SAN FRANCISCO — Patients with pruritus are twice as likely to have a comorbid psychiatric diagnosis as those with other dermatologic diagnoses, according to a large epidemiologic study.
This association is driven largely by the strong association between pruritus and comorbid anxiety disorders, Dr. Madhulika A. Gupta reported at the annual meeting of the American Academy of Dermatology.
The link between pruritus and obsessive compulsive disorder (OCD) was particularly robust.
In this analysis representing more than 33 million dermatologic physician/patient encounters, patients with an International Classification of Diseases 9th edition Clinical Modification diagnosis of pruritus were 11.3-fold more likely than all other dermatology patients to have a comorbid diagnosis of OCD, according to Dr. Gupta, a psychiatrist at the University of Western Ontario, London.
She analyzed epidemiologic data from the National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey for 1995–2003.
These surveys conducted by the U.S. National Center for Health Statistics encompassed an estimated 33.6 million dermatology-related patient visits to physicians' offices, clinics, and emergency departments.
Patients diagnosed with pruritus, as indicated by ICD-9-CM codes 698.0–698.9, were 4.6-fold more likely to have a comorbid anxiety disorder than were patients who had other dermatologic diagnoses.
To Dr. Gupta's surprise, pruritus was not associated with a significantly increased likelihood of comorbid major depressive disorder. She suspects this was because there was a substantial prevalence of major depressive disorder among the comparison group comprised of patients with other dermatologic disorders.
A signal that pruritus may be associated with an increased likelihood of comorbid depression was evident in the finding that physicians responded affirmatively to the survey checklist question “Is the patient depressed?” Depression was 3.3 times more frequent when the patient in question had pruritus, Dr. Gupta added.