A preliminary investigation into the risk factors associated with cellulitis of the lower limb

Cellulitis is an infective/inflammatory skin condition costing 426,000 bed days per year. The legs are most frequently affected and 18-20% of patients suffer from recurrent attacks. Bacteria are thought to be causal but are rarely identified, therefore antibiotic treatment is empirical and currently the only means of prophylaxis. Previous studies have cited athlete’s foot, skin vulnerability and oedema as risk factors for cellulitis and there may also be a relationship with the immune response. This preliminary study was designed to evaluate these risk factors and identify areas for further investigation.Patients were matched with controls (N = 12 + 12 controls) by age, sex and mobility. Participants attended twice (during treatment and again 6 weeks after clinical resolution). Foot scrapings were cultured to examine the flora and blood samples taken to determine white cell types and numbers, cytokine levels and markers specific to fungal infection. Physiological measurement techniques were used to assess skin function. Psychological stress levels were evaluated and medical history recorded.Fewer dermatophytes were grown from the feet of patients as compared to matched controls. Amongst patients blood profiling showed evidence of increased neutrophil count post episode and levels of IL-12 and IL-8 also reached near significance in this group. Physiological tests for skin blood flow, water loss and pH produced results consistent with cellulitic skin but persisting oedema was significantly higher in the patient group and characterised by loss of structure in the dermal tissues. Ipsilateral injuries, allergies, history of other bacterial infections, excessive life time prescription of antibiotics and levels of psychological stress, evaluated by a questionnaire, were also found to be significantly higher in the patient group. No evidence was produced to show any differences between acute and recurrent populations.This preliminary study into the potential risk factors for cellulitis indicates that some factors merit further investigation. Larger studies are required to substantiate results