Adult-Onset Still's Disease Presenting as Macrophage-Activation Syndrome With Critical Illness in the Third Trimester of Pregnancy: A Case Report.

We report a case of a young woman with adult-onset Still's disease presenting as macrophage-activation syndrome complicated by shock and respiratory failure during the third trimester of pregnancy. CASE SUMMARY: A previously healthy 26-year-old woman at 35 weeks of gestation presented with 1 week of constitutional symptoms and was found to be febrile, tachycardic, and hypotensive. She delivered a healthy neonate by cesarean section. Following delivery, she had worsening hypotension and fevers despite fluid resuscitation and antibiotics, and developed progressive hypoxemia requiring up to 60% Fio

conclusionTo our knowledge, this is the first report of new-onset adult-onset Still's disease during the third trimester of pregnancy, which presented as macrophage-activation syndrome. In the context of late pregnancy, macrophage-activation syndrome can mimic or raise concern for hemolysis, elevated liver enzymes, and low platelet syndrome and other peripartum disorders. Furthermore, the characteristic articular symptoms of adult-onset Still's disease may be mild and/or delayed, and pulmonary involvement with severe hypoxemia can occur. Clinicians should consider this diagnosis when evaluating a pregnant patient with unexplained fever and multiorgan dysfunction.