Objectives: To describe clinical and biological characteristics and to evaluate sensitivity of bacteria to antibiotics in pyodermatitis at Dermatology Department in Thai Nguyen Central General Hospital. Methods: 30 patients were diagnosed with pyodermatitis treated at Dermatology Department in Thai Nguyen Central General Hospital from April, 2010 to October 2010. The study describes clinical and biological characteristics and secretion fluid in wounded area taken for antimicrobial assay (according to a routine technique) to be done before treatment with topical applying of blue methylene 2 percent and systematic antibiotics of Cephalosporin. After 7 days of treatment, evaluating sensitivity of bacteria to antibiotics and appropriateness between results in vitro and clinical results treated with antibiotics. Results: Pyodermatitis was commonly seen in children under 5 years (83.3 percent)
clinical symptoms are: pustulation (100 percent), local itching (93.3 percent) and ulceration (86.7 percent). The common sites were on the head, the face and the neck (96.7 percent). Impetigo accounts for 73.3 percent of pyoderma titis. Increased white blood cells accounted for 80 percent of cases
abnormal urine was 12 percent of patients. Bacterial culture: 100 percent of cases were S. aureus
20 percent of them sensitivity to cefotaxime. However, 76.7 percent of patients treated with cefotaxime had good results and coefficient of Kappa = 0.04 (a little appropriateness). Conclusion: One third of bacteria resist to Cefotaxime in vitro. However, clinically, it was still used in treatment of pyodermatitis with good result.