1. Terminology

    1. Eosinophilia is defined as an absolute count >500

    2. Mild 500-1500, Moderate 1500-5000, Severe >5000

    3. Hypereosinophilia is >1500 with or without end organ damage

    4. Hypereosinophilic syndrome is a count >1500, on 2 separate occasions, PLUS organ dysfunction

  2. Etiology, think CHINA

    1. C – Collagen vascular disease (EGPA)

    2. H – Helminthic (parasites, Strongyloides)

    3. I – Idiopathic hypereosinophilic syndrome

    4. N – Neoplasia (lymphomas most common)

    5. A – Allergy, atopy, asthma, drug induced (carbamazepine, sulfonamides)

  3. Think Neoplastic disease!

    1. For severe eosinophilia, need to rule out neoplasm including

      1. Primary hypereosinophilic syndrome

      2. Acute or chronic eosinophilic leukemia

      3. B-cell or T-cell leukemia / lymphoma

    2. Sezary syndrome

      1. Type of cutaneous T cell lymphoma (CTCL)

      2. Presents with erythroderma (erythema covering at least 80% of body surface area), lymphadenopathy, and pruiritic skin

      3. Can see increased serum IgE, eosinophilia, and Sezary cells – mononuclear cells with grooved cerebriform nuclei seen on peripheral smear