Cyclic Fevers in Pregnancy: A Case of Parvovirus-Related Hemophagocytic Lymphohistiocytosis.

Parvovirus B19 typically causes mild symptoms in healthy adults, including fever, rash, and arthralgias. Certain immunocompromised adult populations, including those with immunodeficiencies or hematologic disease, are at risk of clinically significant complications, including transient aplastic crisis. Further, in pregnant patients, there is a risk of transplacental viral transmission, which may lead to severe fetal anemia, nonimmune hydrops fetalis, and intrauterine fetal demise. The clinical course of parvovirus B19 in pregnant patients with underlying hematologic disease has not been well reported. In this case report, we present a 27-year-old pregnant patient with sickle cell beta thalassemia who was infected with parvovirus B19 at 20 weeks of gestation. She experienced a prolonged hospitalization characterized by persistent maternal vaso-occlusive crisis with concomitant transient aplastic crisis. There was suspected vertical transmission of the virus, leading to concern for severe fetal anemia and termination of the pregnancy. The patient continued to have cyclic fevers, bicytopenia, and a constellation of laboratory findings leading to a diagnosis of postviral hemophagocytic lymphohistiocytosis (HLH). She was successfully treated with pulse dose corticosteroids and an Interleukin-1 receptor antagonist with subsequent improvement of her symptoms and laboratory markers. This report highlights the distinct diagnostic and management challenges of parvovirus B19 in pregnant patients with comorbid hematologic disease, including a rare but serious sequela of the infection, and the risk for severe maternal and fetal complications.