Cat scratch disease, also known as catscratch disease, cat scratch fever, or subacute regional lymphadenitis, produces symptoms due to bacterial infection of the lymph nodes with bacteria known as Bartonella henselae. Most patients have a history of exposure to cats, and the disease begins with a reddish brown nodule (bump) at the site of infection. There is typically no pain or tenderness. Over the next weeks, there is enlargement of the lymph nodes that may be accompanied by tenderness. About half of patients have other symptoms like fever, malaise, joint pains, loss of appetite, fatigue, headache, and sore throat. Other less common symptoms that have been reported include rash, weight loss, seizures, mental status changes, numbness and tingling of the extremities, and irritation of the eyes.