Abstract
Background
Scabies is a contagious skin infestation caused by Sarcoptes scabiei and affects over 200 million people worldwide. Changes in behaviour and living conditions during the COVID-19 pandemic may have influenced its transmission dynamics. This study aimed to evaluate temporal trends and epidemiological characteristics of scabies-related emergency department (ED) visits.
Methods
In this single-centre retrospective ED-based trend analysis, 10,994 scabies-related emergency department visits recorded with a principal diagnosis of scabies between January 2022 and October 2023 were analyzed. Descriptive statistics and negative binomial regression were used to assess temporal trends and associated factors.
Results
Of all visits, 10,434 (94.9%) were initial and 560 (5.1%) were early repeat visits. The mean age was 22.3 ± 18.1 years, and 57.2% of visits occurred in males. Monthly visit counts fluctuated over time, ranging from 236 in January 2022 to a peak of 737 in December 2022. Negative binomial regression indicated a significant average monthly increase in ED visit counts (IRR = 1.04, 95% CI: 1.03–1.07, p < 0.001), and provided a substantially better fit than Poisson regression (ΔAIC > 500). However, in the denominator-adjusted sensitivity analysis using monthly green-zone ED visits as an offset, the temporal increase was attenuated and was not statistically significant (IRR = 1.01, 95% CI: 0.99–1.03, p = 0.268).
Conclusion
Scabies-related ED visits increased during the observation period; however, these findings should be interpreted as increased ED visit burden rather than direct evidence of population-level incidence. Strengthened surveillance, early recognition, contact management, and adherence-focused interventions may help reduce scabies-related healthcare burden.
Keywords: Dermatology, epidemiology, recurrence, scabies
Introduction
Scabies is a common parasitic skin disease caused by the Sarcoptes scabiei var. hominis mite. The infestation, which develops when the mite burrows into the upper layer of the epidermis, triggers an inflammatory response characterized by intense itching. Transmission typically occurs through prolonged skin-to-skin contact, although indirect transmission via infested clothing, bedding, or other items is also possible [1]. Clinically, scabies is characterized by tunnels, papules, and vesicles, particularly between the fingers, in the axillae, genital area, and around the waist, and is often accompanied by severe itching that worsens at night [2]. The prevalence of the disease varies widely depending on factors such as socioeconomic conditions, population density, hygiene practices, and access to healthcare, ranging from 0.2% to 71% [1]. Outbreaks are particularly common in closed or semi-closed environments such as schools, nursing homes, prisons, and military units [3]. In recent years, an increasing trend in scabies cases has been reported in many countries, and a similar pattern is observed in Turkey. Data from various centres indicate a significant increase in case numbers, particularly during the pre-pandemic and pandemic periods [4,5]. It is believed that social isolation, changes in hygiene behaviours, and limited access to healthcare services during the COVID-19 pandemic may have influenced the transmission dynamics of scabies [6,7].
Scabies is not limited to pruritus and dermatological symptoms but may also lead to significant complications, including secondary bacterial infections (e.g. impetigo, cellulitis) and immunological sequelae such as post-streptococcal glomerulonephritis and acute rheumatic fever [8,9]. Recognized as a significant public health issue on a global scale, scabies was included in the World Health Organization’s list of Neglected Tropical Diseases (NTDs) in 2017 [10]. When examining the global disease burden, it is estimated that there were approximately 204 million scabies cases worldwide as of 2015 [11]. Recent epidemiological studies across multiple countries support this increasing trend. For example, a large retrospective study from Spain reported a rise in scabies incidence across all data sources between 2011 and 2023, with a marked acceleration after 2020–2021 [12]. Similarly, a study in South Korea based on national health insurance data revealed that prevalence was particularly higher among individuals aged 80 and older [13]. Controlling scabies outbreaks can be particularly challenging in closed settings such as nursing homes and prisons. One of the main reasons for this is delays in diagnosis [14]. To standardize diagnostic processes, the International Alliance for the Control of Scabies (IACS) developed consensus diagnostic criteria in 2020, comprising three levels of diagnostic certainty (confirmed, clinical, and suspected), which were validated in the same year [15]. These criteria contribute to the standardization of diagnosis based on clinical findings, particularly in field studies where laboratory resources are limited.
