A Quick Synopsis of AFP's "Diabetic Foot Infections"

Diabetic Foot Infections
FASSIL W. GEMECHU, MD, MetroHealth Medical Center, Cleveland, Ohio, FNU SEEMANT, MD, State University of New York at Buffalo, Buffalo, New York, CATHERINE A. CURLEY, MD, MetroHealth Medical Center, Cleveland, Ohio
Am Fam Physician. 2013 Aug 1;88(3):177-184.
 http://www.aafp.org/afp/2013/0801/p177.pdf

     There is up to a 25% risk of a diabetic developing a foot ulcer in their lifetime. Risk factors include peripheral neuropathy, PAD, and impaired immunity. The most common bacteria in foot ulcers are aerobic gram negative rods, mostly Staphylococcus (including MRSA). Moderate to severe foot ulcers are often polymicrobial, including gram negative bacilli. Necrotic ulcers are more commonly anaerobic.
   A diabetic foot ulcer will have redness, warmth, swelling, pain, tenderness, purulent secretions, and induration. The wound severity can be graded. Grade 1 is for ulcers that are local without any systemic features. Grade 2 is a local infection with erythema less than 2 cm around the wound. Grade 3 has erythema greater than 2 cm around the wound which also affects structures below the skin and subcutaneous area. Grade 4 has signs of SIRS (fever, tachycardia, elevated respiratory rate, or leukocytosis).
     Ulcers that are larger than 2 cm or deeper than 3 mm or over a bony prominence should be investigated for osteomyelitis. Suspicious wounds can be diagnosed by biopsy, x ray, bone scan, or MRI. Probing the ulcer to see if it hits the bone is another option. Although lab values such as ESR, CRP and leukocyte counts may be elevated, absence of these markers does not exclude infection.
     Mild infection can be treated with oral antibiotics  for 1-2 weeks as an outpatient. Reevaluation should occur within 2-4 days.  More severe infections will need empiric broad spectrum antibiotics for 2-3 weeks. Hospitalization should be considered. Blood cultures should be drawn and the patient should be reassessed daily. If the patient does not improve, surgery should be consulted for the possibility of revascularization or amputation.
     Diabetic patients should have their feet routinely inspected at least annually. Patients with sensory loss should have them inspected every 3-6 months. Patients with PAD should have them looked at every 2-3 months. A patient with a history of ulcers should have their feet inspected every 1-2 months.