Impetigo Summary Impetigo is a skin infection caused by bacteria. It is usually caused by staphylococcal (staph) bacteria, but it can also be caused by streptococcal (strep) bacteria. It is most common in children between the ages of two and six. It usually starts when bacteria get into a break in the skin, such as a cut, scratch, or insect bite. Symptoms start with red or pimple-like sores surrounded by red skin. These sores can be anywhere, but usually they occur on your face, arms and legs. The sores fill with pus, then break open after a few days and form a thick crust. They are often itchy, but scratching them can spread the sores. Impetigo can spread by contact with sores or nasal discharge from an infected person. You can treat impetigo with antibiotics. NIH: National Institute of Allergy and Infectious Diseases National Institute of Allergy and Infectious Diseases Find an Expert American Academy of Dermatology American Academy of Dermatology National Institute of Allergy and Infectious Diseases National Institute of Allergy and Infectious Diseases National Institute of Arthritis and Musculoskeletal and Skin Diseases National Institute of Arthritis and Musculoskeletal and Skin Diseases Clinical Trials ClinicalTrials.gov: Impetigo National Institutes of Health Array Ecthyma Impetigo Related Issues Group A Streptococcal Infections National Institute of Allergy and Infectious Diseases Staph Infections Nemours Foundation Start Here Impetigo Nemours Foundation Impetigo American Osteopathic College of Dermatology Impetigo National Institute of Allergy and Infectious Diseases Impetigo Logical Images Impetigo Mayo Foundation for Medical Education and Research Impetigo American Academy of Pediatrics Impetigo: A Common Skin Infection among Children American Osteopathic Association Teenagers Impetigo Nemours Foundation Children Impetigo Nemours Foundation Treatments and Therapies Impetigo Care American Academy of Pediatrics Journal Articles Impetigo