Etiology + Pathology
- Sterile synovitis after post steptococcus/STI/dysentery infection
- Non-specific urethritis/cervicitis
- 30-50% risk is HLA-B27 + (PAIR)
- Shigella, salmonella, Yersinia, Chlamydia, Ureaplasma
- Maybe caused via molecular mimicry/ T cell repertoire selection
Clinical features
- Arthritis – acute, asymmetrical, lower limb
- Enthesitis
- Sacroilitis/spondylitis
- Sterile conjunctivitis
- Skin lesions –
- circinate balanitis , keratoderma blennorrhagica , nail dystrophy
Diagnosis
- FBC
- XR – periarticular osteoporosis, periostitis (metatarsals/phalanges)
Treatment
- Antibiotics (doxycycline), NSAID, sulfasalazine, methotrexate, anti – TNF
