Etiology

• Impaired hematopoiesis
• Drug-induced
  • Antithyroid
    • Methimazole
    • Propylthiouracil
  • Anti-inflammatory
    • Sulfasalazine
    • Methotrexate
  • Psychotropic or anticonvulsant
    • Clozapine
    • Carbamazepine
    • Phenytoin
  • Cardiovascular
    • Antiarrhythmic agents (eg, procainamide)
    • Ticlopidine
  • Antimicrobial
    • Trimethoprim-sulfamethoxazole
    • Quinine
    • Acyclovir

Drug-induced neutropenia most often presents with oropharyngeal ulcers and fever (ie, mucus membrane infection).