Detection, management, and prevention of diabetes-related foot disease in the Australian context

Table 1 International Working Group on the Diabetic Foot risk categories[8]

Risk category	Ulcer risk	Characteristics	Frequency
0	Very low	No LOPS and no PAD	Once a year
1	Low	LOPS or PAD	Once every 6-12 mo
2	Moderate	LOPS and PAD, or LOPS and foot deformity, or PAD + foot deformity	Once every 3-6 mo
3	High	LOPS or PAD and one of the following: History of foot ulcer, a previous LEA, end-stage renal disease	Once every 1-3 mo

LEA: Lower extremity amputation; LOPS: Loss of protective sensation; PAD: Peripheral arterial disease.

Table 2 Common bacteria involved in diabetic foot infections according to infection grade, adapted from the International Working Group on the Diabetic Foot infection guidelines[47]

IWGDF classification	Recommended empirical cover
	Gram-positive (MSSA, Streptococcus spp.)	Gram-negative (enteric, non-pseudomonal)	Obligate anaerobes	MRSA	Pseudomonal
Mild (grade 2) – no recent antibiotics	Yes	No	No	If at risk1	No
Mild (grade 2) – recent antibiotics or water-immersed wound	Yes	Yes	Consider if chronic	If at risk1	No
Moderate (grade 3)	Yes	Yes	Consider	If at risk1	Tropical climates or recently cultured
Severe (grade 4)	Yes	Yes	Yes	If at risk1	Yes

¹Risk factors for methicillin-resistant Staphylococcus aureus (MRSA) include previous colonisation with MRSA, residence in a community, aged-care facility, or correctional facility with high MRSA prevalence, and frequent or prolonged stay in a hospital with a high prevalence of MRSA.

IWGDF: International Working Group on the Diabetic Foot; MSSA: Methicillin-susceptible Staphylococcus aureus; MRSA: Methicillin-resistant Staphylococcus aureus.

Table 3 Spectrum of select antibiotics against common bacteria involved in diabetic foot infections, adapted from the International Working Group on the Diabetic Foot infection guidelines[47]

Antibiotic	Antibiotic spectrum					Oral dose frequency	Pill burden (per day)
	Gram-positive (MSSA, Streptococcus spp.)	Gram-negative (enteric, non-pseudomonal)	Obligate anaerobes	MRSA	Pseudomonal
Penicillins, anti-staphylococcal1	Yes	No	No	No	No	4	4-8
Cefalexin	Yes	Some	No	No	No	4	4-8
Amoxicillin-clavulanate	Yes	Yes	Yes	No	No	2	2
Trimethoprim-sulfamethoxazole	Yes	Yes	No	Some2	No	2	2
Doxycycline	Yes	Some	No	Some2	No	2	2
Clindamycin	Yes	No	Yes	Some2	No	3-4	9-16
Metronidazole3	No	No	Yes	No	No	2-3	2-3
Cefazolin	Yes	Some	No	No	No
Ceftriaxone	Yes	Yes	No	No	No
Piperacillin-tazobactam	Yes	Yes	Yes	No	Yes
Cefepime	Yes	Yes	No	No	Yes
Meropenem	Yes	Yes	Yes	No	Yes
Vancomycin	Yes	No	No	Yes	No
Moxifloxacin	Yes	Yes	Yes	Some2	No	1	1
Ciprofloxacin4	No	Yes	No	No	Yes	2	2

¹Includes flucloxacillin, dicloxacillin, and nafcillin.

²Some methicillin-resistant Staphylococcus aureus (MRSA) strains are resistant, however, in mild cases these oral MRSA-active antibiotics may be considered empirically for patients with MRSA risk.

³Metronidazole should not be used as a single agent, it is often combined with other antibiotics to add anaerobic activity to the regimen.

⁴Ciprofloxacin should not be used as a single agent empirically given the lack of Gram-positive cover, it is often combined with other antibiotics such as clindamycin or vancomycin.

MSSA: Methicillin susceptible Staphylococcus aureus; MRSA: Methicillin-resistant Staphylococcus aureus

Table 4 Empirical antibiotic choices in diabetes-related foot disease; adapted from the International Working Group on the Diabetic Foot infection guidelines[47]

IWGDF classification	Example of Empirical Antibiotic	If MRSA Risk1
Mild (grade 2) – no recent antibiotics	Flucloxacillin PO, or cefalexin PO	As a single agent clindamycin PO, or trimethoprim-sulfamethoxazole PO, or doxycycline PO
Mild (grade 2) – recent antibiotics or water-immersed wound	Amoxicillin-clavulanate PO	Add one of the agents above, OR as a single agent moxifloxacin PO
Moderate (grade 3)	Amoxicillin-clavulanate PO/IV	Add one of the agents above, or if IV required, add vancomycin IV
	Or cefazolin IV plus metronidazole PO/IV
	Or if Pseudomonas risk2, piperacillin-tazobactam IV
Severe (grade 4)	Piperacillin-tazobactam IV	Add vancomycin IV

¹Risk factors for methicillin-resistant S. aureus (MRSA) include previous colonisation with MRSA, residence in a community, aged-care facility, or correctional facility with high MRSA prevalence, and frequent or prolonged stay in a hospital with a high prevalence of MRSA.

²Risk factors for Pseudomonas infection include positive Pseudomonas microbiology in previous few weeks or located in a tropical/sub-tropical climate area.

IV: Intravenous; IWGDF: International Working Group on the Diabetic Foot; MRSA: Methicillin-resistant Staphylococcus aureus; PO: Oral.