Percentage of each diagnostic category among patients seen in the emergency department (ED) for skin conditions. Among patients with skin infections, the fraction of those diagnosed as having cellulitis is in red.
Seasonal distribution of emergency department (ED) visits for skin conditions. The peaks in the number of visits occur consistently in the summer months.
Baibergenova A, Shear NH. Skin Conditions That Bring Patients to Emergency Departments. Arch Dermatol. 2011;147(1):118-120. doi:10.1001/archdermatol.2010.246
Skin diseases are common in the general population. The prevalence of dermatologic conditions that require medical treatment is estimated to range from 19% to 27%, with acne and eczema being the most common skin diseases.1,2 Yet, skin complaints account for only about 7% of all outpatient clinic visits,3 possibly because of the benign nature (both the true and the perceived) of most skin conditions. Perhaps this, as well as the low acute mortality of common dermatologic conditions, could also explain the lack of studies on emergency department (ED) visits that are attributable to skin diseases. Our study aimed to fill this gap and looked at the epidemiology of ED visits due to skin conditions.
The database used for this study was the National Ambulatory Care Records System, which is managed by the Canadian Institute for Health Information. The National Ambulatory Care Records System is a clinical administrative database with information on patient visits to EDs and day surgery units. It includes basic demographic, clinical, and administrative data.
For the study, we selected the records of patients who visited Ontario EDs between April 1, 2002, and March 31, 2007, and had a principal diagnosis of “diseases of the skin and subcutaneous tissue” (International Statistical Classification of Diseases, 10th Revision, codes L00-L99). Note that diagnoses recorded in this database are predominantly made by ED physicians, and it is impossible to discern whether the patient was seen by dermatology consulting services during the visit.
Statistical analysis of the data was performed using SAS software (Version 9.1; SAS Institute Inc, Cary, North Carolina). The study was approved by the University of Toronto Research Ethics Board.
Over a 5-year period, there were 866 976 ED visits attributable to skin conditions in Ontario province, with an annual average of 173 395 visits. For comparison, the number of Ontario EDs visits due to all causes in 2005 was 5 216 000,4 meaning that skin complaints account for about 3.3% of all ED visits. There was an approximately equal number of male and female patients. The mean (SD) age was 39.4 (23.5) years, with noticeable overrepresentation of patients at the extremes of ages: infants and persons older than 80 years. Most cases (75%) were triaged as either nonurgent or semiurgent, with only 2% having emergency status. Ninety-four percent of patients were discharged home after a visit, and only 4% required inpatient admission.
Infections of skin and subcutaneous tissue were responsible for more than half of ED visits, followed by dermatitis, urticaria, and disorders of skin appendages (Figure 1). Of note, bullous disorders accounted for only 0.06% of visits. When stratified by age group, skin infections remained the most prevalent cause of ED visits in older children and adults, while they were outnumbered by dermatitis in infants and urticaria in preschool children (data not shown). When looking at the specific diagnoses, the most common diagnosis that represented most skin infections was cellulitis, which was diagnosed in 30.4% of patients (Figure 1). Among inpatient admissions, a diagnosis of cellulitis was made in 71.4% of patients. Another interesting finding was a presence of striking seasonal variation in ED visits (Figure 2). Over a 5-year study period, the number of visits consistently peaked in July and August and decreased in February.
As expected, dermatologic diseases account for a relatively small fraction of all ED visits, about 3.3%. Although it has not been shown previously, it is not surprising that the skin infections are the most common cause of ED visit and hospital admission from ED. The predominance of skin infections among causes of visits might explain the distinct seasonal variation observed in this study. The summer peaks of ED visits suggest that seasonal factors such as heat and humidity, increased outdoor activities, and higher frequency of insect bites might be implicated as triggers. Of note, a very different seasonal pattern in ED visits has been reported for other conditions, such as asthma, with peaks of visits in the fall, and heart attacks, with peaks of visits in winter months.
A significant percentage of patients seen in the ED were diagnosed as having cellulitis (30.4%). Remarkably, cellulitis was also responsible for more than two-thirds of all inpatient admissions for skin diseases. Although cellulitis is not an uncommon condition, some degree of overdiagnosis cannot be ruled out given that diagnoseswere made by ED physicians. A recent pilot study showed that among patients admitted inpatient or to an observational unit for cellulitis, the diagnosis was changed after the patients were seen by consulting services (dermatology and infectious diseases) in 20% of cases.5 Therefore, we believe that further investigation is needed to find out what the most common mimickers of cellulitis that are encountered by ED physicians are and whether the diagnosis of dermatologic conditions is influenced by the attending physician's specialty.
Correspondence: Dr Baibergenova, Division of Dermatology, University of Toronto, Sunnybrook Health Sciences Center, 2075 Bayview Ave, M1-700, Toronto ON, M4N 3M5, Canada (firstname.lastname@example.org).
Accepted for Publication: July 23, 2010.
Published Online: September 20, 2010. doi:10.1001/archdermatol.2010.246
Author Contributions: Dr Baibergenova had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Baibergenova and Shear. Acquisition of data: Baibergenova and Shear. Analysis and interpretation of data: Baibergenova and Shear. Drafting of the manuscript: Baibergenova and Shear. Critical revision of the manuscript for important intellectual content: Baibergenova and Shear. Statistical analysis: Baibergenova. Obtained funding: Baibergenova and Shear. Administrative, technical, and material support: Baibergenova and Shear. Study supervision: Shear.
Financial Disclosure: None reported.
Additional Contributions: The Canadian Institute for Health Information provided data for this study.