Haemophilus influenzae type b necrotizing fasciitis in an adult with common variable immunodeficiency

Necrotizing fasciitis of an extremity due to Haemophilus influenzae is exceptionally uncommon in adults, particularly since the advent of widespread vaccination with conjugated H. influenzae type b (Hib). We report a previously vaccinated, 39-year-old male with a history of common variable immunodeficiency (CVID), poorly compliant with intravenous immunoglobulin (IVIG) therapy, who required emergent treatment for left leg necrotizing fasciitis. The patient was initially treated with piperacillin-tazobactam, vancomycin, and clindamycin, in tandem with surgical debridement and wash-out. The patient responded well and completed a 2-week course of ceftriaxone following blood culture results that demonstrated beta-lactamase-positive Hib. This is the fifth documented case of necrotizing fasciitis caused by H. influenzae, and the first affecting an adult with prior Hib vaccination. This case highlights the importance of IVIG compliance for CVID patients and advocates considering encapsulated organisms as part of the differential diagnosis for severe skin and soft tissue infections in this patient population.