Diabetic foot osteomyelitis: usefulness of erythrocyte sedimentation rate in its diagnosis.

BACKGROUND: Recently, ESR was reported to have a useful diagnostic value in detecting diabetic osteomyelitis. The test has been performed in a limited number of patients. This laboratory parameter is simple and could be routinely performed in developing countries where diabetes and its complication are increasingly being encountered.

OBJECTIVE: To evaluate the reliability of erythrocyte sedimentation rate (ESR) in differentiating diabetic osteomyelitis from cellulitis, and to compare its diagnostic value with other hematological indices.

METHODS: In a one-year prospective study, forty -three adult diabetic patients with foot ulcers were assessed at King Abdulaziz University Hospital Diabetes Center Riyadh from 1st January to 31st December 2005. ESR was compared with other hematological profiles in differentiating osteomyelitis from cellulitis.

RESULTS: ESR, white blood cell count (WBC), platelet count, and red cell distribution width (RDW) were higher in patients with osteomyelitis than in patients with cellulitis (p<0.0001 for ESR; others p<0.05). In contrast, haematocrit and haemoglobin levels were lower in patients with osteomyelitis than in patients with cellulitis (p<0.0001). Overall, the efficiency of the haematological parameters in correctly diagnosing diabetic osteomyelitis from cellulitis was highest for ESR > 70 mm/hr (92%), followed by haematocrit < 36% (89%), haemoglobin < 12 g/dl (85%), platelet count > 400x10(9) (69%), RDW > 14.5 (65%), and WBC >11x10(9) (63%).

CONCLUSION: It is concluded that of the haematological parameters, ESR has the best diagnostic discrimination between diabetic foot osteomyelitis from cellulitis. Further studies on larger population in this environment are however indicated.