Disseminated blastomycosis in pregnancy presenting with arthritis and cutaneous lesions

Blastomycosis is a rare fungal infection, and disseminated disease in pregnancy is exceedingly uncommon. We report a 26-year-old primigravida at 28 weeks' gestation who presented with progressive knee arthritis and erythematous nodular skin lesions. Skin biopsy and synovial fluid culture confirmed blastomyces dermatitidis. She was treated initially with liposomal amphotericin B but transitioned to itraconazole due to electrolyte abnormalities. Despite complications of severe knee pain and hypokalemia, she improved clinically. At 39 weeks, she underwent induction of labor and cesarean delivery for obstetric indications. The infant was healthy, and placental pathology showed mild villitis without fungal elements. The mother completed 12 months of itraconazole therapy with full remission. This case highlights the importance of considering disseminated fungal infections in pregnancy and adds to the limited literature on maternal and neonatal outcomes of blastomycosis.