Scabies increased the risk and severity of COPD: a nationwide population-based study

Background: Scabies is a common parasitic infectious disease, and COPD is a major pulmonary disease. However, there have been no previous studies that have investigated the relationship between scabies and COPD. Materials and methods: This nationwide population-based study included a total of 3,568 patients with scabies as the study group and 14,255 patients as a control group. We followed up patients in both groups for a 5-year period to identify any new diagnoses of COPD. We then followed them up for an additional 2-year period to determine the severity of any newly diagnosed cases of COPD as indicated by acute respiratory events. Cox proportional hazard regression analyses were performed to calculate the hazard ratio (HR) of COPD during the 5-year follow-up period and COPD complication during the additional 2-year follow-up period. Results: Of the 17,823 patients in the study, 2,765 (15.5%) were newly diagnosed with COPD during the 5-year follow-up period; 904 (32.7%) were from the scabies group; and 1,861 (67.3%) were from the control group. Compared to the patients without scabies, the adjusted HR (aHR) for COPD for the subjects with scabies was 1.72 (95% CI: 1.59-1.87) during the 5-year follow-up period. For those newly diagnosed with COPD, the aHR for COPD with acute exacerbation was 1.85 (95% CI: 1.67-2.06), the aHR for COPD with pneumonia was 3.29 (95% CI: 2.77-3.92), the aHR for COPD with acute respiratory failure was 4.00 (95% CI: 3.08-5.19), and the aHR for COPD with cardiopulmonary arrest was 3.95 (95% CI: 2.25-6.95) during the additional 2-year follow-up period. Conclusion: The results of this study indicate a 72% increased risk for COPD among patients with scabies. The results also reveal an increased risk of severe COPD complications such as acute respiratory failure, cardiopulmonary arrest, pneumonia, and acute exacerbation among patients with scabies. This useful information may help physicians in treating scabies and remaining alert to the potential development of COPD and its severe complications.