hypothyroid and continuous temperature (upto 100F) and joint pain

My Mrs. gave birth to my daughter in 2006. Afterwards she diagnosed with hypothyroidism and started thyroxine. After some time she started feeling pain in her joints. The doctor asked for the ACTH level. It was low then the Doctor suggested for the Brain MRI which was also normal. Insulin tolerance test was also conducted which ensured for the less ACTH level. One of the doctors started steroids. She took steroids for 3 year and at the last stopped taking steroids by gradually decreasing the dose. Now she is feeling temperature from 99F to 100F and also joint pains. She takes paracetamole tablets daily. She has completed vitamin D courses multiple time. I have tried multiple doctors but unable to be diagnosed. Please help