In this context, this study examines the demographic characteristics, readmission patterns, and temporal trends of scabies-related emergency department visits in a tertiary care setting. By applying count-based temporal trend analysis, it aims to provide actionable epidemiological insights to inform targeted interventions and strengthen disease control strategies.
Materials and methods
Study design
This study was designed as a retrospective, single-centre, emergency department (ED)-based trend analysis to evaluate temporal changes in ED visits recorded with a principal diagnosis of scabies in the hospital electronic health record system between 1 January 2022 and 31 October 2023. The study was conducted in the ED of a tertiary teaching and research hospital in Türkiye. The hospital provides 24-hour emergency care and serves a large urban catchment area.
As the study period was limited to 22 months, the aim was to evaluate the overall temporal trend and seasonal variation in monthly ED visit counts rather than to develop a forecasting model; therefore, ARIMA-based time-series modeling was not performed.
Case definition and diagnostic approach
Scabies-related ED visits were identified from electronic health records using ICD-10 code B86 recorded as the principal diagnosis after clinical assessment and consultation when required. Records outside the study period, duplicate entries, and those with missing or inconsistent diagnostic or demographic data were excluded.
Diagnosis was based on clinical symptoms, examination findings, typical lesion distribution, and contact history, with dermatology consultation and dermoscopy when indicated. As parasitological confirmation was not available for all patients, the study population represents ED visits with a principal diagnosis of scabies rather than laboratory-confirmed cases. Visits were included regardless of discharge or admission; subsequent inpatient course and treatment response were not evaluated.
Repeat visits
Repeat visits within 20 days were classified as early repeat visits rather than confirmed new episodes, treatment failures, or drug resistance—a pragmatic threshold capturing short-term presentations (within an approximately 2–3-week window) that may reflect persistent symptoms, incomplete contact treatment, adherence issues, or early reinfestation [16–18]. Primary analyses included all visits to quantify overall ED burden; early repeat visits were also reported separately, and a sensitivity analysis restricted to initial visits assessed whether the temporal trend was driven by short-term repeats.
Patient selection and data collection
Demographic, visit-related, and temporal variables were extracted from the hospital electronic health record system. For each scabies-related ED visit, age, sex, nationality, date of presentation, year, month, and season were recorded. The original dataset consisted of individual ED visit records, with each row representing one scabies-related ED visit. Monthly visit counts were aggregated from these individual records for analysis.
Seasonal variation was assessed by categorizing months into winter (December–February), spring (March–May), summer (June–August), and autumn (September–November). Records outside the study period, duplicate administrative entries, and records with missing or inconsistent diagnostic or demographic information were excluded.
Statistical analysis
Descriptive statistics were reported as mean ± standard deviation (SD), median with interquartile range (IQR), and frequency with percentage, as appropriate. The normality of continuous variables was assessed using the Shapiro–Wilk test.
Overdispersion was assessed using the variance-to-mean ratio. The variance substantially exceeded the mean, indicating violation of the Poisson equidispersion assumption. Therefore, Poisson and negative binomial regression models were compared using the Akaike Information Criterion (AIC). The negative binomial model provided a substantially better fit than the Poisson model (AIC = 278.1 vs. 860.3; ΔAIC = 582.2) and was selected for the main analyses.
In the main model, monthly total scabies-related ED visit count was used as the dependent variable, and time, defined as a continuous variable in months, was included as the primary independent variable. Seasonal variation was assessed by including season as a categorical variable, with winter used as the reference category.
A spline-based sensitivity analysis was conducted to assess potential non-linearity. Model residuals were examined to assess residual temporal dependence. Autocorrelation was evaluated using autocorrelation function (ACF) and partial autocorrelation function (PACF) plots, and the Ljung–Box test was applied to Pearson residuals.
