An angioedema, also known as angioneurotic oedema, affecting the right side of a tongue. Angioedema is similar to urticaria and characterised by large swellings in the skin, larynx and other areas. The most common cause is a sudden allergic reaction to food such as eggs, strawberries or seafood and less commomly to drugs and insects bites. Angioedema may cause difficulty in breathing and speaking. If respiration is threatened it is treated with adrenaline and with antihistamine drugs in less severe cases.