Risk Factors and Lesion Patterns in Treatment-Resistant Scabies: Impact of Sex, Age, and Comorbidities

Abstract

Purpose

Scabies is a common parasitic skin condition with significant morbidity. This study aimed to identify risk factors for treatment failure and analyze lesion distribution patterns in relation to sex, age, and comorbidities in patients with treatment-resistant scabies.

Methods

The study included patients with dermatologist-confirmed scabies who had received at least one treatment within the past six months without clinical improvement. Clinical, sociodemographic, and cutaneous findings were evaluated.

Results

A total of 246 patients were included (130 females, 52.8%; 116 males, 47.2%). Males had significantly higher rates of excoriation (p < 0.001), pustules (p = 0.047), tunnels (p = 0.046), and genital involvement (p = 0.012). Nodules were more common in individuals under 18 (p = 0.003), while excoriations predominated in those over 65 (p < 0.001). Longer pruritus duration was observed in older adults, rural residents, and patients receiving weekend home visits (p = 0.017, p < 0.001, and p = 0.011, respectively), and was associated with increased lesion severity. A threefold increase in abdominal involvement and a 3.33-fold increase in pustules were seen in patients receiving three or more treatments. Higher education (university or above) was linked to a 46% reduced risk of treatment-resistant scabies.

Conclusions

This study identifies key demographic and clinical risk factors associated with treatment failure in scabies and underscores the need for targeted management strategies. To the best of our knowledge, it is the first to comprehensively investigate lesion distribution and clinical patterns of resistant scabies in relation to sex, age, and comorbid conditions.