From www.merck.com: The Merck Manual - Home Edition. Erysipelas Erysipelas is a skin infection caused by Streptococcus. Most commonly, the infection appears on the face, arm, or leg; sometimes, it begins where the skin is broken. A shiny, red, slightly swollen, tender rash develops, often with small blisters. Lymph nodes around the infected area may become enlarged and painful, and people with particularly bad infections develop a fever and chills.