Most Common Dermatologic Conditions Encountered by Dermatologists and Nondermatologists

Skin diseases are highly prevalent in the United States, affecting an estimated 1 in 3 Americans at any given time.^1,2 In 2009 the direct medical costs associated with skin-related diseases, including health services and prescriptions, was approximately $22 billion; the annual total economic burden was estimated to be closer to $96 billion when factoring in the cost of lost productivity and pay for symptom relief.^3,4 Effective and efficient management of skin disease is essential to minimizing cost and morbidity. Nondermatologists traditionally have diagnosed the majority of skin diseases.^5,6 In particular, primary care physicians commonly manage dermatologic conditions and often are the first health care providers to encounter patients presenting with skin problems. A predicted shortage of dermatologists will likely contribute to an increase in this trend.^7,8 Therefore, it is important to adequately prepare nondermatologists to evaluate and treat the skin conditions that they are most likely to encounter in their scope of practice.

Residents, particularly in primary care specialties, often have opportunities to spend 2 to 4 weeks with a dermatologist to learn about skin diseases; however, the skin conditions most often encountered by dermatologists may differ from those most often encountered by physicians in other specialties. For instance, one study demonstrated a disparity between the most common skin problems seen by dermatologists and internists.⁹ These dissimilarities should be recognized and addressed in curriculum content. The purpose of this study was to identify and compare the 20 most common dermatologic conditions reported by dermatologists versus those reported by nondermatologists (ie, internists, pediatricians, family physicians, emergency medicine physicians, general surgeons, otolaryngologists) from 2001 to 2010. Data also were analyzed to determine the top 20 conditions referred to dermatologists by nondermatologists as a potential indicator for areas of further improvement within medical education. With this knowledge, we hope educational curricula and self-study can be modified to reflect the current epidemiology of cutaneous diseases, thereby improving patient care.

Methods

Data from 2001 to 2010 were extracted from the National Ambulatory Medical Care Survey (NAMCS), which is an ongoing survey conducted by the National Center for Health Statistics. The NAMCS collects descriptive data regarding ambulatory visits to nonfederal office-based physicians in the United States. Participating physicians are instructed to record information about patient visits for a 1-week period, including patient demographics, insurance status, reason for visit, diagnoses, procedures, therapeutics, and referrals made at that time. Data collected for the NAMCS are entered into a multistage probability sample to produce national estimates. Within dermatology, an average of 118 dermatologists are sampled each year, and over the last 10 years, participation rates have ranged from 47% to 77%.

International Classification of Diseases, Ninth Revision, Clinical Modification codes were identified to determine the diagnoses that could be classified as dermatologic conditions. Select infectious and neoplastic disorders of the skin and mucous membrane conditions were included as well as the codes for skin diseases. Nondermatologic diagnoses and V codes were not included in the study. Data for all providers were studied to identify outpatient visits associated with the primary diagnosis of a dermatologic condition. Minor diagnoses that were considered to be subsets of major diagnoses were combined to allow better analysis of the data. For example, all tinea infections (ie, dermatophytosis of various sites, dermatomycosis unspecified) were combined into 1 diagnosis referred to as tinea because the recognition and treatment of this disease does not vary tremendously by anatomic location. Visits to dermatologists that listed nonspecific diagnoses and codes (eg, other postsurgical status [V45.89], neoplasm of uncertain behavior site unspecified [238.9]) were assumed to be for dermatologic problems.

Sampling weights were applied to obtain estimates for the number of each diagnosis made nationally. All data analyses were performed using SAS software and linear regression models were generated using SAS PROC SURVEYREG.

Data were analyzed to determine the dermatologic conditions most commonly encountered by dermatologists and nondermatologists in emergency medicine, family medicine, general surgery, internal medicine, otolaryngology, and pediatrics; these specialties include physicians who are known to commonly diagnose and treat skin diseases.¹⁰ Data also were analyzed to determine the most common conditions referred to dermatologists for treatment by nondermatologists from the selected specialties. Permission to conduct this study was obtained from the Wake Forest University institutional review board (Winston-Salem, North Carolina).