Cat scratch disease is an infectious disease said to be caused by the batonella bacteria. This disease is transmitted by bites or scratches of cats or by exposure to cat saliva. The diease is said to be caused by a bacteria called Bartonella henselae. It spreads through contact with a bite or scratch of an infected cat or contact with saliva of the cat on the white of the eye or broken skin.A swelling of the lymph node takes place at the area of the bite or scratch after 2-3weeks of getting infected. The infected lymph node may turn into a tunnel through the skin and leak the fluid. This disease is commonly seen in children and is the main cause for the swelling of lymph nodes.