How is Reactive Arthritis treated?
Treating reactive arthritis is mostly symptomatic, with high doses of anti-inflammatory drugs or steroids into affected joints.
Testing for and treating any underlying infection is often attempted but in many cases the underlying infection is self limited or can no longer be found. If the inciting infectious agent can be determined it must be treated aggressively with antibiotics.
Symptomatic treatment with high doses of a nonsteroidal anti-inflammatory drug (NSAID) and steroid injections into affected joints can be helpful for patients with reactive arthritis.  NSAIDs can reduce joint inflammation and are commonly used to treat patients with reactive arthritis. Some traditional NSAIDs, such as aspirin and ibuprofen, are available without a prescription, but others that are more effective for reactive arthritis, such as indomethacin and voltaren, must be prescribed by a doctor. Less is known about whether a new class of NSAIDs, called COX-2 inhibitors, is effective for reactive arthritis, but they may reduce the risk of gastrointestinal complications associated with traditional NSAIDs.  For people with severe joint inflammation, injections of corticosteroids directly into the affected joint may reduce inflammation. Doctors usually give these injections only after trying unsuccessfully to control arthritis with NSAIDs. In some cases, short courses of oral steroids, such as methylprednisolone or prednisone, may also be required.
A small percentage of patients with reactive arthritis have severe symptoms that cannot be controlled with any of the above treatments. For these people, medicine that suppresses the immune system, such as sulfasalazine or methotrexate, may be effective. [22, 23, 21] If the symptoms do not respond to these agents a newer group of medications, called biologics, can often be very effective. Biologic agents can be either injectables (such as etanercept or adalimumab) or given intravascularly (such as infliximab or rituximab). These agents can be very immunosuppressive and are very expensive so are not used as first-line treatments.
Topical corticosteroids, which come in a cream or lotion, can be applied directly on the skin lesions associated with reactive arthritis. Topical corticosteroids reduce inflammation and promote healing. 
Antibiotics to eliminate the bacterial infection that triggered the reactive arthritis may be prescribed. The specific antibiotic prescribed depends on the type of bacterial infection present. It is important to follow instructions about how much medicine to take and for how long; otherwise the infection may persist. Typically, an antibiotic is taken for 7 to 10 days or longer.  Currently, however, there is no evidence to suggest that antibiotic treatment is beneficial once reactive arthritis has occurred. 
Exercise, when introduced gradually, may help improve joint function. In particular, strengthening and range-of-motion exercises will maintain or improve joint function. Strengthening exercises builds up the muscles around the joint to better support it. Muscle-tightening exercises that do not move any joints can be done even when a person has inflammation and pain. Range-of-motion exercises improve movement and flexibility and reduce stiffness in the affected joint. For patients with spine pain or inflammation, exercises to stretch and extend the back can be particularly helpful in preventing long-term disability. Aquatic exercise also may be helpful. Before beginning an exercise program, patients should talk to a health professional who can recommend appropriate exercises. 
What Is the Prognosis for People Who Have Reactive Arthritis?
Most people with reactive arthritis recover fully from the initial flare of symptoms and are able to return to regular activities 2 to 6 months after the first symptoms appear. In some cases, the symptoms of arthritis may last up to 12 months, although these symptoms are usually very mild and do not interfere with daily activities. Approximately 20% of people with reactive arthritis will have chronic (long-term) arthritis, which usually is mild.
Studies show that between 15% and 50% of patients will develop symptoms again sometime after the initial flare has disappeared. [15, 21] Back pain and arthritis are the symptoms that most commonly reappear. Up to one-third of affected individuals will have chronic, severe arthritis that is difficult to control with treatment and may cause joint deformity. [13, 24, 21, 15] One study found that two-thirds of individuals who developed reactive arthritis after a Salmonella infection continued to have symptoms at five years of follow-up.  Symptoms were severe enough to force a change in work for four of 18 individuals and another four had objective damage to joints radiographically.
Overall, a relapsing course appears less common in enteric-infection-related disease than in Chlamydia-associated reactive arthritis (of genitourinary origin). HLA-B27 contributes to the development of chronic disease and therefore, the prognosis is less favorable in those who are HLA-positive. [1, 24]