Hello, I read your message and understood your medical problem. I see your friend has a swollen lymph node around his neck and bitter taste in the mouth for the last two weeks. He has no headache, no loss of appetite, no skin rash, just chills. Usually, a swollen lymph node in the neck is linked to an infection or some inflammatory causes like lupus and arthritis. The sensitivity to some medications can be another cause. Rare cases are in some types of cancer but this is not the first opinion to come in our minds. As the chills are present along with the swollen lymph node, an infection is much more probable to be the cause. To determine the exact cause your friend must see a doctor to do some check-ups and a complete physical examination. You may need specific tests if necessary. Don t forget to mention to the doctor other symptoms that may be present or developed recently and tell him about drugs and special health conditions. Hope this is helpful. Thank you.