Matchbox sign

The matchbox sign, also referred to as the Ziploc bag sign or the specimen sign, is a psychiatric finding. Patients with delusional parasitosis (DP) often arrive at the doctor's office with this medical sign. People with DP can damage their skin by attempting to remove imaginary parasites via chemical substances or obsessive cleansing. The individual typically collects items extracted from the skin, and stores them in a matchbox or similar small container, to present to the physician as proof of a parasitic infestation. These items may include scabs and skin particles, dust and dirt, and plant or animal fibers, and may be accompanied by photographs. Laboratory analysis fails to find proof of parasitic infestation. The matchbox sign is present in five to eight out of every ten people with DP.
History.
The matchbox was described by Lyell (1983) as the most common container used to present specimens to the physician.
Shelomi (2013) published a study of what he called scientific misconduct when a 2004 article in the "Journal of the New York Entomological Society" included what he says is photo manipulation of a matchbox specimen to support the claim that individuals with DP are infested with collembola.