Folie a Famille: delusional parasitosis affecting all the members of a family.

Delusional parasitosis (Ekbom syndrome) is an uncommon psychiatric disorder that presents with a delusion of being infested with parasites. Treatment of this condition is difficult as patients with this paranoid disorder reject psychiatric diagnosis and treatment and often consult a dermatologist. Sharing the delusional beliefs of the paranoid patient by other people living in close emotional bonding with him/her could occur. We report here the clinically interesting phenomenon of delusion of parasitosis occurring simultaneously in all the members of a family. There was a pathological bonding between the members of the family who all presented to the dermatologist and rejected treatment. Dermatologists need to be aware of this uncommon clinical picture.