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Health Dictionary

Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.

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Psoriatic arthritis differential diagnosis

Introduction

Overview

Overview

Psoriatic arthritis must be differentiated from other arthritides including rheumatoid arthritis, reactive arthritis, ankylosing spondylitis, arthritis associated with inflammatory bowel disease, osteoarthritis, gout, and Pseudogout.

Differentiating psoriatic arthritis from other Diseases

Differentiating psoriatic arthritis from other Diseases

Differential Diagnosis of Diseases That Cause Polyarthritis

Diseases Clinical manifestations Para-clinical findings Gold standard Additional findings
Symptoms Physical examination
Lab Findings Imaging Histopathology
Joint Swelling Fever Weight loss Claudication Morning stiffness Local erythema Skin manifestation CBC ESR Synovial fluid Other X-ray CT scan Other
Polyarthritis Infectious arthritis Lyme disease[5] + + +/- +/- – – Erythema migrans Leukopenia, Thrombocytopenia – Cell counts 500-98,000/µL Microscopic hematuria, Proteinuria, ↑ALT or AST – – – Fibrosis of the deeper dermis and hyalinization of collagen bundles Serologic tests Erythema migrans
Bacterial endocarditis[6] + + + – – +/- Janeway lesions, Osler nodes, Roth spots Normochromic-normocytic anemia ↑ ↑WBC, S. aureus in culture Hyperglobulinemia, Cryoglobulinemia Joint erosion and effusion – – Vegetation or intracardiac abscess demonstrating active endocarditis Echocardiography (TTE) Vertebral osteomyelitis
Postinfectious (reactive) arthritis Rheumatic fever[7] + + – – – +/- Erythema marginatum rheumaticum Leukocytosis ↑ Sterile inflammatory reaction with cells<20,000/μL Streptococcal antibody titer Cardiomegaly Valvular or pericardial calcification Echocardiographic changes in heart valves Edema, Fibrinoid necrosis, Mononuclear cell infiltrate Echocardiography Chorea, Carditis 
Reactive arthritis[8] +/- +/- – – – – Genital ulceration Normocytic normochromic anemia ↑  High WBC count (10,000-40,000/µL)  HLA-B27 test  Periosteal reaction and proliferation of tendon insertion site Sacroiliitis Enthesitis in ultrasonography Keratoderma blennorrhagicum, Balanitis circinata   Spondyloarthritis and unequivocal demonstration of preceding infection Conjunctivitis, Uveitis
Enteric infection[9] – + – – – – Keratoderma and psoriaform lesions, Erythema nodosum Neutrophilia ↑ PCR of causative organism Stool exam and culture – – – Neutrophilic infiltration in synovial tissues PCR of causative organism in synovial fluid Diarrhea, Enthesopathy
Other seronegative spondyloarthritides Ankylosing spondylitis[10] + – +/- +/- + – Dactylitis (sausage digit) Normocytic normochromic anemia ↑  High WBC count (lymphocyte predominance) ↑Alkaline phosphatase (ALP) Bony erosions and sclerosis of the joints  Early sacroiliitis, erosions, and enthesitis Possible cauda equina syndrome secondary to spinal stenosis in MRI Chronic inflammation with CD4+ and CD8+ T lymphocytes and macrophages Plain x-rays Peripheral enthesitis, Uveitis 
Psoriatic arthritis[11] + – – – – + Scaly erythematous plaques,

