ANKYLOSING SPONDYLITIS

Q. A 22 year old man has had an acute, painful, red right eye with blurring of vision for one day. He had a similar episode one year ago and has had episodic back pain and stiffness relieved by exercise and diclofenac for four years. What is the most likely cause of his red eye?
a) Chorioretinitis
b) Conjunctivitis
c) Episcleritis
d) Iritis
e) Keratitis

Ans: d) Iritis


Explanation: 

Ankylosing spondylitis (AS):  is a chronic inflammatory disease of the spine and sacroiliac joints, of unknown aetiology. 
Prevalence: 0.25–1%. 

 Men present earlier:  M:F≈ 6:1 at 16yrs old, and ~2:1 at 30yrs old. ~90% are HLA B27 +ve 
 
Symptoms and signs: The typical patient is a man <30yrs old with gradual onset of low back pain, worse at night, with spinal morning stiff ness relieved by exercise. Pain radiates from sacroiliac joints to hips/buttocks, and usually improves towards the end of the day. There is progressive loss of spinal movement (all directions)—hence thoracic expansion. . The disease course is variable; a few progress to kyphosis, neck hyperextension, and spino-cranial ankylosis. Other features include enthesitis , especially Achilles tendonitis, plantar fasciitis, at the tibial and ischial tuberosities, and at the iliac crests. Anterior mechanical chest pain due to costochondritis and fatigue may feature. 
 Acute iritis occurs in~⅓ of patients and may lead to blindness if untreated (but may also have occurred many years before, so enquire directly). AS is also associated with osteoporosis (up
to 60%), aortic valve incompetence (<3%) and pulmonary apical fibrosis. 

Tests: Diagnosis is clinical, supported by imaging (MRI is most sensitive and better at detecting early disease). Sacroiliitis is the earliest X-ray feature, but may appear late: look for irregularities, erosions, or sclerosis aff ecting the lower half of the sacroiliac joints, especially the iliac side. Vertebral syndesmophytes are characteristic: bony proliferations due to enthesitis between ligaments and vertebrae. These fuse with the vertebral body above, causing ankylosis. In later stages, calcification of ligaments with ankylosis lead to a ‘bamboo spine’ appearance.
Also: FBC (normocytic anaemia), increased ESR, CRP, HLA B27+ve (not diagnostic).
 
Management:  Exercise, not rest, for backache, including intense exercise regimens to maintain posture and mobility—ideally with a physiotherapist specializing in AS. NSAIDS  usually relieve symptoms within 48h, and they may slow radiographic progression. 41 TNF alfa blockers etanercept, adalimumab and golimumab are indicated in severe active AS if NSAIDS fail . Local
steroid injections provide temporary relief. Surgery includes hip replacement to improve pain and mobility if the hips are involved, and rarely spinal osteotomy. There is increased risk of osteoporotic spinal fractures (consider bisphosphonates). Prognosis: There is not always a clear relationship between the activity of arthritis and severity of underlying infl ammation (as for all the spondyloarthritides). Prognosis is worse if ESR >30; onset <16yrs; early hip involvement or poor response to NSAIDS.