eMedicine Specialties > Emergency Medicine > Dermatology

Psoriasis: Differential Diagnoses & Workup

Author: Richard Gordon Jr, MD, Staff Physician, Department of Emergency Medicine, Detroit Receiving Hospital University Health Center
Coauthor(s): Adam J Rosh, MD, MS, Assistant Professor, Department of Emergency Medicine, Wayne State University/Detroit Receiving Hospital
Contributor Information and Disclosures

Updated: Apr 10, 2009

Differential Diagnoses

Dermatitis, Atopic
Pityriasis Rosea
Dermatitis, Contact
Reactive Arthritis
Gout and Pseudogout
Syphilis
Pityriasis Alba
Tinea

Other Problems to Be Considered

Seborrheic dermatitis
Diaper dermatitis
Onychomycosis
Squamous cell carcinoma
Nummular eczema
Lichen planus
Lichen simplex chronicus
Mycosis fungoides
Subcorneal pustulosis
Pustular eruptions

Workup

Laboratory Studies

  • Laboratory studies and findings for patients with psoriasis may include the following:
    • Test result for rheumatoid factor (RF) is negative.
    • Erythrocyte sedimentation rate (ESR) is usually normal.
    • Uric acid level may be elevated in psoriasis, causing confusion with gout in psoriatic arthritis.
    • Fluid from vesicles or pustules is sterile with lymphocytic infiltrate.
    • Perform latex fixation test.
    • Perform fungal studies.

Imaging Studies

  • Radiographs of affected joints can be helpful in differentiating types of arthritis.
  • Bone scans can identify joint involvement early.

Other Tests

  • If starting systemic therapies such as immunological inhibitors, consider obtaining baseline laboratory studies (ie, CBC, BUN/Cre, LFTs, hepatitis panel, tuberculosis [TB] screening).

Procedures

  • Although most cases of psoriasis are diagnosed clinically, some, particularly the pustular forms, can be difficult to recognize. In these cases, dermatologic biopsy can be used to make diagnosis.

More on Psoriasis

Overview: Psoriasis
Differential Diagnoses & Workup: Psoriasis
Treatment & Medication: Psoriasis
Follow-up: Psoriasis
Multimedia: Psoriasis
References
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References

  1. Krueger JG, Bowcock A. Psoriasis pathophysiology: current concepts of pathogenesis. Ann Rheum Dis. Mar 2005;64 Suppl 2:ii30-6. [Medline].

  2. Gelfand JM, Troxel AB, Lewis JD, et al. The risk of mortality in patients with psoriasis: results from a population-based study. Arch Dermatol. Dec 2007;143(12):1493-9. [Medline].

  3. Rapp SR, Feldman SR, Exum ML, et al. Psoriasis causes as much disability as other major medical diseases. J Am Acad Dermatol. Sep 1999;41(3 Pt 1):401-7. [Medline].

  4. Pettey AA, Balkrishnan R, Rapp SR, et al. Patients with palmoplantar psoriasis have more physical disability and discomfort than patients with other forms of psoriasis: implications for clinical practice. J Am Acad Dermatol. Aug 2003;49(2):271-5. [Medline].

  5. Sampogna F, Tabolli S, Soderfeldt B, et al. Measuring quality of life of patients with different clinical types of psoriasis using the SF-36. Br J Dermatol. May 2006;154(5):844-9. [Medline].

  6. Bowcock AM. Genetic locus for psoriasis identified. Ann Med. Apr 1995;27(2):183-6. [Medline].

  7. Bowcock AM, Barker JN. Genetics of psoriasis: the potential impact on new therapies. J Am Acad Dermatol. Aug 2003;49(2 Suppl):S51-6. [Medline].

  8. Bruce AJ, Rogers RS 3rd. Oral psoriasis. Dermatol Clin. Jan 2003;21(1):99-104. [Medline].

  9. Cuellar ML, Espinoza LR. Psoriatic arthritis. Current developments. J Fla Med Assoc. May 1995;82(5):338-42. [Medline].

  10. de Korte J, Sprangers MA, Mombers FM, et al. Quality of life in patients with psoriasis: a systematic literature review. J Investig Dermatol Symp Proc. Mar 2004;9(2):140-7. [Medline].

  11. Elder JT, Henseler T, Christophers E, et al. Of genes and antigens: the inheritance of psoriasis. J Invest Dermatol. Nov 1994;103(5 Suppl):150S-153S. [Medline].

  12. Farber EM. Therapeutic perspectives in psoriasis. Int J Dermatol. Jul 1995;34(7):456-60. [Medline].

  13. Farber EM, Nall L. Psoriasis. A review of recent advances in treatment. Drugs. Oct 1984;28(4):324-46. [Medline].

  14. Gelfand JM, Feldman SR, Stern RS, et al. Determinants of quality of life in patients with psoriasis: a study from the US population. J Am Acad Dermatol. Nov 2004;51(5):704-8. [Medline].

  15. Greaves MW, Weinstein GD. Treatment of psoriasis. N Engl J Med. Mar 2 1995;332(9):581-8. [Medline].

  16. Heydendael VM, de Borgie CA, Spuls PI, et al. The burden of psoriasis is not determined by disease severity only. J Investig Dermatol Symp Proc. Mar 2004;9(2):131-5. [Medline].

