A 57 year old male presents with a 2 week history of a sore mouth and is concerned about the appearance of his tongue. He is maintaining his oral intake as normal. Past medical history includes well controlled Asthma and Eczema, which he describes has flared up again recently on his arms and ankles. Drug history includes Salbutamol and Beclometasone inhalers, Diprobase cream and Hydrocortisone cream. He is a non-smoker.
What is the most likely diagnosis?