Epidemiology of dermatitis and skin infections in United States physicians' offices, 1993-2005.

BACKGROUND: Since the discovery of community-associated methicillin-resistant Staphylococcus aureus (MRSA), the number of emergency department visits for skin and soft-tissue infection (SSTI) has increased, and one report suggested an increase in the much larger setting of physicians' offices. Dermatitis compromises the cutaneous barrier to microorganisms and may predispose to SSTI. Our objectives were to determine whether office visits for dermatitis or SSTI have become more frequent since the emergence of community-associated MRSA, to describe the age-specific frequency of visits for dermatitis and SSTI, and to determine whether dermatitis is associated with SSTI and whether the association strengthened over time.

METHODS: We analyzed visits for the diagnoses of dermatitis and SSTI by means of codes from the International Classification of Diseases, Ninth Revision recorded in the National Ambulatory Medical Care Survey, 1993-2005. We calculated population estimates by year and age group, with 95% confidence intervals (CIs), and examined trends over time. Multivariate logistic regression quantified the association between dermatitis and SSTI and assessed for interaction between dermatitis and year in the prediction of SSTI.

RESULTS: Dermatitis was diagnosed at 13 million office visits per year (95% CI, 12-14 million office visits per year) over the study period, and SSTI was diagnosed at 6.3 million office visits per year (95% CI, 5.8 million-6.8 million office visits per year). The frequency did not change for either diagnosis over time when expressed as a percentage of all visits (both, p < .60). Dermatitis was most common among infants (256 visits per 1,000 population per year; 95% CI, 216-293 visits per 1,000 population per year). The rate of diagnosis of SSTI did not vary importantly by age. Dermatitis was associated with SSTI (odds ratio, 2.54; 95% CI, 1.92-3.35). The association did not strengthen over time.

CONCLUSIONS: The rate of office visits for dermatitis or SSTI did not increase from 1993 through 2005. Dermatitis was associated with SSTI. This association did not strengthen as community-associated MRSA became prevalent.