Fast Five Quiz: What Do You Know About Psoriasis?

Dirk M Elston, MD; William James, MD


January 25, 2023

Laboratory studies and findings for patients with psoriasis may include:

  • Test result for rheumatoid factor is negative.

  • Erythrocyte sedimentation rate is usually normal (except in pustular and erythrodermic psoriasis).

  • Uric acid level may be elevated in psoriasis (especially in pustular psoriasis), causing confusion with gout in psoriatic arthritis.

  • Fluid from pustules is sterile with neutrophilic infiltrate.

  • Perform fungal studies. (This is especially important in cases of hand and foot psoriasis that seem to be worsening with the use of topical steroids.)

If starting systemic therapies such as immunologic inhibitors, consider obtaining baseline laboratory studies (ie, complete blood count, blood urea nitrogen/creatinine, liver function tests, hepatitis panel, tuberculosis screening).

Learn more about the workup of psoriasis.


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