In addition to the overall monthly aggregated analysis, subgroup analyses were performed using monthly visit counts stratified by age group and sex (month × age group × sex). In these subgroup models, age group, sex, and the age group × sex interaction were evaluated in relation to monthly subgroup-specific visit counts. Because the age group × sex interaction was not statistically significant and did not improve model fit, the simpler model including time, age group, and sex was retained. As an additional denominator-adjusted sensitivity analysis, a negative binomial regression model was fitted using the monthly number of green-zone ED visits as an offset term to account for changes in overall green-zone emergency department attendance over time. All analyses were conducted using RStudio with the MASS, splines, and stats package. A two-sided p-value < 0.05 was considered statistically significant.
Results
A total of 10,994 scabies-related emergency department visits were analyzed to evaluate changes in ED visit burden during the 22-month observation period. Of these, 10,434 (94.9%) were initial visits, while 560 (5.1%) were early repeat visits occurring within 20 days. The number of unique patient identifiers (n = 10,434) matched the number of initial visits, confirming internal consistency in case classification. Multiple repeat visits (≥3) were rare (<0.3%). The mean age of patients was 22.3 ± 18.1 years, and the median age was 17 years (IQR 8–34). Adults aged 18–64 years accounted for the largest proportion of visits (44.7%), followed by school-aged children (21.0%) and adolescents (14.6%). Infants and elderly patients accounted for 5.4% and 2.9% of visits, respectively. Overall, 57.2% of visits occurred in males and 42.8% in females, indicating a slight male predominance (Table 1).
Table 1.
Descriptive characteristics.
| Variable | N | Percent (%) |
|---|---|---|
| Total Visits | 10,994 | |
| Initial Visit | 10,434 | 94.9 |
| Repeated Visits | 560 | 5.1 |
| Age Group | ||
| Infant (0–1 years) | 568 | 5.44 |
| Early Childhood (2–5 years) | 1,178 | 11.29 |
| School Age (6–12 years) | 2,191 | 21.00 |
| Adolescent (13–17 years) | 1,528 | 14.64 |
| Adult (18–64 years) | 4,668 | 44.74 |
| Senior (≥65 years) | 301 | 2.88 |
| Age (Scale) | ||
| Mean ± SD | 22.30 ± 18.10 | – |
| Median (IQR) | 17 (8–34) | – |
| Sex | ||
| Male | 5,967 | 57.19 |
| Female | 4,467 | 42.81 |
The mean monthly scabies-related visit count was 499.7 ± 164.6, with the variance substantially exceeding the mean, indicating marked overdispersion. Accordingly, the negative binomial model provided a substantially better fit than the Poisson model (AIC = 278.1 vs. 860.3) (Table 2).
Table 2.
Summary of monthly scabies-related emergency department visit counts.
| Statistics | Value |
|---|---|
| Mean ± SD | 499.7 ± 164.6 |
| Minimum | 236 (January 2022) |
| Maximum | 737 (December 2022) |
| Variance/Mean Ratio | 55 |
Monthly visit counts fluctuated over time, ranging from 236 visits in January 2022 to a peak of 737 visits in December 2022. After this peak, counts varied across 2023, reaching 732 visits in September 2023 and 512 visits in October 2023. This pattern suggests a fluctuating but overall increasing ED visit burden rather than a strictly linear increase (Figure 1). Residual diagnostics based on ACF and PACF plots did not suggest substantial residual temporal dependence. Consistently, the Ljung–Box test based on Pearson residuals did not indicate statistically significant autocorrelation in the residuals of the negative binomial regression model at either lag 4 or lag 6 (lag 4: χ2 = 5.99, p = 0.200; lag 6: χ2 = 6.09, p = 0.413). The natural cubic spline model provided a better fit than the linear trend model (AIC = 268.5 vs. 278.1; LRT: χ2 = 13.62, p = 0.001), suggesting that the temporal pattern included non-linear fluctuations, most notably the peak observed in late 2022. Nevertheless, the overall upward trend remained consistent across both model specifications.
Figure 1.
Monthly scabies-related emergency department visits and temporal trends during the study period (January 2022–October 2023). (A) Observed monthly scabies-related ED visit counts with linear and spline-based model-estimated temporal trends. (B) Trends in total and initial visits over time. (C) Model-estimated temporal trend with 95% confidence intervals from the negative binomial regression model.
