The body distribution of scabies skin lesions

Abstract

Background

The clinical diagnosis of scabies relies on the assessment of signs and symptoms and an improved understanding of the distribution of skin lesions may lead to improved diagnostic performance.

Objectives

To investigate the detailed body distribution of scabies lesions and to explore the accuracy of simplified, focused examination approaches.

Methods

We did a prospective, cross‐sectional study in the Western Province of Solomon Islands (2019). Consenting individuals of all ages were eligible. The entire skin surface was examined, and the presence and number of typical scabies lesions were recorded at 98 topographic body sites, corresponding to 5 regions and 16 subregions. We compared the distribution at sites, regions and subregions overall, and by age and sex. We also calculated the expected sensitivity of examination of limited body areas. Choropleth maps were generated to provide detailed descriptions of the distribution of lesions.

Results

A total of 467 individuals were enrolled (median age: 9 years [range: 0–86]; female: 54.6%) of whom 269 (57.6%) participants had typical scabies lesions. The most common sites for scabies lesions were the dorsal fingers (65.7% of participants with scabies lesions), dorsal finger web spaces (62.1%) and dorsal hands (61.7%). Of those less than 2 years old with scabies, eight (30.8%) had lesions at the head and neck region compared to 10.8% of those aged 2–5. Genital lesions were more common in males than females (27.3% vs. 7%, relative risk 3.9, 95% confidence interval: 1.2–2.1). Simplified, focused examinations were estimated have very high sensitivity (hands and wrists only: 93.3%; exposed arms and legs: 99.3%) compared to whole‐body examinations.

Conclusion

We report highly detailed descriptions of the body distribution of scabies lesions, including differences by age and sex. These data are valuable for training and diagnosis and support the use of simplified, focused examinations for scabies mapping.