Matchbox Sign of Delusional Parasitosis

 

The matchbox sign refers to the patient:

(1) bringing in a container filled with skin fragments or small pieces of debris often recovered while scratching

(2) complaining of pruritus

(3) claiming that the bits and pieces are evidence of a parastic infection

(4) no evidence of a parasite or pathogenic insect in the material

 

The container may be:

(1) a matchbox

(2) an envelope

(3) a pill vial

 

Additional features:

(1) The patient may become enraged when the belief is not accepted.

(2) The patient may present to multiple clinicians with the same or similar containers.