Löffler's syndrome is a disease in which eosinophils accumulate in the lung in response to a parasitic infection. The parasite can be Strongyloides stercoralis, Dirofilaria immitis or Ascaris which can enter the body through contact with the soil. The symptoms of Löffler's syndrome include those of a parasitic infection such as irritable bowel syndrome, abdominal pain and cramping, skin rashes and fatigue. Löffler's syndrome itself will cause difficulty breathing, coughing as well as a fever. Löffler's syndrome is a disease in which eosinophils accumulate in the lung in response to a parasitic infection. The parasite can be Strongyloides stercoralis, Dirofilaria immitis or Ascaris which can enter the body through contact with the soil. The symptoms of Löffler's syndrome include those of a parasitic infection such as irritable bowel syndrome, abdominal pain and cramping, skin rashes and fatigue. Löffler's syndrome itself will cause difficulty breathing, coughing as well as a fever. The diagnosis of Loffler’s syndrome can be challenging, as the diagnostic criteria can be vague and consistent with a multitude of diseases or conditions. The disease's developmental trajectory is mostly unknown. Upon examination of symptoms, a provider will likely request a chest x-ray looking for migratory pulmonary infiltrate, and blood testing, to confirm a diagnosis. Symptoms tend to be brief, but can range from mild to severe and include: fever, vomiting, increased respirations or difficulty breathing, cough, wheeze, and rash. Symptoms typically follow an exposure to allergens or certain drugs, and last approximately two weeks. Eosinophilia is the main feature of diagnostic criteria for Loffler’s syndrome. Eosinophils are white blood cells that fight infection by destroying foreign substances in the body. This increase is determined through a blood test called a complete blood count, or CBC. A result of over 500 cells/mcL (cells per microliter of blood) is considered elevated. The normal range for eosinophils is less than 350 cells/mcL.