Skin Manifestations of Outpatient Adverse Drug Events in the United States: A National Analysis

Abstract

Background: Cutaneous reactions to drugs are among the most common clinical manifestations of adverse drug events (ADEs); however, data on outpatient cutaneous adverse drug events (CADEs) are limited. Purpose: To provide national estimates of outpatient CADEs and determine their most frequent causes. Methods: Outpatient CADEs recorded in the National Ambulatory Medical Care Survey (NAMCS) and the National Hospital Ambulatory Medical Care Survey (NHAMCS) between 1995 and 2005 were analyzed. The national incidence of outpatient CADEs in those seeking medical attention in the United States was estimated, and the common medication classes implicated with CADEs were identified. Results: There were a mean annual total of 635,982 CADE-related visits, resulting in an annual incidence of 2.26 CADEs per 1,000 persons. Patients took an average of 2.2 medications in addition to the one causing the CADE. The incidence of CADEs increased with age, with a peak in the age group from 70 to 79 years. The medications most frequently causing a CADE were antimicrobial agents. Dermatitis and urticaria were the two main types of skin reactions reported. Conclusions: CADEs occur less frequently in outpatients than in inpatients and result in few hospital admissions. Physicians must be particularly cognizant of the occurrence of CADEs when prescribing antimicrobial agents.