Updated: 9/10/2017

Psoriatic Arthritis

Topic
Review Topic
0
0
Questions
1
0
0
Evidence
2
0
0
Snapshot
  • A 32-year-old man presents to his rheumatologist for evaluation of new-onset joint pain. He reports feeling stiffness in his lower back in the morning and in the most distal joints in his left hand. He has a past medical history of psoriasis. On physical exam, he has papules and plaques along his hairline and scalp with overlying silver scales. His left middle finger has dactylitis and the distal interphalangeal joint is swollen. Laboratory evaluation shows that he is seronegative for rheumatoid factor. He is started on apremilast.
Introduction
  • Clinical definition
    • a seronegative spondyloarthritis associated with skin psoriasis
  • Epidemiology
    • incidence
      • < 1% of population
      • 20-30% of patients with psoriasis
    • demographics
      • peak incidence in 30-50 years of age
    • risk factors
      • scalp psoriasis
      • nail lesions in psoriasis
  • Etiology
    • idiopathic
  • Pathogenesis
    • ↑ interferon-α, IL-6, tumor necrosis factor-α, and other inflammatory markers recruit T-cells into skin and joints
    • osteoclasts are exposed to inflammatory molecules in the psoriatic joint, triggering osteoclast activation and causing osteolysis
  • Associated conditions
    • skin psoriasis
    • other HLA-B27 autoimmune diseases
Presentation
  • Symptoms
    • asymmetric joint involvement
      • often distal interphalangeal joint (DIP)
      • spine can be involved
    • joint pain
    • joint stiffness in the morning
  • Physical exam
    • swelling in the affected joints
      • in particular the hands > feet
    • dactylitis
      • inflammation of entire digit causing the finger to look like a sausage
    • psoriatic lesions
      • sharply demarcated pink plaque with silvery scale
      • pitting nails
    • uveitis
    • sacroiliitis
Imaging
  • Radiographs
    • indications
      • to confirm diagnosis
    • recommend views
      • affected joints
    • findings
      • bone proliferation and bone resorption
      • pencil-in-cup deformity of DIP, demonstrating erosive changes
        • this is distinct from rheumatoid arthritis
Studies
  • Labs
    • negative rheumatoid factor
    • positive HLA-B27
Differential
  • Ankylosing spondylitis
  • Rheumatoid arthritis
    • metacarpal phalangeal joint involvement, not DIP
Treatment
  • Conservative
    • weight loss
      • indications
        • for patients who are overweight
        • may reduce disease activity in psoriatic arthritis
  • Medical
    • treatment for skin psoriasis, review here
    • nonsteroidal anti-inflammatory drugs (NSAIDs)
      • indication
        • first-line therapy for mild joint symptoms
    • disease-modifying antirheumatic drugs (DMARDs)
      • indication
        • if patients have > 5 joints involved, radiographic damage, or elevated inflammatory markers
      • drugs
        • methotrexate
        • leflunomide
        • sulfasalazine
        • apremilast
        • tumor necrosis factor-α inhibitors
        • anti-interleukin agents
          • ustekinumab
          • secukinumab
Complications
  • Cardiovascular disease
 

Please rate topic.

Average 5.0 of 1 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 (1)
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

Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
ARTICLES (2)
Topic COMMENTS (4)
Private Note