Diabetic Foot Infection

Key considerations: Osteomyelitis, Necrotizing fasciitis, Charcot neuroarthropathy

Cannot miss

history: Duration, prior infections, vascular history, glucose control, neuropathy symptoms; exam: Probe-to-bone test, depth assessment, vascular exam (pulses, ABI), neuropathy assessment; labs: CBC, BMP, ESR, CRP, HbA1c, blood cultures if systemic; Wound culture (deep tissue preferred over superficial swab); imaging: X-ray (osteomyelitis: periosteal reaction, bone destruction); MRI for soft tissue extent and osteomyelitis evaluation; ABI/vascular studies; bedside: Probe-to-bone test, monofilament testing

immediate: Systemic infection: IV antibiotics (vancomycin + piperacillin-tazobactam); Urgent surgical debridement if abscess, necrosis, or compartment syndrome; general: Mild: oral antibiotics (amoxicillin-clavulanate or TMP-SMX + fluoroquinolone); Offloading (total contact cast or specialized footwear); Glucose optimization; Osteomyelitis: 6 weeks IV antibiotics or surgical resection; Vascular assessment for revascularization if ischemic

admit: Moderate-severe infection, systemic sepsis, need for surgical debridement; discharge: Mild infection with close follow-up in 48-72hr; consults: Surgery/podiatry for debridement, vascular surgery if ischemic, ID for osteomyelitis

Probe-to-bone: if a sterile probe reaches bone through a diabetic ulcer, probability of osteomyelitis is ~90%
ESR >70 is strongly suggestive of osteomyelitis in diabetic foot
Charcot foot: acute red, hot, swollen foot in a neuropathic patient WITHOUT infection — immobilize immediately