Matchbox sign
From Infogalactic: the planetary knowledge core
Matchbox sign is a psychiatric finding. Patients with delusional parasitosis often present at the doctor's office with what MDs term the "matchbox sign",[1] a medical sign characterized by the patient making collections of fibers and other foreign objects supposedly retrieved from the skin.[2] The name refers to the fact that such collections can be stored in matchboxes or other similar small containers, which are then presented to the patient's physician.[1]