Guttate lesions, Lakes of pus,

Erythroderma

Normal ↑ High WBC count (5000-15,000/µL) with >50% of PMN leukocytes ↑RF, ANA, IgA Joint-space narrowing, Fluffy periostitis Pencil-in-cup deformity, Early signs of synovitis Sacroiliitic synovitis, Enthesitis in MRI Lack of intrasynovial Ig and RF, Greater propensity for fibrous ankylosis, osseous resorption, and heterotopic bone formation Clinical findings Onycholysis, Splinter hemorrhages
Inflammatory bowel disease[12] + + – – + +/- Pyoderma gangrenosum (ulcerative colitis), Erythema nodosum (Crohn disease) Iron deficiency anemia, Leukocytosis, Thrombocytosis ↑ Mild to moderate inflammatory fluid, PMN predominance ↑RF, Antiendomysial Ab, Antitransglutaminase Ab Bilateral sacroiliitis, Syndesmophytes and apophyseal joint involvement in spine – Early detection of spinal and sacroiliac lesions in MRI – Clinical findings and history Acute anterior uveitis
Rheumatoid arthritis[13] + – + + + – Rheumatoid nodules Anemia, Thrombocytosis ↑ WBC count >2000/µL (generally 5000-50,000/µL), with neutrophil predominance (60-80%) Anti-CCP Ab, Hyperuricemia Joint-space narrowing Microfractures Synovitis in MRI Influx of inflammatory cells into the synovial membrane, with angiogenesis Clinical findings coupled anti-CCP antibody Rheumatoid nodules
Crystal-induced arthritis[14] + +/- – – – + Joint erythema Leukocytosis ↑ Needle shaped urate crystals, WBC count > 2000/µL Urinary uric acid (>1100 mg in 24h) Punched-out erosions or lytic areas with overhanging edges  Complementary for recognizing erosions Tophi or edema in MRI Large pale pink acellular areas (urate crystals), surrounded by histiocytes and multinucleated giant cells Synovial fluid assay Conjunctival nodules
Systemic rheumatic illnesses Systemic lupus erythematosus[15] + – +/- – – + Malar rash, Photosensitivity, Discoid lupus Leukopenia, Lymphopenia, Anemia, Thrombocytopenia ↑ Cell count from < 25% PMNs (non-inflammatory effusions) to > 50% PMNs (inflammatory effusions) Creatine kinase, LFT, ANA, Anti-dsDNA, Anti-Sm, Lupus anticoagulant Periarticular osteopenia and soft-tissue swelling without erosions Interstitial lung disease, Pneumonitis, Pulmonary emboli, Alveolar hemorrhage Pericardial effusion, Pulmonary hypertension, Verrucous Libman-Sacks endocarditis in echocardiography Inflammatory infiltrates at the dermoepidermal junction and vacuolar change in the basal columnar cells Anti-dsDNA Rheumatoid arthritis, Serositis, Oral ulcers
Systemic vasculitis[16] – – +/- + – – Petechia, Purpura Anemia, Thrombocytosis ↑ – P-ANCA, C-ANCA, ANA Soft tissue swelling with mild erosions Focal regions of infarction or hemorrhage Multiple microaneurysms,Hemorrhage due to focal rupture, Occlusion in angiography Acute destruction of the media by neutrophils, with loss of elastic fibers Angiography Peripheral neuropathy, Livedo reticularis
Systemic sclerosis[17] – – +/- – – – 3 phases of (1) Edematous, (2) Indurative, and (3) Atrophic Thrombocytopenia ↑ Cell count < 25% PMNs (non-inflammatory) Hypergammaglobulinemia,

Creatine phosphokinase

Juxta-articular osteoporosis, Joint space narrowing, Frank erosions Synovial inflammation Synovial vascularity in doppler ultrasonography Epidermal skin appendages atrophy, Broad and hyalinized collagen fibers in the reticular dermis Histopathology Raynaud phenomenon, Tendon friction rubs
Polymyositis/dermatomyositis[18] – – +/- – – + Heliotrope rash, Gottron papules, Poikiloderma Normocytic normochromic anemia ↑ Predominantly mononuclear cells and large macrophage-like cells Anti–Mi-2 antibodies, Anti–Jo-1 antibodies, Creatine kinase, ANA Marginal erosions and periarticular calcification – – Vacuolar changes of the columnar epithelium and lymphocytic infiltrates Muscle biopsy Dysphagia 
Still’s disease[19] – – +/- – +/- + Mild papules and nodules Anemia, Thrombocytosis ↑ High WBC count (5000-15,000/µL) with >50% of PMN leukocytes ANA, RF Soft tissue swelling,

