17. Eosinophilia
Eosinophilia can result from both intrinsic hematologic disorders as well as secondary to a variety of systemic disorders and allergens, including drugs [82]. Drugs most commonly associated have included penicillins, sulfas, allopurinol, phenytoin, carbamazepine, and gold. Drug Rash with Eosinophilia and Systemic Symptoms (DRESS syndrome) describes the association of eosinophilia with rash, fever, and visceral involvement, such as pneumonitis, hepatitis, nephritis, adenopathy, or carditis [83]. DRESS has been associated most commonly with antibiotics, and anticonvulsants, but other agents have also been implicated.