Dermatologycommon
A 78-year-old man presents with three weeks of redness, warmth and itch affecting both lower legs. He is otherwise well, with long-standing varicose veins and ankle swelling that worsens by evening. On examination he is afebrile; both shins are red and mildly scaly, with brownish discolouration of the skin above both ankles and pitting oedema. White cell count and C-reactive protein are normal. He was treated twice in the past year with antibiotics for the same problem, without lasting improvement. Which one of the following is the most likely diagnosis?