Allergology and immunology are the branches of medical science concerned with all the disorders that can affect the immune system. The body's immune system fights infections that can be caused by bacteria, viruses, fungi and parasites. Allergy, a symptom of the body's hyper-sensitivity, is another of these disorders.
The allergist and clinical immunologist knows about the various substances in the environment and in food that can trigger an allergy. Examples of allergic reactions include seasonal and perennial rhinitis (e.g. hay fever), skin disorders such as eczema and neurodermitis, and metabolic disorders, where patients react to certain types of cereals with diarrhoea, vomiting or by suffering damage to the mucous membrane of the intestine.
The doctor conducts a variety of blood and skin tests (e.g. a prick test) to diagnose an allergy. This is followed by treatment using appropriate medicines. He also advises the patients on how they can protect themselves from allergies.