Drugs

• Trimethoprim-sulfamethoxazole

• Pentamidine

• Pyrimethamine

• Ganciclovir

• Fluconazole

• Alpha-interferon

• Rifabutin

• Clarithromycin

• Didanosine

• Amphotericin B

• Indinavir

• Ritonavir

• Delavirdine

• Nelfinavir

Deficiencies

• Folate

• Vitamin B₁₂

Infection

• HIV

• Parvovirus B19

• Mycobacterium avium complex (MAC)

• Mycobacterium tuberculosis

• Histoplasma capsulatum

• Bartonella henselae (bacillary angiomatosis)

Neoplasia

• Non-Hodgkin’s lymphoma

Miscellaneous

• Preexisting condition

Immune thrombocytopenic purpura

Thrombotic thrombocytopenic purpura

Hypersplenism

• Infection

• Hemophagocytosis

• Cirrhosis

Drugs

• Saquinavir

• Interferon