Updated: 7/10/2019

Ankylosing Spondylitis

Topic
Review Topic
0
0
Questions
8
0
0
Evidence
2
0
0
Snapshot
  • A 21-year-old man presents with severe morning back pain over the past three months. His pain improves as the day progreses and with excercise. Physical exam shows a stooped posture and diminished anterior flexion of the lumbar spine. Radiography of the lumbar spine shows bilateral sclerotic changes in the sacroiliac area. Laboratory testing shows that the patient is HLA-B27 positive.
Introduction
  • Clinical definition
    • chronic inflammatory disorder that primarily affects the sacroiliac joint and spine
  • Epidemiology
    • demographics
      • more common in men
      • peak onset age is 15-35 years of age
    • risk factors
      • HLA-B27 gene presence  
        • seen with PAIR (Psoriasis, Ankylosing spondylitis, Inflammatory bowel disease, Reactive arthritis)
  • Etiology
    • unknown but may involve both genetic (e.g., HLA B-27 positivity) and environmental factors
  • Pathogenesis
    • unclear but involves inflammation, bone erosion, and spur formation
      • can result in spinal fusion and costovertebral and costosternal
        ankylosis
    • involves the entheses
      • connective tissue between bone and a tendon or ligament
  • Associated conditions
    • psoriasis
    • inflammatory bowel disease
    • anterior uveitis
    • aortic regurgitation
  • Prognosis
    • may lead to chronic pain and stiffness
Presentation
  • Symptoms
    • back pain
      • worse in the morning and lasts approximately 30 minutes
      • improves with activity
    • stiffness of the spine
    • with anterior uveitis
      • photophobia
      • watering and redness of the eye
  • Physical exam
    • may have stooped posture
    • positive Schober test
      • demonstrates limited spine flexibility
    • decreased chest wall expansion
Presentation
  • Radiography 
    • indication
      • gold standard for evaluating and supporting the diagnosis of ankylosing spondylitis
    • findings
      • "bamboo spine" 
      • sacroiliac joint  
        • best initial test
Studies
  • Labs
    • HLA-B27 positivity
      • seen in > 90% of patients
Differential
  • Mechanical low back pain
  • Enteropathic arthritis
  • Reactive arthritis
  • Psoriatic arthritis
Treatment
  • Conservative
    • patient education and exercise
      • indication
        • mainstay of treatment
  • Medical
    • nonsteroidal antiinflammatory drugs (NSAIDs)
      • indication
        • considered first-line treatment for managing pain and stiffness
    • tumor necrosis factor (TNF) inhibitors
      • indication
        • typically used in patients who do not respond to conservative and NSAID treatment
      • medications
        • adalimumab
        • etanercept
Complications
  • Low bone density due to inflammation and osteoporosis/osteopenia 
    • can predispose the patient to vertebral fractures 
  • Spine fracture leading to injury of the spinal cord
  • Restrictive lung disease
 

Please rate topic.

Average 4.1 of 10 Ratings

Thank you for rating! Please vote below and help us build the most advanced adaptive learning platform in medicine

