There are 2 choices, die off or an immune reaction, I would lean towards the immune reaction. With any infection, the immune system becomes dysregulated which means that there are reactions to things you did not have before. The immune system is quite powerful and affects many things.
You can also check the LIV3 acupuncture point which you can find diagrams online. Press your thumb into that point and see if it hurts, if it does hurt then a good chance your liver is congested. With liver congestion you become more sensitive to toxins since they are not being eliminated then the immune system becomes overly activated since there is a direct connection between toxins and immunity.
Detoxification becomes a needed issue with chronic infections.