Ans. d. Decreased chest wall expansion (Ref: Harrison 19/e p2170, 18/e p2775)History of back pain, which is more in the morning and relieved by bathing in warm water is characteristic of spondylo arthropathy, like ankylosing spondylitis. Ankylosing spondylitis leads to extra-parenchymal restrictive lung disease, associated with decreased chest wall expansion."Ankylosing Spondylitis: The initial symptom is usually dull pain, insidious in onset, felt deep in the lower lumbar or gluteal region, accompanied by low-back morning stiffness of up to a few hours 'duration that improves with activity and returns following inactivity. "- Harrison 19/e p2170"Ankylosing Spondylitis: Initially; physical findings mirror the inflammatory process. The most specific findings involve loss of spinal mobility, with limitation of anterior and lateral flexion and extension of the lumbar spine and of chest expansion. Limitation of motion is usually out of proportion to the degree of bony ankylosis, reflecting muscle spasm secondary to pain and inflammation. Pain in the sacroiliac joints may be elicited either with direct pressure or with stress on the joints. In addition, there is commonly tenderness upon palpation at the sites of symptomatic bony tenderness and paraspinous muscle spasm. ''-- Harrison 19/e p2170A. Obstructive lung diseaseB. Restrictive lung disease* Asthma* Bronchiectasis* Bronchiolitis* Cystic fibrosis* COPD (Chronic bronchitis, Emphysema)Mnemonic- "ABCDE"ParenchymalExtra Parenchymal* Sarcoidosis* Pneumoconiosis* Idiopathic pulmonary fibrosis* Drug/Radiation induced interstitial lung disease* Neuromuscular diseases:- Diaphragmatic palsy- Guillain-Barre syndrome- Muscular dystrophy- Cervical spine injury* Chest wall diseases:- Kyphoscoliosis- Obesity- Ankylosing spondylitisAnkylosing Spondylitis/Marie-Strumpell or Bchtrew's diseaseEtiology & Pathogenesis:More than 90% patients of AS are HLA B27 positiveQ.The enthesis. the site of ligament attachment to bone is primary site of pathology in ASQ.Sacroilitis is the earliest manifestation with features of both enthesitis & synovitisQ.Clinical Presentation:Males are affected more frequently than females.Age of onset is 15-25 years (late adolescence & early adulthood )Q.The initial symptom is usually dull pain, insidious in onset, accompanied by low back morning stiffness of up to few hours duration that improves with activity and returns following period of inactivityQ.Arthritis in hips & shoulders (root joints) occur in 25-35%Q.Peripheral joints (usually shoulder, hips & knees) are involved in one third of patientsQ.Most serious complication of spinal disease is spinal fracture with even minor trauma.MC extra-articular manifestation is acute anterior uveitis (iridocyclitis)Q.Diagnosis:Radiological Examination(The following changes may be seen on an X-ray of the pelvis)* Haziness of sacro-iliac jointsQ* Irregular subchondral erosions in SI jointsQ* Sclerosis of the articulating surfaces of SI jointsQ* Widening of sacro-iliac joint spaceQ* Bony ankylosis of the sacro-iliac jointsQ* Calcification of the sacro-iliac ligaments and sacro- tuberous ligaments* Evidence of enthesopathy: Calcification at the attachment of the muscles, tendons and ligaments, particularly around the pelvis & heelQ.X-ray of Lumbar spine in Ankylosing Spondylitis* Squaring of vertebraQ: The normal anterior concavity of the vertebral body is lost because of calcification of the anterior tongitudinai ligament* Loss of lumbar lordosisQ* Bridging osteophytes (syndesmophytes)Q* Bamboo spine appearanceQ due to syndesmophytes & paravertebral ossificationTreatment:Phenylbutazone is the most effective drugQ (causes aplastic anemia).Indomethacin is most commonly used NSAIDQ.