During the same period, scabies-related visits accounted for approximately 1.74% of all green-zone examinations overall, equivalent to 174.3 scabies-related visits per 10,000 green-zone examinations. In a denominator-adjusted sensitivity analysis using monthly green-zone ED visits as an offset, the temporal increase was attenuated and was not statistically significant (IRR = 1.01, 95% CI: 0.99–1.03, p = 0.268). Therefore, these findings should be interpreted as changes in scabies-related ED visit burden during the 22-month observation period rather than as direct evidence of a long-term increase in population-level scabies incidence.
In subgroup analyses based on monthly visit counts stratified by age group and sex, time remained independently associated with increasing visit counts. Each monthly increase was associated with a 4% increase in visit frequency (IRR = 1.04, 95% CI 1.03–1.07, p < 0.001). Age group and sex were also found to be independently associated with visit frequency (both p < 0.001). Compared to infants (reference category), adults showed the highest relative frequency (IRR = 7.76), followed by school-aged children (IRR = 3.72) and adolescents (IRR = 2.61); elderly patients, however, exhibited a lower relative frequency (IRR = 0.54). Female sex was associated with lower visit counts compared to males (IRR = 0.76, p < 0.001). The age- sex interaction term was not statistically significant (p = 0.59) and its inclusion did not improve model fit; therefore, the simple model without the interaction term was retained (Table 3; Figure 2).
Table 3.
Negative binomial regression analysis of monthly scabies-related visit counts stratified by age group and sex.
| Variable | IRR | 95% CI | p |
|---|---|---|---|
| Time (per month) | 1.04 | 1.03-1.07 | <0.001 |
| Age Group | <0.001 | ||
| Infant (Reference) | 1.00 | – | – |
| Early childhood vs. Infant | 2.03 | 1.71–2.40 | <0.001 |
| School age vs. Infant | 3.72 | 3.16–4.38 | <0.001 |
| Adolescent vs. Infant | 2.61 | 2.21–3.08 | <0.001 |
| Adult vs. Infant | 7.76 | 6.61–9.12 | <0.001 |
| Senior vs. Infant | 0.54 | 0.45–0.65 | <0.001 |
| Sex | <0.001 | ||
| Male (Reference) | 1.00 | – | – |
| Female vs. Male | 0.76 | 0.69–0.83 | <0.001 |
| Age: Sex Interaction | 0.59 | ||
| Early childhood × Female | 0.99 | 0.71–1.39 | 0.97 |
| School age × Female | 0.91 | 0.66–1.25 | 0.56 |
| Adolescent × Female | 0.94 | 0.68–1.30 | 0.70 |
| Adult × Female | 0.79 | 0.58–1.09 | 0.15 |
| Senior × Female | 1.00 | 0.68–1.47 | 0.99 |
Model based on monthly visit counts stratified by age group and sex (month × age group × sex). The dependent variable was the subgroup-specific monthly number of scabies-related visits. Predictors included time, age group, sex, and the age group × sex interaction term.
Figure 2.
Temporal trends in scabies-related visits by sex and age groups. (A) Total visits by sex; (B) Age-stratified trends in males; (C) Age-stratified trends in females.
To assess seasonal variation, an additional negative binomial model incorporating time and season was constructed. Time remained a significant independent predictor of visit counts (IRR = 1.04), indicating that the average upward trend persisted after adjustment for seasonality. Seasonal variation was statistically significant overall. In the adjusted model, only summer differed significantly from winter, with lower ED visit counts in summer (IRR = 0.71, 95% CI 0.56–0.92, p = 0.008), whereas spring and autumn did not differ significantly from winter. Given the 22-month observation period and the lack of two complete seasonal cycles, this finding should be interpreted cautiously and should not be regarded as evidence of a stable seasonal pattern (Table 4).
Table 4.