The complexity of this topic is appropriate for?
How important is this topic for board examinations?
How important is this topic for clinical practice?
Questions (8)
Lab Values
Blood, Plasma, Serum Reference Range
ALT 8-20 U/L
Amylase, serum 25-125 U/L
AST 8-20 U/L
Bilirubin, serum (adult) Total // Direct 0.1-1.0 mg/dL // 0.0-0.3 mg/dL
Calcium, serum (Ca2+) 8.4-10.2 mg/dL
Cholesterol, serum Rec: < 200 mg/dL
Cortisol, serum 0800 h: 5-23 μg/dL //1600 h:
3-15 μg/dL
2000 h: ≤ 50% of 0800 h
Creatine kinase, serum Male: 25-90 U/L
Female: 10-70 U/L
Creatinine, serum 0.6-1.2 mg/dL
Electrolytes, serum  
Sodium (Na+) 136-145 mEq/L
Chloride (Cl-) 95-105 mEq/L
Potassium (K+) 3.5-5.0 mEq/L
Bicarbonate (HCO3-) 22-28 mEq/L
Magnesium (Mg2+) 1.5-2.0 mEq/L
Estriol, total, serum (in pregnancy)  
24-28 wks // 32-36 wks 30-170 ng/mL // 60-280 ng/mL
28-32 wk // 36-40 wks 40-220 ng/mL // 80-350 ng/mL
Ferritin, serum Male: 15-200 ng/mL
Female: 12-150 ng/mL
Follicle-stimulating hormone, serum/plasma Male: 4-25 mIU/mL
Female: premenopause: 4-30 mIU/mL
midcycle peak: 10-90 mIU/mL
postmenopause: 40-250
pH 7.35-7.45
PCO2 33-45 mmHg
PO2 75-105 mmHg
Glucose, serum Fasting: 70-110 mg/dL
2-h postprandial:<120 mg/dL
Growth hormone - arginine stimulation Fasting: <5 ng/mL
Provocative stimuli: > 7ng/mL
Immunoglobulins, serum  
IgA 76-390 mg/dL
IgE 0-380 IU/mL
IgG 650-1500 mg/dL
IgM 40-345 mg/dL
Iron 50-170 μg/dL
Lactate dehydrogenase, serum 45-90 U/L
Luteinizing hormone, serum/plasma Male: 6-23 mIU/mL
Female: follicular phase: 5-30 mIU/mL
midcycle: 75-150 mIU/mL
postmenopause 30-200 mIU/mL
Osmolality, serum 275-295 mOsmol/kd H2O
Parathyroid hormone, serume, N-terminal 230-630 pg/mL
Phosphatase (alkaline), serum (p-NPP at 30° C) 20-70 U/L
Phosphorus (inorganic), serum 3.0-4.5 mg/dL
Prolactin, serum (hPRL) < 20 ng/mL
Proteins, serum  
Total (recumbent) 6.0-7.8 g/dL
Albumin 3.5-5.5 g/dL
Globulin 2.3-3.5 g/dL
Thyroid-stimulating hormone, serum or plasma .5-5.0 μU/mL
Thyroidal iodine (123I) uptake 8%-30% of administered dose/24h
Thyroxine (T4), serum 5-12 μg/dL
Triglycerides, serum 35-160 mg/dL
Triiodothyronine (T3), serum (RIA) 115-190 ng/dL
Triiodothyronine (T3) resin uptake 25%-35%
Urea nitrogen, serum 7-18 mg/dL
Uric acid, serum 3.0-8.2 mg/dL
Hematologic Reference Range
Bleeding time 2-7 minutes
Erythrocyte count Male: 4.3-5.9 million/mm3
Female: 3.5-5.5 million mm3
Erythrocyte sedimentation rate (Westergren) Male: 0-15 mm/h
Female: 0-20 mm/h
Hematocrit Male: 41%-53%
Female: 36%-46%
Hemoglobin A1c ≤ 6 %
Hemoglobin, blood Male: 13.5-17.5 g/dL
Female: 12.0-16.0 g/dL
Hemoglobin, plasma 1-4 mg/dL
Leukocyte count and differential  
Leukocyte count 4,500-11,000/mm3
Segmented neutrophils 54%-62%
Bands 3%-5%
Eosinophils 1%-3%
Basophils 0%-0.75%
Lymphocytes 25%-33%
Monocytes 3%-7%
Mean corpuscular hemoglobin 25.4-34.6 pg/cell
Mean corpuscular hemoglobin concentration 31%-36% Hb/cell
Mean corpuscular volume 80-100 μm3
Partial thromboplastin time (activated) 25-40 seconds
Platelet count 150,000-400,000/mm3
Prothrombin time 11-15 seconds
Reticulocyte count 0.5%-1.5% of red cells
Thrombin time < 2 seconds deviation from control
Volume  
Plasma Male: 25-43 mL/kg
Female: 28-45 mL/kg
Red cell Male: 20-36 mL/kg
Female: 19-31 mL/kg
Cerebrospinal Fluid Reference Range
Cell count 0-5/mm3
Chloride 118-132 mEq/L
Gamma globulin 3%-12% total proteins
Glucose 40-70 mg/dL
Pressure 70-180 mm H2O
Proteins, total < 40 mg/dL
Sweat Reference Range
Chloride 0-35 mmol/L
Urine  
Calcium 100-300 mg/24 h
Chloride Varies with intake
Creatinine clearance Male: 97-137 mL/min
Female: 88-128 mL/min
Estriol, total (in pregnancy)  
30 wks 6-18 mg/24 h
35 wks 9-28 mg/24 h
40 wks 13-42 mg/24 h
17-Hydroxycorticosteroids Male: 3.0-10.0 mg/24 h
Female: 2.0-8.0 mg/24 h
17-Ketosteroids, total Male: 8-20 mg/24 h
Female: 6-15 mg/24 h
Osmolality 50-1400 mOsmol/kg H2O
Oxalate 8-40 μg/mL
Potassium Varies with diet
Proteins, total < 150 mg/24 h
Sodium Varies with diet
Uric acid Varies with diet
Body Mass Index (BMI) Adult: 19-25 kg/m2
Calculator

