Hello!
Reactive arthritis is a chronic form of arthritis featuring the following three conditions: (1) inflamed joints, (2) infection of the eyes (conjunctivitis), and (3) inflammation of the genital or urinary organs.
Reactive arthritis is an autoimmune Rheumatoid factor negative and spine involvement with HLA B27 tissue type positive in up to 95% of the cases. It is usually precipitated 1 to 3 weeks after some GI tract or Urinary tract infection. Though HLA B27 is negative in your case, the constellation of symptoms ranging from Prostatitis, tendonitis and other chest and back symptoms could be the reason for suspecting Reactive arthritis.
Blood tests like ESR may be obtained to document the presence of inflammation in the body. Similarly, urinalysis and culture of the urine may be necessary to detect bacterial infection in the urinary tract.
Immunosuppressive drugs given for the treatment of Reactive Arthritis could be the reason for an opportunistic infection by EBV in an already immunocompromised state resulting in high grade fever for 7 days. Antibiotics, Methotrexate and Steroids are also known to cause GI symptoms as their common most side effects. Hence, doses are needed to be titrated with respect to the possible side effects and benefits by the treating physician. Though the disease is known to recur with varying severity of symptoms yet most people can expect to live normal life spans and maintain a near-normal lifestyle with appropriate medication and care. Proper follow up is required so you have to be in regular contact with your physician (gastroenterologist, Rheumatologist) and be informed about the disease. You can also seek consultation at a clinic/hospital equipped with multi disciplinary treatment approach.
Take care