Does My Sister Have Delusional Parasitosis — Or Some Other Serious Disorder?

Reader’s Question

I have a sister who just recently moved into my house because she is broke. My family and I had not seen her in 3 years until she sent us an email saying that she wanted a “private” life and to be left alone. I believe she is suffering from some sort of delusional beliefs. From what I have read, I think she is suffering from delusion of parasitosis. She washes her hair/showers twice a day (45 minute long shower each time), washes her bedding daily, engages in hours of bathroom rituals, and claims that she is being bitten by lice. We see no bite marks. My kids have no lice. Additionally, she claims her family is trying to influence her and control her life. She writes long emails accusing her family of interfering, imposing, and harassing her. She talks about various kinds of persecution and themes of submission, etc. She repeatedly refers to “God the Father,” and other religious sayings. Now, we are afraid to even talk to her because of the tirades she sometimes goes on. Today, she sent out a long email accusing us of using my four-year-old daughter as an instrument for controlling and insulting her.

I can’t find anything on the Internet about how to approach her and get her to agree to seek professional help. How do I even start a conversation about this? Is this something I need to do by myself or should we as a family confront her? How do I get her to even listen when her “irrational” fear seems to center around being controlled? I don’t want her to be so upset that she leaves and ends up living under a bridge somewhere.

Our Clinical Psychologist’s Reply

Delusional Parasitosis is a specific false belief that parasites are infesting the body, most commonly crawling upon or burrowing under the skin. It can exist as a freestanding disorder, in which case no other delusions are present and no other mental functioning is compromised. It can also occur as a secondary symptom of a major mental illness such as schizophrenia or a psychotic level of depression. Still yet, it can occur along with other delusional states as a the result of an underlying medical condition. So, in order to pin down the diagnosis accurately, a full medical and/or psychiatric evaluation is necessary.

If your sister is a legal adult and is not posing an acute danger to herself or others, it’s often difficult to force the issue of treatment. Some jurisdictions allow for the temporary confinement of mentally ill individuals for evaluation and treatment after concerned family members meet certain requirements even if there is no clear, immediate threat of homicide/suicide. Advocacy and support groups (such as the National Alliance on Mental Illness in the U.S.) can often be a great resource for helping families wade through the complexities of dealing with these types of problems. Your family doctor can also be a valuable resource.

Sometimes the best approach in seeking help is to encourage the afflicted person to at least visit with a doctor to address the concerns they’ve been expressing. This can be done without confronting delusions directly. Rather, a person might suggest that because of the dangers to their health that their reported problems (delusions) could cause, it would be a good idea to get a “checkup.” Getting a foot in the door, so to speak, with regard to treatment is the hardest but the most necessary first step.