Abstract Number: 251

A novel way to display lesion distribution: describing the location of scabies lesions using choropleth mapping

M. Osti2,1, S. Dauer2,1, O. Sokana3, M. Whitfeld4, M. Marks5, A. Steer2,1, D. Engelman2,1,6

Meeting: 2021 Dermcoll

Session Information

Date: -

Session Title: Poster Presentations

Session Time: -

Lesion distribution may inform diagnosis, especially when diagnosis is dependent on clinical suspicion and assess- ment of presenting features. For public health decision- making, assessment is often limited to exposed skin areas due to privacy concerns or time constraints. This study aims to identify the distribution of scabies lesions and determine if examination of exposed areas is sufficient for diagnosis. We also introduce a novel way to display lesion distribution data.

We conducted a prospective, cross-sectional study in the Western Province of the Solomon Islands. Individuals of all ages, with and without scabies were enrolled. An experi- enced doctor examined participants and recorded the pres- ence of scabies lesions in 98 clinically relevant cutaneous body regions. Choropleth maps were produced using a sequential colour palette, displaying the proportion of par- ticipants with lesions in each of the 98 sites. Exposed sites were considered those which can be easily examined with- out the removal of clothing.

499 individuals were enrolled, with a median age of 9 (range 0–86); 56% were female and 59% had clinical sca- bies. The hands were the most common sites for scabies lesions (dorsal fingers 65%, dorsa of hands 61%, finger webspaces 61%). The buttocks (40%) and dorsa of the feet (38%) were also common sites. Only 2% of those with sca- bies had lesions at only unexposed sites.

This study identifies clinically relevant sites of lesions and provides evidence for a simplified examination of only exposed areas. This study also demonstrates that choro- pleth mapping is a useful approach for the display of lesion distribution.