Negative binomial regression analysis - Seasonal model (n = 10,994).
| Variable | β | SE | IRR | 95% CI for IRR | p |
|---|---|---|---|---|---|
| Time, per month | 0.05 | 0.007 | 1.04 | 1.03–1.07 | <0.001 |
| Winter | — | — | 1.00 | Reference | — |
| Spring vs Winter | −0.10 | 0.12 | 0.90 | 0.71–1.15 | 0.41 |
| Summer vs Winter | −0.34 | 0.13 | 0.71 | 0.56–0.92 | 0.008 |
| Autumn vs Winter | 0.04 | 0.14 | 1.04 | 0.80–1.36 | 0.78 |
A sensitivity analysis restricted to new cases (n = 10,434) yielded consistent findings. Time remained significantly associated with the increase in monthly case counts (IRR = 1.04, 95% CI 1.03–1.06, p < 0.001). These results suggest that the observed ED-based temporal trend was not driven solely by short-term repeat visits.
Discussion
This study showed a statistically significant increase in scabies-related ED visit burden during the 22-month observation period. The high variance-to-mean ratio (55) indicated marked overdispersion in the monthly count data. These findings support the use of negative binomial modeling and are consistent with methodological studies emphasizing the importance of accounting for overdispersion in infectious disease count data [19]. One of the main findings of this study is an average monthly increase of approximately 4% in scabies-related ED visits (IRR = 1.04), which remained significant in both the aggregated time-trend analysis and the subgroup-stratified analyses, and persisted after adjustment for seasonality. This coefficient reflects an average trend over the study period, not a consistent month-to-month increase.
Our findings align with recent international reports of a renewed rise in scabies-related healthcare burden, particularly in high-income settings. In Spain, a retrospective analysis of four national data sources showed increasing incidence from 2011 to 2023, with acceleration after 2020–2021 [12]. Similarly, Dutch primary care and surveillance data demonstrated a marked increase in reported scabies infestations over the last decade, especially among adolescents and young adults [20]. Studies from Belgium have also reported an increasing trend since 2011, with higher incidence in younger age groups, urban areas, and colder months [21]. Earlier UK data further suggested that scabies may follow long epidemic cycles of 15–17 years, indicating that part of the observed increase may reflect cyclical transmission dynamics rather than a purely novel phenomenon [22]. This trend extends beyond Europe: Global Burden of Disease 2021 data showed rising age-standardized scabies rates in high-income regions—including North America—despite an overall global decline since 1990 [23]. Taken together, these findings suggest our ED-based increase reflects a broader international pattern rather than an isolated local phenomenon. However, because our study was single-centre and the denominator-adjusted analysis attenuated the temporal effect, our results should be interpreted as increased ED visit burden rather than direct evidence of population-level incidence.
Sensitivity analyses restricted to initial visits yielded consistent findings, suggesting that the observed ED-based trend was not driven solely by short-term repeat visits. Nevertheless, the monthly time coefficient should be interpreted as the average temporal trend across the 22-month observation period rather than as evidence of a strictly linear or uninterrupted increase. The peak observed in December 2022 indicates that the visit pattern included fluctuations and possible nonlinear behavior. Similarly, the lower number of visits in summer compared with winter is partly consistent with the expectation that increased indoor contact during colder months may facilitate scabies transmission. However, given the short observation period and the absence of concurrent community-level or dermatology outpatient data, the seasonal pattern should be interpreted cautiously.
Various modeling approaches have been used in the literature to evaluate temporal trends in scabies incidence. For example, a time-series study conducted in South Korea incorporated a two-month lag period between infection onset and confirmed diagnosis into the analytical model [13]. In Spain, Joinpoint regression analysis has been used to detect changes in incidence trends over time [12]. In addition, ARIMA models are frequently employed to capture linear trends in surveillance data and to generate short-term forecasts of infectious disease dynamics [24]. In the present study, negative binomial regression was preferred due to the relatively short observation period and the characteristics of the count data. At the global level, scabies remains a significant public health concern. It is estimated that more than 200 million people worldwide are affected by scabies at any given time, and the disease has been classified by the World Health Organization as a neglected tropical disease [11]. Recent studies have reported increasing scabies visit burden across multiple countries, consistent with the upward trend observed in our findings. Seasonal analysis demonstrated a modest but statistically significant effect; however, the overall increasing trend persisted independently of seasonal variation. Previous studies have suggested that scabies cases tend to increase during winter months, likely due to increased indoor contact and crowded living conditions [25]. The relatively modest seasonal effect observed in our study may be related to the short observation period and behavioural changes following the COVID-19 pandemic.