Osteopenia,

Joint-space narrowing

Synovial inflammation Inflamed synovium in ultrasonography Inflammatory infiltration in synovium Clinical findings and synovial fluid analysis Ocular involvement
Behçet’s syndrome[20] + – – – – – Erythema nodosum Normocytic normochromic anemia ↑ Cell count < 25% PMNs (non-inflammatory) Serum complement levels, Human leukocyte antigen (HLA)-B51 Soft tissue swelling Non-erosive synovitis – Dermal vessels infiltration with lymphocytes and plasma cells, Immune deposits of immunoglobulin M (IgM) and C3 Clinical findings Oral ulcer, Mucosal erosion
Relapsing polychondritis[21] + – – – – – – Leukocytosis, Anemia – Cell count < 25% PMNs (non-inflammatory) Cryoglobulins, ANA, C-ANCA Tracheal stenosis in CXR Calcification of cartilaginous structures Aortic root dilatation and degree of aortic regurgitation in echocardiography Chondrolysis, Chondritis, Perichondritis Clinical findings coupled with imaging Ear pain and redness, Polyarthritis
Other systemic illnesses Sarcoidosis[22] + – – – – – Mild papules and nodules Mild anemia ↑ Cell count < 25% PMNs (non-inflammatory)  IL-2 and IFN-γ, ↑ACE, ↑1, 25-dihydroxyvitamin D Bilateral hilar adenopathy Active alveolitis or fibrosis Hepatosplenomegaly in ultrasonography Noncaseating granulomas (NCGs) Histological confirmation Heart block, Ocular lesion
Palindromic rheumatism[23] + – – +/- + – Rheumatoid nodules Anemia ↑ High WBC count (5000-15,000/µL) with >50% of PMN leukocytes RF, Anti-CCP antibody, ↑Cr or BUN,

↑ALT or AST, ANA

Effusions in joints Microfractures Basilar invagination with cranial migration of an eroded odontoid peg in MRI Influx of inflammatory cells into the synovial membrane, withangiogenesis, proliferation of chronic inflammatory cells Clinical findings coupled anti-CCP antibody Rheumatoid nodules
Familial Mediterranean fever[24] – + – – – – A well-demarcated, erythematous, warm rash, particularly below the knee Leukocytosis ↑ Cell counts as high as 100,000/µL CRP, Amyloid A protein, Fibrinogen Synovial effusions Pleural effusions Air-fluid levels in MRI Massive amyloid infiltration of the blood vessels and endothelial side of the glomerular basement membrane Clinical findings Abdominal pain, Severe myalgia, Scrotal attacks
Hyperlipoproteinemias[25] – – – – – – Xanthelasma Leukocytosis ↑ Xanthochromic fluid with mononuclear cells predominance CRP, Hyperlipidemia Joint space narrowing Achilles tendon enthesitis Retrocalcaneal bursitis and ill-defined edema in posterosuperior corner of the calcaneus Inflammatory infiltration Laboratory findings Atherosclerosis
Polyarticular pain Viral arthritis Hepatitis B and C[26] – + + – – – Urticarial and maculopapular eruptions  Leukocytosis ↑ Cell counts < 100,000/µL LFT, HBsAg Joint space narrowing – – Deposition of immune complexes, Cryoprecipitates containing HBsAg and complements HBsAg Liver failure, Icterus
Rubella[27] – + +/- – – – Acute maculopapular rash Leukocytosis ↑ Rubella virus antigen LFT, CRP Joint space narrowing – – proliferation of the synovial lining cells, without inflammatory

cells

Serological evidence Headache, Malaise
Parvovirus[28] + + +/- – – – Fifth disease/ Erythema infectiosum Aplastic crisis ↑ Normal ANA, RF, CRP Joint swelling – – Immune complex deposition Parvovirus IgM antibody Transient aplastic crisis, Fetal infection
Fibromyalgia[29] – – – +/- +/- – Maculopapular rash Normal – Normal – – – – Mild inflammation Clinical findings Muscle pain
Soft tissue abnormalities + – – – – +/- Maculopapular rash Normal – Cell count < 25% PMNs (non-inflammatory) CRP, Ca Joint swelling Synovial edema and thickness Mild joint effusion in ultrasonography Mild inflammation Clinical findings Mucositis, Enthesitis
Hypothyroidism[30] – – – – – – Dry and coarse skin Anemia – Clear yellow fluid with normal cell counts TSH, T4, T3 Peri-articular demineralization Destructive changes in the cartilage and bone High-signal fluid in the joint space in MRI Physeal growth plate with little evidence of cartilage cellular proliferation TSH, T4, T3 Decreased DTR, Fatigue
Neuropathic pain[31] – – – – – – Livedo reticularis Normal – Normal Hyperglycemia, Hypokalemia, Hypocalcemia – – – – Neurologic examination Paresthesia, Dysesthesia
Metabolic bone disease[32] – – – – – – Hyperpigmentation Mild anemia ↑ Cell count < 25% PMNs (non-inflammatory) Vitamin D, PTH Peri-articular demineralization Microfractures Subperiosteal reaction Decrease mineralization of bone matrix Laboratory findings Bone pain, Constipation
Depression[33] – – + – – – – Normal – Normal Normal – – – – Psychological interview Slow psychomotor, Muscle pain
References

