Association Between Total Serum Immunoglobulin E Levels and Persistent Pruritus Following Scabies Treatment: An Observational Study

BACKGROUND: Scabies is a common parasitic skin infestation associated with significant immune activation. Elevated total serum immunoglobulin E (IgE) levels have been reported in scabies; however, their association with persistent pruritus following treatment remains unclear. METHODS: This observational analytical study with follow-up assessment included 66 subjects (30 scabies, 36 non-scabies) recruited from Sardjito General Hospital, affiliated hospitals (Sleman Regional General Hospital), and boarding schools in Yogyakarta, Indonesia. Scabies was diagnosed using the 2020 International Alliance for the Control of Scabies (IACS) criteria. Total serum IgE levels were measured once at baseline using electrochemiluminescence immunoassay. Pruritus severity was assessed using the Visual Analogue Scale (VAS) at weeks 0, 2, 4, and 8 following treatment with topical permethrin 5% cream with a repeat application after one week according to standard treatment recommendations. Non-normally distributed data were summarized using median and interquartile range (IQR). Statistical analysis was performed using the Mann-Whitney U test and Spearman correlation. RESULTS: The scabies group demonstrated significantly higher total serum IgE levels compared to the non-scabies group (median 570.80 IU/mL (IQR 100.36-5179.00) vs. 36.57 IU/mL (IQR 2.92-193.00); p < 0.001). Baseline total serum IgE levels showed a strong positive correlation with pruritus severity at week eight following treatment (ρ = 0.777; p < 0.001). CONCLUSION: Total serum IgE levels were significantly higher in patients with scabies and were associated with persistent pruritus after treatment. These findings suggest a possible link between systemic immune activation and ongoing symptoms. However, due to the observational study design, causal inference cannot be made, and the lack of parasitological confirmation of mite eradication should be considered when interpreting these results.