A young man w/ history of asthma and sinusitis presents with myalgias, intermittent fevers, and purpuric rash on palms/soles after traveling in South America for months. Initial labs showed a striking eosinophilia of over 70%. During his course, he developed abdominal pain and mononeuritis multiplex. He initially underwent an extensive infectious workup, but was ultimately diagnosed with EGPA (Churg Strauss) and improved slowly with immunosuppresion.
A few points that came up:
1) Mnemonic for eosinophilia – NAACP
Neoplasm (HL, carcinomas, leukemia/lymphoma; also consider hypereosinophilic syndrome)
Asthma / Allergy
Connective tissue disease (EGPA, SLE, RA, myositis)
Parasites (Strongyloides, ascaris, schistosoma, lice, scabies)
2) How does one distinguish between EGPA and Hypereosinophilic Syndrome?
Hypereosinophilic Syndrome just describes end-organ dysfunction due to eosinophils. It can be the primary process OR secondary to another process (such as parasitic infection). When the diagnosis of EGPA is made, usually patients are NOT said to have “hypereosinophilic syndrome”, as it is unclear what damage is due to the eosinophils versus the vasculitis itself.
3) Teaching points on EGPA
*ANCA is only 40% sensitive (this is unlike MPA or GPA, where it is quite sensitive)! The EGPA manifestations may differ in ANCA-negative (heart involvment, fever) versus ANCA-positive (vasculitis, renal, neuropathy) but these patterns are not always seen
*Our patient illustrated the typical phases of disease:
–Prodromal – atopic disease, allergic rhinitis, asthma
-Eosinophilic phase – peripheral eosinophilia, organ infiltration including lung and GI
-Vasculitic phase – life-threatening systemic small and medium-vessel vasculitis w/ constitutional sx