Reactive Arthritis (ReA)
What is ReA?
Reactive Arthritis is often a distinct type of Spondyloarthritis (SpA; see also Patient Information on ‘Spondyloarthritis’). It means ‘reactive’ to an infection. Only specific infections however trigger a SpA-related Reactive Arthritis (not any). The main ones (we know of) are Campylobacter, Salmonella, Shigella, Yersinia and Chlamydia. The ‘reaction’ occurs a few weeks after the infection as musculoskeletal inflammation. It's true that other infections, such as viruses, Borrelia (Lyme) and beta-hemolytic streptococci for example, can trigger a type of arthritis but in these cases the reactive arthritis is not of the SpA type.
The ‘reaction’ occurs a few weeks after the infection as musculoskeletal inflammation. It's true that other infections, such as viruses, Borrelia (Lyme) and beta-hemolytic streptococci for example, can trigger a type of arthritis but in these cases the reactive arthritis is not of the SpA type.
How is ReA diagnosed?
A typical symptom story interpreted by a Rheumatologist then a musculoskeletal examination and possibly some
imaging - most likely ultrasound of entheses (the ends of ligaments and tendons; see Box 3 in the Patient Information Leaflet of ‘Spondyloarthritis’) or MRI (spine/pelvis) is the best way of making a diagnosis.
The symptoms of ReA?
Symptoms of infection usually precede the pains. Campylobacter and Salmonella infections usually affect the gut (‘enteric’). Shigella too affects the gut but it is a rare infection to get in Western Europe. Yersinia infection frequency is somewhat unknown, but the infection can be mild, and may not even be noticed. The most frequent way Chlamydia causes infection is by sexually transmitted disease (the ReA is sometimes termed Sexually Acquired Reactive Arthritis; SARA). Most men have genital symptoms when they get Chlamydia genital infection but about 50% of women who get the infection have no genital or pelvic symptoms, so establishing the diagnosis in women can be difficult. The most typical musculoskeletal symptoms (the ‘reaction’) after the infection (whether gut origin or sexually-acquired) are pain/stiffness of lower spine or sacroiliac (posterior pelvis) structures, enthesitis or pain from a single (or 2-3) swollen joint (e.g. knee or ankle) or digit (dactylitis)
Who gets Reactive Arthritis?
Anyone can get gut infection or Chlamydia sexually transmitted disease given appropriate exposures! However, it then appears that ReA is more likely to occur in people at risk of SpA through their genetic background (e.g. if HLA B27 positive for example). It’s probable that the majority of people who get these infections don’t get ReA at all.
What does the future hold?
Most people who develop ReA have mild disease. Indeed it’s probable that in many people the disease is so mild and limited that people don’t go to the doctor. Some people may go to the doctor but just have enthesitis or mild pain which goes. Only some people get ReA severe enough to warrant referral to a Rheumatologist. A small minority of these people will develop chronic disease but most people, even if symptoms are severe to begin with, have problems just for a few months at most.
What treatments are there?
As with all musculoskeletal inflammation, non-steroidal anti-inflammatory drugs help. With more severe disease a short course of steroid tablets is occasionally necessary. For those people with more chronic disease then typically a trial period, over 6 months, on Sulfasalazine or Methotrexate (see BSR Patient Information on DMARDS) might be recommended by a Rheumatologist.
What things can I do if I have ReA?
By the time a person gets ReA then it’s too late to do anything about the original infection so antibiotics have no role. If you are a sexually active person and you have a diagnosis of ReA then it’s important to establish with your Rheumatologist whether you have SARA and therefore whether further GenitoUrinary specialist investigations are needed. As with all SpAs exercise is generally good and it’s unlikely you will damage joints by continuing exercise though aggressive movement of inflamed musculoskeletal structures (or manipulation) can make pains worse rather than better.
Also see Patient Information on Spondyloarthritis