A Diagnostic Algorithm for Eosinophilic Granulomatosis with Polyangiitis Initially Diagnosed as Lumbar Disc Hernia or Lumbar Spinal Stenosis: Personal Experience and Review of the Literature.

Eosinophilic granulomatosis with polyangiitis (EGPA, Churg-Strauss syndrome) is a rare systemic vasculitis and is difficult to diagnose. EGPA has a number of symptoms including peripheral dysesthesia caused by mononeuropathy multiplex, which is similar to radiculopathy due to lumbar disc hernia or lumbar spinal stenosis. Therefore, EGPA patients with mononeuropathy multiplex often visit orthopedic clinics, but orthopedic doctors and spine neurosurgeons have limited experience in diagnosing EGPA because of its rarity. We report a consecutive series of patients who were initially diagnosed as having lumbar disc hernia or lumbar spinal stenosis by at least 2 medical institutions from March 2006 to April 2013 but whose final diagnosis was EGPA. All patients had past histories of asthma or eosinophilic pneumonia, and four out of five had peripheral edema. Laboratory data showed abnormally increased eosinophil counts, and nerve conduction studies of all patients revealed axonal damage patterns. All patients recovered from paralysis to a functional level after high-dose steroid treatment. We shortened the duration of diagnosis from 49 days to one day by adopting a diagnostic algorithm after experiencing the first case.