MRCP revision battle 6.1: ankylosing spondylitis

Today's revision threw up a mixed bag of topics... a splash of rheumatology with a dash of respiratory and a hint of ophthalmology.

So...

Battle 6.1: ankylosing spondylitis
Battle 6.2: acute iritis
Battle 6.3: Reiters syndrome
Battle 6.4: pleural effusion
Battle 6.5 yellow nail syndrome

Lets get started!


6.1: Ankylosing spondylitis


Ankylosing spondylitis (AS) is a chronic inflammatory disease of the spine and sacroiliac joints.


It affects males more than females, intially around 6:1 but altering to around 2:1 by the age of 30.

 95% of patients are + for HLA B27


Patients often present with low back pain which is worse at night and improves on moving.

Clinically, the things to observe on regarding a patient with AS are:

• a loss of lumbar lordosis
• a fixed kyphosis which is compensated by extension of the cervical spine leading to the classical 
• 'question mark' posture
• if the patient turns their head to the side, the whole body may turn
• there may be decreased chest expansion forcing increased diaphragmatic excursion and hence a
• prominent abdomen

A possible test to undertake is Schobers test - find L5 (roughly level with the sacral dimples) then mark a level 5cm below and 10cm above.  Get the patient to bend over; this 15cm distance should increase to at least 20cm, if it doesn't is suggests AS.

Associations of AS include:

• iritis
• aortic regurgitation
• fibrosis (rare)
• cardiac conduction abnormalities (around 10%, mostly long PR)
• secondary amyloidosis

Management is keeping mobile, NSAIDs and in severe cases tumour necrosis factor alpha blockers such as infliximab.

As an aside, if considering a TNF alpha blocker its a good idea to check TB status as it is likely to reactivate latent TB.


Onwards.... 6.2!