(M3.RH.60) A 23-year-old man complains of lower back pain that began approximately 6 months ago. He is unsure why he is experiencing this pain and notices that this pain is worse in the morning after waking up and improves with physical activity. Ibuprofen provides significant relief. He denies bowel and bladder incontinence or erectile dysfunction. Physical exam is notable for decreased chest expansion, decreased spinal range of motion, 5/5 strength in both lower extremities, 2+ patellar reflexes bilaterally, and an absence of saddle anesthesia. Which of the following is the most appropriate next test for this patient? Review Topic

QID: 103001
1

ESR

0%

(0/0)

2

HLA-B27

0%

(0/0)

3

MRI sacroiliac joint

0%

(0/0)

4

Radiograph sacroiliac joint

0%

(0/0)

5

Slit-lamp examination

0%

(0/0)

M2

Select Answer to see Preferred Response

PREFERRED RESPONSE 4
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK

(M2.RH.4867) A 27-year-old man presents to the emergency department with back pain. The patient states that he has back pain that has been steadily worsening over the past month. He states that his pain is worse in the morning but feels better after he finishes at work for the day. He rates his current pain as a 7/10 and says that he feels short of breath. His temperature is 99.5°F (37.5°C), blood pressure is 130/85 mmHg, pulse is 80/min, respirations are 14/min, and oxygen saturation is 99% on room air. On physical exam, you note a young man who does not appear to be in any distress. Cardiac exam is within normal limits. Pulmonary exam is notable only for a minor decrease in air movement bilaterally at the lung bases. Musculoskeletal exam reveals a decrease in mobility of the back in all four directions. Which of the following is the best initial step in management of this patient? Review Topic

QID: 109539
1

Pulmonary function tests

5%

(2/37)

2

Radiography of the lumbosacral spine

76%

(28/37)

3

MRI of the sacroiliac joint

19%

(7/37)

4

CT scan of the chest

0%

(0/37)

5

Ultrasound

0%

(0/37)

M2

Select Answer to see Preferred Response

PREFERRED RESPONSE 2

(M2.RH.4662) A 27-year-old male presents to his primary care physician with lower back pain. He notes that the pain started over a year ago but has become significantly worse over the past few months. The pain is most severe in the mornings. His past medical history is unremarkable except for a recent episode of right eye pain and blurry vision. Radiographs of the spine and pelvis show bilateral sacroiliitis. Which of the following is the most appropriate treatment for this patient? Review Topic

QID: 107052
1

Indomethacin

58%

(19/33)

2

Methotrexate

9%

(3/33)

3

Cyclophosphamide

0%

(0/33)

4

Oral prednisone

27%

(9/33)

5

Bed rest

0%

(0/33)

M2

Select Answer to see Preferred Response

PREFERRED RESPONSE 1
ARTICLES (2)
Topic COMMENTS (6)
Private Note