Cellulitis is a common skin infection caused by bacteria. Staphylococcus and streptococcus bacteria are the most common causes of cellulitis. Normal skin has many types of bacteria living on it. When there is a break in the skin, these bacteria can cause a skin infection. Treatment for uncomplicated cellulitis is usually for 10 to 14 days but antibiotics should be continued until all signs of infection have cleared (redness, pain and swelling) – sometimes for several months. Oral antibiotics used commonly are penicillin, flucloxacillin, dicloxacillin, cefuroxime or erythromycin.