References

  1. ↑ Helliwell PS, Taylor WJ (March 2005). “Classification and diagnostic criteria for psoriatic arthritis”. Ann. Rheum. Dis. 64 Suppl 2: ii3–8. doi:10.1136/ard.2004.032318. PMC 1766878. PMID 15708931.
  2. ↑ McEwen C, DiTata D, Lingg C, Porini A, Good A, Rankin T (1971). “Ankylosing spondylitis and spondylitis accompanying ulcerative colitis, regional enteritis, psoriasis and Reiter’s disease. A comparative study”. Arthritis Rheum. 14 (3): 291–318. PMID 5562018.
  3. ↑ Helliwell PS, Hickling P, Wright V (March 1998). “Do the radiological changes of classic ankylosing spondylitis differ from the changes found in the spondylitis associated with inflammatory bowel disease, psoriasis, and reactive arthritis?”. Ann. Rheum. Dis. 57 (3): 135–40. PMC 1752543. PMID 9640127.
  4. ↑ Moll JM, Haslock I, Macrae IF, Wright V (September 1974). “Associations between ankylosing spondylitis, psoriatic arthritis, Reiter’s disease, the intestinal arthropathies, and Behcet’s syndrome”. Medicine (Baltimore). 53 (5): 343–64. PMID 4604133.
  5. ↑ Lantos PM (2015). “Chronic Lyme disease”. Infect Dis Clin North Am. 29 (2): 325–40. doi:10.1016/j.idc.2015.02.006. PMC 4477530. PMID 25999227.
  6. ↑ Soor P, Sharma N, Rao C (2017). “Multifocal Septic Arthritis Secondary to Infective Endocarditis: A Rare Case Report”. J Orthop Case Rep. 7 (1): 65–68. doi:10.13107/jocr.2250-0685.692. PMC 5458702. PMID 28630844.
  7. ↑ Kumar RK, Tandon R (2013). “Rheumatic fever & rheumatic heart disease: the last 50 years”. Indian J Med Res. 137 (4): 643–58. PMC 3724245. PMID 23703332.
  8. ↑ Colmegna I, Cuchacovich R, Espinoza LR (2004). “HLA-B27-associated reactive arthritis: pathogenetic and clinical considerations”. Clin Microbiol Rev. 17 (2): 348–69. PMC 387405. PMID 15084505.
  9. ↑ Hill Gaston, J (2003). “Arthritis associated with enteric infection”. Best Practice & Research Clinical Rheumatology. 17 (2): 219–239. doi:10.1016/S1521-6942(02)00104-3. ISSN 1521-6942.
  10. ↑ McVeigh CM, Cairns AP (2006). “Diagnosis and management of ankylosing spondylitis”. BMJ. 333 (7568): 581–5. doi:10.1136/bmj.38954.689583.DE. PMC 1570004. PMID 16974012.
  11. ↑ Sankowski AJ, Lebkowska UM, CwikÅ‚a J, Walecka I, Walecki J (2013). “Psoriatic arthritis”. Pol J Radiol. 78 (1): 7–17. doi:10.12659/PJR.883763. PMC 3596149. PMID 23493653.
  12. ↑ Orchard TR (2012). “Management of arthritis in patients with inflammatory bowel disease”. Gastroenterol Hepatol (N Y). 8 (5): 327–9. PMC 3424429. PMID 22933865.
  13. ↑ Heidari B (2011). “Rheumatoid Arthritis: Early diagnosis and treatment outcomes”. Caspian J Intern Med. 2 (1): 161–70. PMC 3766928. PMID 24024009.
  14. ↑ Reginato A, Paul H, Schumacher HR (September 1982). “Crystal-induced arthritis”. Arch Phys Med Rehabil. 63 (9): 401–8. PMID 6287963.
  15. ↑ Manson JJ, Rahman A (2006). “Systemic lupus erythematosus”. Orphanet J Rare Dis. 1: 6. doi:10.1186/1750-1172-1-6. PMC 1459118. PMID 16722594.
  16. ↑ Watts RA, Scott DG (October 2016). “Vasculitis and inflammatory arthritis”. Best Pract Res Clin Rheumatol. 30 (5): 916–931. doi:10.1016/j.berh.2016.10.008. PMID 27964796.
