Thank you to Vaibhav for making an appearance while on the lung consult service to present a diagnostic mystery! He presented the case of a middle aged man presenting with 4-6 weeks of HA, night sweats and cough who was found to have severe eosinophilia > 5,000!! We never did identify the cause of this patient’s elevated eos, however given recent travel he was treated with albendazole despite negative serology tests for parasitic infections. While on therapy and without steroids his eosinophilia gradually improved.
- The differential diagnosis for eosinophilia can be remembered with the pneumonic NAACP – Neoplasm, Addison’s disease, Allergy (includes medications), Collagen Vascular disease (GPA) and Parasitic infections (thanks Greg!!).
- The most common cause of eosinophilia worldwide is helminthic infections and most common cause in industrialized nations is atopic disease.
- The differential diagnosis narrows when one considers severe >(5,000k) eosinophilia:
- Primary hematologic disease (eosinophilic leukemia, systemic mastocytosis with eosinophilia)
- Paraneoplastic (Lymphoma)
- Infectious – thank you Jen for this ddx: lymphatic filiariasis, toxocara, trichinosis and strongyloides all cause eos > 5,000
- NOTE: giardia, malaria and babesia do NOT produce eosinophilia.
- Tissue damage is more likely at eosinophil counts >1500, but can also occur at lower levels!
For those who want to learn more about Eosinophilia!!
- Eosinophilia: Absolute eosinophil count > 500
- Hypereosinophilia: Severe eosinophilia >1500
- Hypereosinophilic syndrome (HES): Hypereosinophilia (1,500) lasting > than 6 months on at least 2 occasions with end-organ dysfunction due to eosinophilia.
- Recommended workup for unexplained eosinophilia:
– CBC, diff, blood smear
– Chem, u/a, LFTs
– Troponin (cardiac infiltration)
– Strongyloides serology (stool as we discussed not as helpful if patient is without diarrhea)
– Vit B12 (elevated in myeloproliferative neoplasm)
– Flow cytometry for lymphocyte subsets
– Chest Xray
– Serum tryptase (mastocytosis or hypereosinophilic syndrome)
Can also send if appropriate:
– Molecular testing for hematologic disorders
– Immunoglobulin levels (autoimmune disease or immunodeficiency)
– Morning cortisol
– Stool O&P
– Viral serologies (e.g. HIV, HTLV)
– Serologies for specific parasitic infections (e.g. schistosomiasis)
– CT, lymph node biopsy
iii. Specific organ involvement:
- Well’s syndrome (eos cellulitis),
- Shulman’s syndrome (eos fasciitis)
- Eosinophilic panniculitis
- Kimura’s disease- amgiolymphoid hyperplasia
- Pulmonary- interstitial lung disease, hypersensitivity pneumonitis,
- Loeffler’s (pulm infiltrates w/eos due to helminthic infxn)
- Eosinophilic gastroenteritis
- Cardiac- hypersensitivity myocarditis, endomyocardial fibrosis
See this article for much more on Evaluation and ddx of marked, persistent eosinophilia!