Delusions of parasitosis (DOP), also known as “delusional infestations,” “acarophobia,” “Ekbom syndrome” and “Morgellons,” is classified as a primary psychiatric disorder. The pathology of primary psychiatric disorders, including DOP, is psychological. This means that the patient has no primary skin pathology, and all skin findings are secondary to skin manipulation by the patient.
Psychosis is defined by the presence of a delusion. The most common type of psychotic patient that dermatologists treat has monosymptomatic hypochondriacal psychosis (MHP). MHP is characterized by a delusional ideation that focuses on one hypochondriacal concern.[1
] DOP is the most common type of MHP seen by dermatologists. In fact, up to 90% of patients with this condition are seen by dermatologists.[4
] Except for the presence of an “encapsulated” delusional ideation, patients with MHP usually appear appropriate in other capacities. It is often the case that MHP patients have hallucinatory experiences compatible with their specific delusion. For example, for patients with DOP, many experience formication, which is manifested as cutaneous sensations of crawling, biting and stinging. In addition, DOP patients experience a significant decline in quality of life, including decreased work productivity or job loss, disability and social isolation.[5
As a result of the high percentage of DOP patients seeking help from dermatologists, it is important for those in our profession to be equipped with the expertise needed to accurately identify and treat this special patient population. In this concise review, we will cover the epidemiology, presentation, differential diagnosis and treatment strategies for patients with DOP.