As you have said that you had thyroid cancer
, had thyroidectomy
+ radio iodine
, now complete hypothyroidism
and taking thyroxine
Yes hypothyroidism either medical or surgical does cause increse in allergies , like allergic nose , asthma , food allergies .
Usually people donot complain of severe allergies after thyroid removed , but in some patients there is an aggravation of immunity , as thyroid has a hidden role in immunomodulation.
Hope this helps