A 26 year old man presents with diffuse itching over his body. The itching is most prominent over the hands and genitals, is worse at night, and disturbs his sleep. He has noted similar symptoms in his wife and son. He does not have a history of dermatological diseases and his medical history is unremarkable.
Microscopy of scrapings from a burrow demonstrates the Sarcoptes scabiei mite.
No nits or pubic lice are seen
The patch test fails to elicit any form of contact dermatitis
The HIV screening test is negative