  17. Krueger GG, Feldman SR, Camisa C, Duvic M, Elder JT,Gottlieb AB, et al. Two considerations for patients with psoriasis and their clinicians: what defines mild, moderate,and severe psoriasis? What constitutes a clinically significant improvement when treating psoriasis?. J Am Acad Dermatol. 2000;43:281-5. [Medline].

  18. Lebwohl M. Combining the new biologic agents with our current psoriasis armamentarium. J Am Acad Dermatol. Aug 2003;49(2 Suppl):S118-24. [Medline].

  19. Lebwohl MG. The evolution of vitamin D analogues for the treatment of psoriasis. Arch Dermatol. Nov 1995;131(11):1323-4. [Medline].

  20. Lewis HM. Therapeutic progress. II: Treatment of psoriasis. J Clin Pharm Ther. Aug 1994;19(4):223-32. [Medline].

  21. Mease PJ, Menter MA. Quality-of-life issues in psoriasis and psoriatic arthritis: outcome measures and therapies from a dermatological perspective. J Am Acad Dermatol. Apr 2006;54(4):685-704. [Medline].

  22. Menter A, Gottlieb A, Feldman SR, et al. Guidelines of care for the management of psoriasis and psoriatic arthritis: Section 1. Overview of psoriasis and guidelines of care for the treatment of psoriasis with biologics. J Am Acad Dermatol. May 2008;58(5):826-50. [Medline].

  23. Menter MA, Krueger GC, Feldman SR, et al. Psoriasis treatment 2003 at the new millennium: position paper on behalf of the authors. J Am Acad Dermatol. Aug 2003;49(2 Suppl):S39-43. [Medline].

  24. Naldi L. Psoriasis. Dermatol Clin. Jul 1995;13(3):635-47. [Medline].

  25. Ortonne JP, Lebwohl M, Em Griffiths C. Alefacept-induced decreases in circulating blood lymphocyte counts correlate with clinical response in patients with chronic plaque psoriasis. Eur J Dermatol. Mar-Apr 2003;13(2):117-23. [Medline].

  26. Pines A, Ehrenfeld M, Fisman EZ, et al. Mitral valve prolapse in psoriatic arthritis. Arch Intern Med. Jul 1986;146(7):1371-3. [Medline].

  27. Raychaudhuri SP, Rein G, Farber EM. Neuropathogenesis and neuropharmacology of psoriasis. Int J Dermatol. Oct 1995;34(10):685-93. [Medline].

  28. Sen P, Chan R. A Case Report of Severe Psoriasis in a Patient with AIDS: The Role of the HIV Virus and the Therapeutic Challenges Involved. National Skin Center (NSC). Available at http://www.nsc.gov.sg/cgi-bin/WB_ContentGen.pl?id=401&gid=83.

  29. Stern RS, Nijsten T, Feldman SR, et al. Psoriasis is common, carries a substantial burden even when not extensive, and is associated with widespread treatment dissatisfaction. J Investig Dermatol Symp Proc. Mar 2004;9(2):136-9. [Medline].

  30. Task Force on Psoriasis. Guidelines of care for psoriasis. Committee on Guidelines of Care. Task Force on Psoriasis. J Am Acad Dermatol. Apr 1993;28(4):632-7. [Medline].

  31. Valdimarsson H, Sigmundsdottir H, Jonsdottir I. Is psoriasis induced by streptococcal superantigens and maintained by M-protein-specific T cells that cross-react with keratin?. Clin Exp Immunol. Jan 1997;107 Suppl 1:21-4. [Medline].

  32. Weinstein GD. Tazarotene: A novel retinoid for the topical treatment of psoriasis. Pharmacy and Therapeutics. Aug 1997;377-81. [Medline].

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Further Reading

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Keywords

psoriasis, skin itching, itchy skin, scaly skin, psoriasis treatment, psoriasis symptoms, discoid psoriasis, plaque psoriasis, guttate psoriasis, skin disorder, skin lesions, oral psoriasis, nail psoriasis, psoriatic arthritis, scalp psoriasis, erythrodermic psoriasis, pustular psoriasis, inverse psoriasis

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Contributor Information and Disclosures

Author

Richard Gordon Jr, MD, Staff Physician, Department of Emergency Medicine, Detroit Receiving Hospital University Health Center
Richard Gordon Jr, MD is a member of the following medical societies: American College of Emergency Physicians, American College of Physicians, American Medical Student Association/Foundation, Emergency Medicine Residents Association, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Coauthor(s)

Adam J Rosh, MD, MS, Assistant Professor, Department of Emergency Medicine, Wayne State University/Detroit Receiving Hospital
Adam J Rosh, MD, MS is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Medical Editor

Dana A Stearns, MD, Assistant Director of Undergraduate Education, Department of Emergency Medicine, Massachusetts General Hospital
Dana A Stearns, MD is a member of the following medical societies: American Academy of Emergency Medicine and American College of Emergency Physicians
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Mark W Fourre, MD, Program Director, Department of Emergency Medicine, Maine Medical Center; Associate Clinical Professor, Department of Surgery, University of Vermont School of Medicine
Disclosure: Nothing to disclose.

CME Editor

John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center
John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Chief Editor

Robert E O'Connor, MD, MPH, Professor and Chair, Department of Emergency Medicine, University of Virginia Health System
Robert E O'Connor, MD, MPH is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, American College of Physician Executives, American Heart Association, American Medical Association, Medical Society of Delaware, National Association of EMS Physicians, Society for Academic Emergency Medicine, and Wilderness Medical Society
Disclosure: Nothing to disclose.

 
 
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