Ankylosing spondylitis and reactive arthritis

Both belong to the spondyloarthritis family and can cause back pain, stiffness, swollen joints, tendon-attachment pain, or eye inflammation. A clinician uses the timing, distribution of symptoms, recent infections, examination, blood tests, and imaging to distinguish them; no single symptom settles the diagnosis.

Ankylosing spondylitis, also called radiographic axial spondyloarthritis, mainly affects the sacroiliac joints and spine. It often presents with inflammatory back stiffness that is worse after rest and eases with movement. Reactive arthritis begins after an infection, commonly involving the bowel or urinary tract, even when the infection itself has already settled.

Reactive arthritis may affect the knees, ankles, feet, skin, eyes, or urinary tract. Some people have features that overlap, and an earlier label may change as the pattern becomes clearer. A history of infection supports reactive arthritis but does not confirm it by itself.

Arrange a medical review for persistent inflammatory back pain, new joint swelling, heel pain, or symptoms that followed diarrhoea or urinary discomfort. Note when each symptom began and whether movement or rest changes it. Mention recent infections, eye redness, skin changes, and any family history of spondyloarthritis.

Treatment is matched to the active problem. It may include anti-inflammatory medication when suitable, treatment of any ongoing infection, and guided exercise to preserve mobility and strength. Do not start leftover antibiotics: antibiotics do not treat joint inflammation when the triggering infection has cleared.

Seek same-day medical assessment for a painful red eye, light sensitivity, or blurred vision because eye inflammation needs prompt examination. A hot, markedly swollen joint with fever also needs urgent assessment to exclude a joint infection.

Go to emergency care for new leg weakness, numbness around the groin, loss of bladder or bowel control, severe chest pain, or difficulty breathing. These warning signs require assessment regardless of whether ankylosing spondylitis or reactive arthritis is suspected.

Ask which features point toward axial inflammation and which suggest an infection-related episode. Useful follow-up questions include whether the sacroiliac joints need imaging, whether current medicines are safe with your other conditions, and which movements are appropriate while a joint is swollen.