Differential Diagnosis of Eosinophilia
Eosinophilia refers to a condition where the eosinophil count in the blood is elevated above normal levels. This can be due to a variety of causes, ranging from benign to life-threatening conditions. The differential diagnosis can be categorized as follows:
- Single Most Likely Diagnosis
- Parasitic infections: Many parasitic infections, such as hookworm, roundworm, and tapeworm infections, are common causes of eosinophilia. The body's immune response to these parasites often involves an increase in eosinophil production.
- Other Likely Diagnoses
- Asthma and allergic diseases: Conditions like asthma, atopic dermatitis, and allergic rhinitis can cause eosinophilia due to the body's allergic response.
- Drug reactions: Certain medications can induce eosinophilia as part of a drug reaction.
- Skin diseases: Dermatological conditions such as eczema and psoriasis can also lead to elevated eosinophil counts.
- Do Not Miss Diagnoses
- Hypereosinophilic syndrome (HES): A group of disorders characterized by the overproduction of eosinophils, which can lead to organ damage if not treated promptly.
- Churg-Strauss syndrome: A rare autoimmune condition that can cause eosinophilia, asthma, and vasculitis, potentially leading to severe organ damage.
- Lymphoma: Certain types of lymphoma, such as Hodgkin's lymphoma and some non-Hodgkin's lymphomas, can present with eosinophilia.
- Rare Diagnoses
- Tropical pulmonary eosinophilia: A condition seen in some individuals infected with filarial parasites, characterized by eosinophilia and pulmonary symptoms.
- Eosinophilic granuloma with polyangiitis (EGPA): Formerly known as Churg-Strauss syndrome, but when it presents without asthma, it's considered under this category.
- Idiopathic hypereosinophilic syndrome: A condition of unknown cause characterized by persistent eosinophilia and organ damage.
Each of these diagnoses has a distinct set of clinical features and diagnostic criteria. A thorough medical history, physical examination, and laboratory tests, including blood counts and sometimes bone marrow biopsy, are essential for determining the underlying cause of eosinophilia.