16th July 2026

Erysipelas

Erysipelas is a superficial bacterial skin infection affecting the upper dermis and lymphatics. It is caused almost exclusively by Streptococcus pyogenes (Group A streptococcus)

It presents with sudden-onset fever, chills, and a well-demarcated, raised, bright red rash. The face and lower limbs are most commonly affected. Risk factors include breaks in the skin barrier, lymphoedema, obesity, and immunosuppression.

Diagnosis

Diagnosis is clinical. Blood cultures may be taken in systemic illness. Differential diagnoses include cellulitis, DVT, contact dermatitis, and drug reactions.

Management

• Oral phenoxymethylpenicillin (or flucloxacillin) for mild cases
• IV benzylpenicillin or flucloxacillin for systemic features
• Clarithromycin if penicillin-allergic