasound was negative. The patient met four of five ACR 1990 GCA criteria (age ≥50, temporal tenderness, ESR ≥50, jaw claudication). Pyridostigmine was adjusted to 90 mg TID, and prednisone 80 mg PO daily was initiated to address both MG and GCA, with a planned taper.

Significant improvement followed: ptosis resolved, claudication and tenderness subsided, swallowing improved, ESR declined 76→39, CRP 5.6→0.5, and CD4 improved to 322 during his admission. Biopsy was deferred by vascular surgery for outpatient evaluation due to the risk of myasthenia gravis decompensation and FDG-PET/CT vasculitis protocol will be used as a contingency.

Discussion: 

Jaw claudication may reflect ischemia (GCA) or bulbar weakness (MG). Three relapses in six months prompted vasculitis evaluation. Robust corticosteroid response with inflammatory marker decline supports active GCA. Biopsy sensitivity is limited (40–70%) and further reduced by steroid pretreatment. Steroid-sparing agents offer dual therapeutic benefit for both MG and GCA while limiting immunosuppressive burden in HIV.

Conclusion: 

Recurrent myasthenia gravis exacerbations with systemic inflammatory signs should prompt evaluation for occult comorbidities. Outpatient biopsy and PET remain planned for further characterization.