CSC Sep-02
Eosinophilia Everywhere
Key Points:
• Eosinophilia is most often caused by helminthic infections, allergic reactions, or hematologic/neoplastic
disorders
• The hypereosinophilic syndrome is defined as otherwise unexplained eosinophilia of > 6 months duration
with evidence of end-organ dysfunction
• Loffler’s syndrome is transient pulmonary infiltrates associated with eosinophilia; Loffler’s endocarditis
causes a restrictive cardiomyopathy caused by endomyocardial fibrosis and associated with peripheral
eosinophilia
1. What is the differential diagnosis of eosinophilia?
• Allergic: allergic rhinitis, asthma, medication-related
• Infectious:
-- Parasitic: mainly helminthic infections (Strongyloides, hookworm, Toxocara)
-- Fungal: aspergillus, coccidiodiomycoses
-- HIV: usually not just caused by HIV but related to relative lymphopenia, medication reaction,
adrenal insufficiency, or eosinophilic folliculitis
• Hematologic/Neoplastic: hypereosinophilic syndrome (see below), systemic mastocytosis,
eosinophilic leukemia, lymphoma
• Collagen-Vascular: Churg-Strauss is fairly unusual among the vasculitides for causing eosinophilia
• Miscellaneous: adrenal insufficiency, atheroemboli, congenital immunodeficiencies
2. What is the hypereosinophilic syndrome?
• Definition: blood eosinophilia > 1500/µl for > 6 months
exclusion of other causes of eosinophilia
signs and symptoms of endorgan dysfunction
• Male: female = 9:1; most commonly occurs in 4th decade
• Symptoms include fatigue, cough, SOB, myalgias, angioedema, rash, and fever; however,
manifestations of the disease can range from nearly asymptomatic and subacute to fulminant
• Organ systems involved include cardiovascular (see below under Loffler’s endocarditis --
endomyocarditis progressing to a fibrotic, restrictive cardiomyopathy), CNS (thromboemboli,
encephalopathy, peripheral neuropathy), skin (angioedema, urticaria, nonspecific nodules or papules),
pulmonary (frequently with a negative CXR)
• Ma