When customers' delusions affect their pets

Long-time readers of this blog, or you who hear me talk at pest control conferences, know that I occasionally address the subject of delusions of parasitosis.  This is one of the trickier "pest" problems to solve, especially since there is no pest involved.  In my office I receive 2-3 suspected delusional samples per month, many as referrals from some of you.  The problem seems worse this year, as I have had many people convinced that they have intractable biting mite problems after reading misleading and harmful information online.

A recent article published in the Veterinary Information Network News Services addressed the issue of pet owners bringing their pets in for treatment of non-existent bugs. Apparently PMPs and vets both have to deal with this issue, and I found the article informative and helpful. One story, highlighted in the accompanying photo, had a happy ending when the client accepted psychiatric treatment. Sadly, it is very difficult to get most delusional clientele to pursue such therapy.

Some of these folks perceive normal grooming behavior of their pets as proof that the pet is infested and suffering. I guess the lesson here is that in cases where you cannot detect a valid pest, and the pest description doesn't match reality, take everything a customer claims with a grain of salt.  For more information on diagnosing mysterious bug bite cases see my factsheet.

Morgellon's syndrome and delusions of parasitosis

Typical sample from client with non-existent bugs.

A few years ago they came in matchboxes.  Today they're more likely to come in pill jars, Ziploc bags or on pieces of Scotch tape.  I'm talking about samples of nearly invisible items that clients believe are biting or crawling over their skin.  Though it's true that there are some tiny insects and mites that can bite or parasitize people, more frequently these samples turn out to consist only of lint or skin scrapings or insects that would never bite a human.

Most urban entomologists or pest management professionals who have been in the business long enough  know what I'm talking about. There are a surprising number of people seeking help from PMPs or entomologists, convinced that they are being bitten by non-existent bugs.  Some of these unfortunate clients suffer from an allergy, environmental sensitivity, medical condition or drug reaction that resembles a creeping or pricking sensation on the skin.  These good folks have a real medical condition, but are falsely persuaded that insects or mites are involved.

Other clientele are likely suffering from what doctors call a dermatopsychiatric condition, or somatic delusion--technical jargon for a mental illness that causes someone to believe and feel infested by bugs or other animate or inanimate objects.  The problem is common enough to have a name, "Ekbom's syndrome" or "delusions of parasitosis".

I don't know what percentage of the people I encounter each year are (in cases of physical conditions) illusional versus (cases of mental illness) delusional; but I have become convinced based on a variety of similarities and resistance to diagnosis that a high percentage fall into the latter group.

A diagnosis of delusional parasitosis is always resisted and often resented by sufferers. No one wants to hear that a very large problem in their life is psychosomatic.  Indeed the psychological definition of a delusion is "an unshakable belief that cannot be corrected by reason or logic, and which is inconsistent with a patients' intelligence, education or cultural background."  Even family members often find it hard to accept that their loved ones are suffering from a psychosomatic problem.

A paper published earlier this week by Sara Hylwa and colleagues at the Mayo Clinic in Rochester, MN represents one of the first published efforts to take a serious and critical look at specimens and skin samples from people who had been diagnosed with delusions of parasitosis.  A total of 108 patients previously diagnosed as delusional were included in the study. None of the 80 skin biopsies from these patients provided any evidence of skin infestations of any sort (including scabies).  Ten actual insect specimens provided b patients were assessed and 9 out of the 10 were determined to pose no risk of skin infestation (one was a pubic louse).  Most of the samples consisted of skin debris, environmental detritus, or plant material.

These findings are consistent with what I have observed for over 20 years as an extension entomologist.  During this time I have looked at perhaps 2 to 3 samples a month that turn out to not be insects. Encountering a delusional client is frustrating because, as an entomologist I can often recognize the problem; but there is little I can do to treat or solve it, short of educating caregivers. 

The Mayo study represents the first of two highly anticipated reports on this problem by medical researchers.  A second study is due out in a few months.  According to an article by Melissa Healy in the L.A. Times, this second study, being conducted by the Centers for Disease Control and Prevention working with Kaiser Permanente of Northern California, was launched in January 2008 after patients and a small group of medical professionals led by an organization called the Morgellons Research Foundation advocated for a full-scale government investigation of their symptoms.

The Morgellons Foundation was formed by an online community of people resistant to the suggestion that biting problems can be psychosomatic.  They believe that there is a third possible explanation for cases where bugs can't be found--some mysterious underlying condition that causes the suffering of many or most people today being diagnosed as delusional.

I would, in some ways, be relieved to find out that there really is some organic cause for the suffering I see in many of the people who pass through our office doors each year. It would allow me to give such clients and their families hope that there's a non-psychological explanation for their torments.

I'm not overly optimistic, however. Mental illness is consistent with the irrational and compulsive behavior often exhibited by the bearers of empty matchboxes and Ziploc bags.  Often these folks will provide contradictory and illogical descriptions of their problems.  And the compulsive self-treatment, discarding of furniture, and extreme behavior to escape their insect pursuers is not normal or healthy.

As a PMP there are a few things you can do. 

• If the client cannot produce a likely specimen, use sticky cards around the home. Give the cards a week or so to trap anything suspicious. 
• Check the premises for signs of rodent or bird infestations.  Mites associated with bird and rodent nests can bite people, though they will not hitchhike or live on humans.
• Keep an open mind and take complaints seriously, but don't be pushed into making applications of pesticides that you cannot justify.
• Encourage the cliente to seek a medical opinion, pointing out that sensations of biting or creeping can be caused by things other than arthropods.  Be sure to include a family member or caregiver in the conversation if you can.
• Don't diagnose someone as delusional.  That's a judgment that can only be made by a health professional.  You are, however, knowledgeable about insects--likely more than the average doctor.  Stick to what you know.
• Don't forget to make use of third-party information when communicating with the client or with family members.  I have written a factsheet on Diagnosing Mysterious "Bug Bites" for this purpose.  Beware of information gleaned from dubious sources on the Internet--there is a lot of false and misleading information on this subject online.