Which of the following evaluations would be reasonable approaches?
This 37-year-old woman presented for a second opinion about a 1-year history of intractable pruritus that had failed to respond to any treatment. Short courses of prednisone, various antihistamines, and various topical corticosteroid creams had all failed. Results of a complete blood cell count and a comprehensive metabolic panel were unremarkable. The physical examination findings were unremarkable except for the skin changes seen here.
Which of the following evaluations would be reasonable approaches?
- 24-hour urine test for 5-hydroxyindoleacetic acid (5-HIAA) and serum tryptase test
- Hepatitis virus panel
- Thyroid function tests
- Chest radiography
- Skin biopsy
- Psychiatric evaluation
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Answer: All of the listed evaluations are reasonable approaches
All of the evaluations listed above would be reasonable choices in the approach to this case and other cases that feature a disproportionate degree of pruritus compared with the degree of dermatologic changes. This patient’s chest radiograph revealed a mediastinal mass, which was subsequently determined to be a result of Hodgkin lymphoma. Treatment of her lymphoma resulted in relief of her symptoms.
A 24-hour urine test for 5-HIAA and a serum tryptase tests investigate mastocytosis as a possible etiology of chronic pruritus. Hepatitis tests are appropriate, given the fact that hepatitis C virus infection can be a surreptitious cause of itching. A skin biopsy may discover dermatitis if immunofluorescence testing is done in addition to standard hematoxylin-eosin staining.
If no etiology can be identified, neurotic excoriations should be considered.
David L. Kaplan, MD, is a clinical assistant professor of dermatology at the University of Missouri–Kansas City School of Medicine in Kansas City, Missouri, and at the University of Kansas School of Medicine in Kansas City, Kansas. He practices adult and pediatric dermatology in Overland Park, Kansas.