I am currently not receiving any medication for my condition, but I am plagued with chronic sinusitis. However, I am now told that my septum has once again becomed deviated. I'm not aware of thyroid disease being one of them. In general, the sinuses drain from very small holes and any blockage or difficulty draining sets one up for chronic sinus infections. Like most parts of the body, the lack of drainage gives bacteria and fungal agents a perfect growing environment.
Fungal infections are an uncommon cause of fungal problems.
They typically occur in diabetics and in people with impaired immunity. Treatment is usually medical, and not surgical, although removal of large fungal masses is sometimes necessary. Use of normal antibiotics is completely ineffective against most fungal agents, with Nocardia being the exception. If you really have a fungal infection of the sinuses, I would consult an Internist or Infectious Disease Specialist. The problem only seems to be getting stranger.