  17. ↑ Avouac, J.; Clements, P. J.; Khanna, D.; Furst, D. E.; Allanore, Y. (2012). “Articular involvement in systemic sclerosis”. Rheumatology. 51 (8): 1347–1356. doi:10.1093/rheumatology/kes041. ISSN 1462-0324.
  18. ↑ Briemberg HR, Amato AA (September 2003). “Dermatomyositis and Polymyositis”. Curr Treat Options Neurol. 5 (5): 349–356. PMID 12895397.
  19. ↑ Kadavath S, Efthimiou P (February 2015). “Adult-onset Still’s disease-pathogenesis, clinical manifestations, and new treatment options”. Ann. Med. 47 (1): 6–14. doi:10.3109/07853890.2014.971052. PMID 25613167.
  20. ↑ Sugawara S, Ehara S, Hitachi S, Sugimoto H (March 2010). “Hand and wrist arthritis of Behçet disease: imaging features”. Acta Radiol. 51 (2): 183–6. doi:10.3109/02841850903401349. PMID 20121672.
  21. ↑ Emmungil H, Aydın SZ (2015). “Relapsing polychondritis”. Eur J Rheumatol. 2 (4): 155–159. doi:10.5152/eurjrheum.2015.0036. PMC 5047229. PMID 27708954.
  22. ↑ Iannuzzi MC, Rybicki BA, Teirstein AS (November 2007). “Sarcoidosis”. N. Engl. J. Med. 357 (21): 2153–65. doi:10.1056/NEJMra071714. PMID 18032765.
  23. ↑ Iyer VR, Cohen GL (February 2011). “Palindromic rheumatism”. South. Med. J. 104 (2): 147–9. doi:10.1097/SMJ.0b013e318200c4cc. PMID 21206416.
  24. ↑ Yildirim K, Uzkeser H, Uyanik A, Karatay S, Kiziltunc A (2011). “Trace element levels in patients with familial mediterranean Fever”. Eurasian J Med. 43 (2): 79–82. doi:10.5152/eajm.2011.18. PMC 4261345. PMID 25610168.
  25. ↑ Soubrier, Martin; Dubost, Jean Jacques; Thiéblot, Philippe; Ristori, Jean Michel (2009). “Oligo-arthritis and type IV hyperlipoproteinemia”. Joint Bone Spine. 76 (1): 95–97. doi:10.1016/j.jbspin.2008.03.009. ISSN 1297-319X.
  26. ↑ Ganem, Don; Prince, Alfred M. (2004). “Hepatitis B Virus Infection — Natural History and Clinical Consequences”. New England Journal of Medicine. 350 (11): 1118–1129. doi:10.1056/NEJMra031087. ISSN 0028-4793.
  27. ↑ Spruance SL, Metcalf R, Smith CB, Griffiths MM, Ward JR (March 1977). “Chronic arthropathy associated with rubella vaccination”. Arthritis Rheum. 20 (2): 741–7. PMID 849368.
  28. ↑ Moore TL (July 2000). “Parvovirus-associated arthritis”. Curr Opin Rheumatol. 12 (4): 289–94. PMID 10910181.
  29. ↑ Bellato E, Marini E, Castoldi F, Barbasetti N, Mattei L, Bonasia DE; et al. (2012). “Fibromyalgia syndrome: etiology, pathogenesis, diagnosis, and treatment”. Pain Res Treat. 2012: 426130. doi:10.1155/2012/426130. PMC 3503476. PMID 23213512.
  30. ↑ McLean RM, Podell DN (February 1995). “Bone and joint manifestations of hypothyroidism”. Semin. Arthritis Rheum. 24 (4): 282–90. PMID 7740308.
  31. ↑ Magrinelli F, Zanette G, Tamburin S (October 2013). “Neuropathic pain: diagnosis and treatment”. Pract Neurol. 13 (5): 292–307. doi:10.1136/practneurol-2013-000536. PMID 23592730.
  32. ↑ SkowroÅ„ska-Jóźwiak E, Lorenc RS (2006). “Metabolic bone disease in children : etiology and treatment options”. Treat Endocrinol. 5 (5): 297–318. PMID 17002489.
  33. ↑ Trivedi MH (2004). “The link between depression and physical symptoms”. Prim Care Companion J Clin Psychiatry. 6 (Suppl 1): 12–6. PMC 486942. PMID 16001092.

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Chandrakala Yannam, MD [2], Mehrian Jafarizade, M.D [3], Eiman Ghaffarpasand, M.D. [4]