My father was diagnosed with Parkinson's about three years ago. I've posted a few messages on this list a while back, but haven't been active for a long time. I apologize for the length of this post, and the off topic content. I'm just hoping that someone may have some idea and be able to offer some advice. About four weeks my father was diagnosed with Pneumonia and give an antibiotic that seemed to clear it up. A few days later he started having a fever again. It was around 103. He was admitted to the hospital, given another antibiotic, and released the following day because his temperature returned to normal. The next day his fever returned and increased over the next couple of days back to over 103. He was again admitted to the hospital. They continued to run test, but were unable to find anything. Over the next few days his temperature would rise to around 104, and then fall back to normal again, usually in the morning. The highest his temperature got was 104.7. After a week he was release because his fever was normal for 24 hours. He was to continue on the latest antibiotic IV that he was given for another week. A nurse was sent to our house every 8 hours to administer the IV and teach us how to do it. On the third visit, the nurse noticed his heart rate and respiratory rate were unusually high, and he seemed more dazed and out of it than is usual for him. Although his temperature was normal, she decided to call an ambulance. He was again admitted to the hospital. The following day his temperature went up to 103. That was a week from last Sunday. Since then his temperature has continue to fluctuate between normal and 104. The have continued to run blood test, cat scans, and even did a bone marrow biopsy. All test have returned negative. Last night his temperature rose to 105.9. He was given Motrin, Tylenol, Naproysn and put under a cooling blanket. Over the next few hours his temperature slowly declined. As of now it appears that the Doctors do not believe they will find a cause for the fever. He is scheduled for some more tests, including an MRI and possible a spinal tap. The Doctors had considered a Liver biopsy, but don't feel that is going to show anything and have decided against doing one. I have been doing some research on the internet and found a document on a case of Fever of Unknown origin that turned out to by Intravascular Lymphoma. It appears that the Bone Marrow would show that, but the document also said that this doesn't affect bone marrow until the late stages. My question is, could it be possible that he has Intravascular Lymphoma even though the Bone Marrow test showed nothing? I also read about Temporal Arteritis as causing Fevers. Is it possible that this could be un-detected? I know this is off topic, but I'm getting the impression that the Doctors have pretty much given up and believe that this will eventually be fatal. Any suggestions would be welcome.