INTRODUCTIONCellulitis is a spreading bacterial infection of the dermis and subcutaneous tissues. It occurs among both men and women. 1 The incidence of lower limb cellulitis was reported relatively high with 199 cases per 100,000 person-years in a population based study. 2 The most common causative organisms are Streptococcus pyogenes and Staphylococcus aureus. 3 The risk factors are toe web intertrigo, leg ulcers, trauma causing breach in the skin continuity, venous insufficiency, lymphedema, diabetes, obesity and immuno-compromised conditions. The most common risk factors for recurrence are venous insufficiency and lymphedema and previous episode of cellulitis. 4 The most common pathogenesis is the breach in skin integrity especially the toe web space. The Streptococci and Staphylococci produce toxins which cause inflammatory mediator release, resulting in the edema and skin changes.5 If the infection is persisting in the subcutaneous plane, the edema worsens leading to local complications resulting in systemic sepsis and multiple organ dysfunction. The common clinical ABSTRACT Background: Cellulitis, an infection of skin and subcutaneous tissue is usually managed conservatively and surgical intervention is required for local complications. The aim of this study was to correlate the subcutaneous pressure with the need for early surgical intervention in cases of lower limb cellulitis. Methods: We prospectively measured subcutaneous pressures in the normal leg and in the leg with cellulitis. Patients managed with parenteral antibiotics were compared to those managed with parenteral antibiotics and surgical intervention with standard statistical tests. Results: The median subcutaneous pressure was 3 mmHg and 9 mmHg in the normal leg and the other with cellulitis respectively. The mean of difference in subcutaneous pressure in legs with cellulitis compared to normal legs was 5.93 mmHg and 8.29 mmHg in the conservative group and surgical intervention group respectively. The difference in subcutaneous pressure between the normal leg and in the leg with cellulitis was statistically significant (p<0.001). The difference in the average pressure between surgical intervention group and conservative group was 2.36 mmHg and was statistically significant (p<0.05). The optimal threshold (difference in pressure) was identified as >=7 with sensitivity of 85.7% and specificity of 57.1%. Area under the ROC curve (SE) was 0.71 (0.10) with 95% CI (0.51, 0.87).
Conclusions:The subcutaneous pressure in leg with cellulitis is a predictor for the need for early surgical intervention. It can be used as an adjunct in management and clinical decision making for cases of cellulitis of lower limbs.