Severe Lower Extremity Cellulitis Caused By An Unusual Pathogen: Haemophilus Influenzae Type F

We present a case of unusual cellulitis of the lower extremities caused by Haemophilus influenzae (HI). A 64-year-old female with human immunodeficiency virus (HIV) with a suppressed viral load on treatment, presented with severe, very painful cellulitis of her lower extremity. CT scan did not show any gas or collections; however, she was taken to the operating room for concern of necrotizing fasciitis but no evidence of deep tissue involvement was found. Blood culture and wound culture were positive for HI type F (HiF), a newly emergent pathogenic capsulated HI that has emerged post-HI type B (HiB) vaccination.