African Tick Bite Fever

Dr. Westwood presented a great case of a patient who had just returned from traveling on Safari to Sub-Saharan Africa who presented with acute fevers, chills, drenching night sweats and an exquisitely painful erythematous/violacious left first metatarsal rash. He was initially admitted to the vascular surgery service and underwent CTA of the lower extremity and TTE without evidence of thrombus and was started on cefazolin and a heparin drip. Over the course of the next coming days, his cellulitis quickly spread more proximally and he was started on vancomycin and piperacillin tazobactam. Unfortunately, despite broad spectrum antibiotics, the erythema continued to spread and inflammatory markers continued to rise. General surgery had also evaluated the patient and did not feel like he warranted a surgical intervention?

What’s your summary statement and what’s your differential for a worsening cellulitis despite broad spectrum antibiotics?

We don’t see these types of things very often. Here’s a resource to help us form our differential


ID and dermatology was consulted. ID recommended starting the patient on doxycycline for atypical coverage. A skin biopsy revealed: neutrophilic dermatitis with vascultitis + papillary edema with ? ecthyma, negative for bacterial/fungal/AFB. After addition of doxycycline, his rash started to regress. 2 weeks later, a broad range PCR returned positive for Rickettsia Africae