Matchbox sign

The matchbox sign, also referred to as the Ziploc bag sign or the specimen sign, is a psychiatric medical sign in which a patient arrives at a doctor's office with items extracted from the skin; these items are intended to serve as proof of a parasitic infestation, and are typically stored in a small container such as a matchbox.[1][2] 50–80% of patients with delusional parasitosis present with this sign.[3]

People with delusional parasitosis can damage their skin by attempting to remove imaginary parasites. These items may include scabs and skin particles, dust and dirt, and plant or animal fibers, and may be accompanied by photographs.[4] Laboratory analysis fails to find proof of parasitic infestation.[1]

  1. ^ a b Reich A, Kwiatkowska D, Pacan P (December 2019). "Delusions of parasitosis: an update". Dermatol Ther (Heidelb) (Review). 9 (4): 631–638. doi:10.1007/s13555-019-00324-3. PMC 6828902. PMID 31520344.
  2. ^ Koo J, Lebwohl A (December 2001). "Psycho dermatology: the mind and skin connection". Am Fam Physician. 64 (11): 1873–1878. PMID 11764865.
  3. ^ Moriarty N, Alam M, Kalus A, O'Connor K (December 2019). "Current understanding and approach to delusional infestation". Am. J. Med. (Review). 132 (12): 1401–1409. doi:10.1016/j.amjmed.2019.06.017. PMID 31295443. S2CID 195893551.
  4. ^ Campbell EH, Elston DM, Hawthorne JD, Beckert DR (May 2019). "Diagnosis and management of delusional parasitosis". J. Am. Acad. Dermatol. (Review). 80 (5): 1428–1434. doi:10.1016/j.jaad.2018.12.012. PMID 30543832. S2CID 56483906.