Miscellaneous Diseases

Many diseases do not fall into any of the above categories as their mechanisms are different. Of these the most common are the allergic diseases. The term “allergy” means sensitivity of the body to foreign substances particularly protein in nature. By previous contact the body develops sensitivity against foreign proteins (antigens) and certain chemical complexes termed anti-bodies are formed within the body. Further contact with the specific protein produces what is called an antigen antibody reaction, due to these two complexes combining and the effect of such a reaction varies from mild urticaria (itching skin eruptions) to fatal shock. Such diseases like asthma, urticaria, rheumatic fever and certain kidney diseases are allergic in origin. Quite often a particular food or a drug may be the cause of an allergy. It is now known that antibodies can even be produced against the person’s own tissue proteins and can give rise to disease. Such diseases are termed “auto immune diseases”.