[Delusions of parasitic skin infestation in elderly dermatologic patients].

In a study on 21 patients, who had been treated at the Erlangen Dept. Dermat. for delusion of parasitosis during the last 17 years, we compiled catamnestic data, evaluated the personality profiles, and focussed upon the interrelations between the clinical symptoms, the outcome of various psychological tests, and the course of the disease. Our sociographic results agreed well with those of earlier studies (i.e. social isolation, conflicts in or loss of partnership and sexuality). Nearly half of the patients complained about depressive moods which, however, could not be psychometrically proved. In every fifth patient, we detected a propensity to paranoia both clinically and psychopathometrically, indicating the development into paranoic delusion. In general, the patients' aggressiveness was found rather low. Nor were there any hints for organic psychosyndromes in the majority of the patients. We conclude that delusion of parasitosis usually represents a solitary phenomenon of primary psychosis, which can largely be regarded as a monosymptomatic hypochondriac disorder. Successful treatment with neuroleptic drugs depends on a confidential interrelation between patient and physician.