thin / to lose weight / (of clothing) tight / (of meat) lean / (of land) unproductive
瘦
=
叟
+
疒
:
Sherlock Holmes (sh) and the old gentleman (叟) have been locked into the outhouse's bathroom (ou4) to be in quarantine for the very colorful rash (疒) they developed. Because of their sickness they already lost a lot of body weight and are very thin (瘦).