Our findings should be interpreted within a broader international context showing that scabies has reemerged as an important public health problem in both high- and low-resource settings. Across Europe, particularly in the Netherlands, a marked increase in case numbers was observed between 2011 and 2023, with an estimated annual growth rate of 0.25 cases per 1,000 people [26,27]. Data from the United Kingdom indicate that the disease follows an epidemic cycle lasting approximately 15 to 17 years and that these cycles follow a geographical spread, beginning in specific regions [22,28]. These trends demonstrate that scabies is not merely a disease of the past, but rather can spread rapidly among young adults in modern societies, particularly in crowded living environments such as university dormitories. The dynamics of the disease’s spread are directly linked to socioeconomic conditions, migration patterns, and inadequate sanitation facilities. For example, over 178,000 cases were recorded in refugee camps in Bangladesh between 2022 and 2023, highlighting the significant risk posed by overcrowded environments [27]. In addition, seasonal variation has been described in the transmission dynamics of scabies. Dutch data indicate that transmission may peak in July, whereas clinical consultations tend to rise in October and November, likely due to the long serial interval and incubation period. Moreover, the estimated basic reproduction number (R0) of approximately 1.09 suggests that even relatively modest reductions in transmission could support outbreak control when combined with effective public health interventions [26]. It emphasizes that the fight against scabies should not be limited to individual treatment alone, and that public awareness and environmental improvements (WASH—water, sanitation, and hygiene) are of strategic importance [27]. The high burden among adults and school-aged children may indicate increased exposure risk or healthcare utilization in high-contact settings, highlighting the importance of early recognition and systematic contact management in schools, workplaces, and communal environments. Although the relative ED visit frequency was lower among older adults, this population may be more vulnerable to complications and treatment adherence challenges [29]. A slight male predominance was observed in our study, with female visits showing approximately 21% lower relative ED visit frequency compared with male visits.
The observed sex difference may reflect variations in healthcare-seeking behaviour, treatment adherence, or occupational exposure, consistent with reports that gender-related behavioural factors influence treatment compliance in dermatological conditions, which could partially explain the higher visit rates observed among males in our dataset [25,30]. The absence of a statistically significant interaction between age and sex suggests that age-related patterns of scabies-related visits were broadly consistent across both sexes. The observed increase in visits may be explained by multiple factors, including increased social interaction following the easing of pandemic restrictions, delayed healthcare utilization during the COVID-19 period, and changes in socioeconomic conditions. Similar trends have been reported in dermatology-related consultations in Turkey during the pandemic [5,31]. Repeat visits accounted for approximately 5% of all cases, consistent with previous reports. Although treatment resistance was not directly evaluated, emerging evidence suggests that reduced responsiveness to commonly used treatments such as permethrin and ivermectin may occur [32]. Incomplete treatment of close contacts, inadequate environmental decontamination, and poor treatment adherence may contribute to recurrent infestations, underscoring the need for strengthened surveillance, systematic contact management, and adherence-focused education. Molecular epidemiological studies may further help monitor treatment resistance and transmission dynamics [29,32].
Turkish studies have similarly reported increased scabies presentations during and after the pandemic. Atalık et al. reported that the proportion of dermatology outpatients diagnosed with scabies rose from 0.5%–0.9% before the COVID-19 pandemic to 3.1%–4.4% in 2020–2022 [33]. Similarly, Öztaş et al. reported higher post-COVID presentation frequencies, attributing this to lockdown-related household crowding and population movements. These outpatient-level findings, while directionally consistent with our results, should not be interpreted as direct evidence of population incidence [34,35]. Although the seasonal model indicated lower ED visit counts in summer compared with winter, this finding should be interpreted with caution. The study period did not cover two complete calendar years or repeated full seasonal cycles, and ED-based data may also be influenced by healthcare access, care-seeking behaviour, and referral patterns. Therefore, the observed seasonal difference may reflect a combination of transmission dynamics and healthcare utilization patterns rather than a definitive seasonal epidemiological pattern.
