Cheilitis is clinically characterised by an acute or chronic inflammatory state of the lips, limited to the vermillion border. The term "angular" cheilitis applies to localise bilateral lesions of the angles of the mouth. Acute cheilitis is erythematous or erosive, accompanied by a stinging sensation. Chronic cheilitis is for the most part erythemato-squamous, and is often asymptomatic. The classification of cheilitis is based on the aetiology, being most often an allergy, an infection or a physical irritation, potentially favourised by particular anatomical conditions. However, the distinction between the diverse types is sometimes blurred as diverse causes can co-exist.