Guillain-Barre Syndrome Unmasking Asymptomatic Peripheral Spondyloarthritis

Guillain-Barre syndrome (GBS) is an immune-mediated disease characterized by evolving ascending limb weakness, sensory loss, and areflexia. While moderate and severe back or extremity pain is frequent in patients with GBS due to polyradiculopathy, the literature does not reveal any association of acute demyelinating disorders and asymptomatic sacroiliitis, which becomes symptomatic during the episode of the demyelinating illness. We present the case of a young male patient with acute-onset quadriparesis diagnosed as GBS based on clinical evidence and electrophysiological criteria, who developed acute low backache 7 days after the onset of acute demyelinating illness. Subsequently, a diagnosis of peripheral spondyloarthritis (SpA) was confirmed based on clinical outline (past history of bilateral heel pain and acute low backache), along with magnetic resonance imaging (MRI) and computed tomography findings of focal erosions with surrounding sclerosis on iliac para-articular surface bilaterally. The patient responded well to the therapy (intravenous immunoglobulin, hydroxychloroquine, and symptomatic treatment) thereafter. It is crucial to consider the possibility of SpA when patients with GBS complain of low backache. Timely diagnosis will not only aid in the institution of early therapy but also prevent any long-term sequelae. MRI can visualize active inflammation at sacroiliac joints and spine in recent-onset disease.