The denominator-adjusted sensitivity analysis showed that the temporal increase was attenuated and no longer statistically significant after accounting for monthly green-zone ED attendance, suggesting that changes in overall ED utilization may have contributed to the rise in absolute visit counts. Thus, the findings primarily reflect ED burden rather than population-level scabies incidence. Although the retrospective design limited access to potential socioeconomic and clinical confounders, the study was strengthened by its large sample and use of negative binomial modeling appropriate for overdispersed count data.
Conclusion
This retrospective ED-based trend analysis showed a statistically significant increase in scabies-related emergency department visit burden during the 22-month observation period. The observed trend persisted after adjustment for seasonality and demographic factors, and sensitivity analyses suggested that it was not solely attributable to short-term repeat visits. However, in the denominator-adjusted sensitivity analysis using monthly green-zone ED visits as an offset, the temporal increase was attenuated and was no longer statistically significant. These findings are consistent with the broader concern that scabies may be re-emerging as an important public health issue; however, given the single-centre ED-based design, they should primarily be interpreted as evidence of increased emergency department visit burden rather than as direct evidence of a sustained population-level increase in scabies incidence. Strengthened surveillance, early recognition, systematic contact management, adherence-focused interventions, and environmental control measures may help reduce scabies-related healthcare burden. Further real-world effectiveness studies and molecular epidemiological research may be useful to monitor treatment response, possible reinfestation patterns, and transmission dynamics.
Clinical implications
The observed increase in absolute scabies-related ED visit counts during the post-pandemic observation period highlights the need for continued ED-based surveillance, while denominator-adjusted findings suggest that overall ED utilization should be considered when interpreting temporal trends.
The high burden among adults and school-aged children may indicate increased exposure risk or healthcare utilization in high-contact settings, highlighting the importance of early recognition and systematic contact management in schools, workplaces, and communal environments.
The presence of repeat visits suggests challenges related to treatment adherence, incomplete contact treatment, and possible recurrent infestation, emphasizing the need for strengthened clinical follow-up and public health strategies.
Limitations
This study has several limitations. First, as data came from a single tertiary ED, findings may not generalize to other settings, since many scabies cases are managed in primary care or dermatology clinics; trends should therefore be interpreted as ED visit burden rather than true population incidence.
Second, case identification relied on ICD-10 coding, and although diagnoses were supported by dermatology consultation and dermoscopy when indicated, parasitological confirmation was not available for all cases, so diagnostic misclassification cannot be excluded.
Third, the retrospective design limited access to variables such as socioeconomic status, household crowding, contact history, and treatment adherence/response, and the 22-month period did not span two full seasonal cycles, limiting interpretation of seasonal and longer-term trends.
Finally, repeat visits within 20 days were pragmatically classified as early repeat visits and may reflect persistent symptoms, incomplete contact treatment, or reinfestation rather than confirmed treatment failure or resistance.
Despite these limitations, the large dataset (n = 10,994) and use of an overdispersion-appropriate modeling strategy provide useful evidence on ED-based scabies burden to support surveillance and public health planning.
Acknowledgments
The authors gratefully acknowledge Mrs. Ozlem Koksal for her valuable contributions to the statistical analysis. The article was externally peer-reviewed.
Funding Statement
The author(s) reported there is no funding associated with the work featured in this article.
Ethics approval
This study was approved by the Haseki Training and Research Hospital Clinical Research Ethics Committee (Decision No. 268–2023; December 27, 2023). As this was a retrospective study based on anonymized existing hospital records and involved no direct patient contact, no study-specific written or verbal informed consent was obtained. However, patients had provided general written informed consent for medical care and routine data processing at the time of hospital admission, in accordance with institutional procedures. The study was conducted in accordance with the Declaration of Helsinki and reported following the STROBE guidelines.
Disclosure statement
No potential conflict of interest was reported by the authors.
Data availability statement
The data underlying this study are publicly available in Zenodo at https://doi.org/10.5281/zenodo.19191413. Additional data-related information may be requested from the corresponding author and will be provided upon reasonable request.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The data underlying this study are publicly available in Zenodo at https://doi.org/10.5281/zenodo.19191413. Additional data-related information may be requested from the corresponding author and will be provided upon reasonable request.