Eosinophilia-Myalgia Syndrome

Epidemiology

  • Epidemic occurred in late 1980’s (1500 cases reported)

Etiology

  • Ingestion of contaminated L-tryptophan

Physiology

  • Pulmonary vasculitis

Pathologic Patterns

  • Vasculitis with fibrointimal hyperplasia: often associated with interstitial infiltrates

Diagnosis

  • PFT’s: decreased DLCO/ increased Vd/Vt ratio
  • ABG: elevated A-a gradient
  • CBC: marked peripheral eosinophilia
  • CXR
    • Alveolar infiltrates:
    • Interstitial infiltrates:
    • Pleural effusion:
  • OLB: diffuse non-necrotizing vasculitis with fibrointimal hyperplasia, interstitial infiltration

Clinical

Typical Eosinophilia-Mylagia Presentation

(>50% of cases had respiratory complaints)

  • Skin Involvement
    • Rash
  • Pulmonary Involvement (50%):
    • Dyspnea
    • Pulmonary Infiltrates (see [[Drug-Induced Pulmonary Eosinophilia]])
    • Interstitial Lung Disease
    • Pulmonary Hypertension (see Pulmonary Hypertension, [[Pulmonary Hypertension]]): due to pulmonary vasculitis
  • Neurologic:
    • Peripheral Neuropathy
    • Myositis
  • Consitutional
    • Myalgias
    • Athralgias
    • Fasciitis
    • Edema
    • Fatigue

Scleroderma-Like Syndrome (see [[Scleroderma]])

  • Has been reported with L-tryptophan ingestion

Treatment

  • Discontinue L-tryptophan
  • Corticosteroids: may be useful
  • Some patients improved, but response is often incomplete (with chronic, progressive disease(

Prognosis

  • May occasionally be chronic, progressive (even with treatment)

References

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