can anyone explain the difference between an allargy and an intolerance to a substance. I had been feeling awful for some time and finally realised it was a reaction to milk. I stopped using it and after two weeks felt amazingly well. I have since tried to have it and the reaction was severe...it puts me into an almost comatose state!!
An allergy is an immune system response to something, whereas an intolerance is when a body has an inability to digest a particular food, like milk (lactose intolerance) or wheat products (coeliac disease). With an intolerance, the result is usually diarrhoea, if the 'forbidden' food is eaten.
An allergy is likely to have potentially fatal consequences if the person does not have immediate medicla help (such as with nuts). An intollerance will not cause death but can leave the individual in pain or discomfort.