Recurrence rate of scabies in patients 14 years or older in Saudi Arabia

To estimate the rate of scabies diagnostic recurrence and identify factors associated with the high likelihood of frequent scabies recurrences among adults in Saudi Arabia.  Methods: This multi-center retrospective study was conducted in adult patients who were diagnosed with one or multiple recurrent infestations of scabies between January 2016 and September 2018 at the Ministry of National Guard-Health Affairs hospitals and clinics, Saudi Arabia. The number of scabies recurrences during the study period was recorded and modeled using a Poisson model. Results: A total of 468 adult patients (39.8±17.8, range: 14.2-105.7 years) were included in the study, resulting in 645 scabies diagnoses in which 302 (46.8%) were recurrences. The multivariate Poisson model revealed that male gender (adjusted rate ratios [aRR]: 1.465; 95% CI: 1.064 - 2.017; p=0.019), first tertile (January to April) (aRR: 3.021; 95% CI: 1.484 - 6.149; p=0.002), and high humidity (aRR: 1.066; 95% CI: 1.002 - 1.133; p=0.043) had a higher likelihood of frequent scabies recurrences. Conclusion: The rate of scabies recurrence among adult patients in Saudi Arabia was high, and is comparable with previous report in Japan. The study suggests that male gender, first tertile, and high humidity were independently associated with the high rate of scabies recurrences among adults. An interventional program to lower the rate of scabies recurrences and prevent outbreak should be undertaken.