Patients with difficult conditions such as delusional parasitosis tend to resist the notion that a psychiatric problem underlies their symptoms.
Some diagnoses can be difficult to recognize, but timely diagnosis and psychiatric treatment, as well as patient education and effective communication, can improve quality of life and reduce medical costs. Consider this case of delusional parisitosis.
Patients with delusional parasitosis have a characteristically rigid belief in their perceived infestation that often leads to involvement of nonpsychiatric health care professionals. However, listening is the first step in discovering the root of the problem.
Depressive symptoms emerged 2 years before the current presentation. The depression had been effectively controlled for a year and finally remitted a year ago with citalopram.
Patients have reported parasites crawling, living, and breeding under his or her skin for several months and have sought help from various sources.
Self-induced dermatological findings can result from attempts to remove the parasites. Samples of skin or other debris from the “parasites” are provided (stereotypically in a matchbox, leading to many referring to this as the “matchbox sign."
The diagnostic process and prognosis can be improved if delusional parasitosis is included in the differential.
This patient previously visited her primary care physician as well as a dermatologist, a cardiologist, and 2 emergency departments to seek treatment for these complaints.
Another technique for improving a patient’s acceptance of a psychiatric diagnosis such as delusional parasitosis is to be sympathetic. Mrs Dalton initially dismissed the assertion that her parasites were in fact not physically present. She became more accepting of having a mental health condition and of the need for psychiatric follow-up after much empathic discussion.
Mrs Dalton reports that no treatments have improved her condition.
Patients with delusional parasitosis are commonly anchored by treatment with antipsychotics. In the past, pimozide was the antipsychotic of choice for this disorder. However, recent studies have favored atypical antipsychotics, such as risperidone and olanzapine, because of their favorable adverse-effect profiles compared with older treatments.
Mrs Dalton is started on a regimen 1 mg of risperidone nightly. There are no adverse effects to the medication while she is hospitalized. She is discharged with plans to follow up with the psychiatry service. She is provided psychotherapy and medication management during subsequent appointments. Within a few weeks, significant improvement is seen in the frequency and severity of the symptoms with these treatments. Almost all treatment recommendations include regular psychiatric follow-up for medication management and psychotherapy.
Careful counseling can ease a patient’s understanding and acceptance of parasitosis. It is important to acknowledge the seriousness of the patient’s complaints and to complete a thorough physical examination to help alleviate feelings of being dismissed as “crazy.” Additional techniques for improving a patient’s acceptance of a psychiatric diagnosis include listening patiently to complaints about symptoms, acknowledging that the symptoms are “real” without challenging or validating theories about the cause of the symptoms, expressing empathy, and carefully examining samples of “parasites” that the patient provides.