Leprosy

 Leprosy is a disease which affects the skin and mucus membranes which causes the skins surface to form lumps and discolouration.  It is caused by an intracellular infection by the bacteria Mycobacterium leprae.  The body responds in two different ways to this infection whic causes different outcomes 

1) Tuberculoid leprosy - the body produces a strong T_H1 response which kill alot of the bacteria and the disease progresses slowly 

2) Lepromatous leprosy - the body produces as strong TH2 antibody response which leave a lot of macrophages infected with the bacteria as as antibodies are not a good response to an intracellular infection.  As a result this form of leprosy is fata