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Who to talk to when you have insects on your mind
Prof Martin Villet,
Rhodes University, South Africa
 Insects
- one subject that brings together science, the law and mental health. For the
uninitiated, forensic entomology is now an established science, where scientists
are able to, for example, retrieve maggots from murder victims to estimate when,
and possibly where, the victim died. Forensic entomologists have also found
themselves testifying in cases involving insect damage to stored goods. Such
damage by insects can be expensive and worth taking to court. But one of the
lesser known tasks of a forensic entomologist involves psychiatric conditions
which are focused on insects. For some, it turns out, insects, real or imagined,
do more than just make your skin crawl. Prof Martin Villet provides insight into
an often debilitating set of illnesses.
Insects profoundly influence human lives, including our language, arts,
history and religion, and it is no surprise that they are also associated with
certain psychiatric disorders. They can be broadly classified into phobias,
illusions and delusions. Medically, it is important to separate these disorders
from each other and from other conditions with similar symptoms because they
require different forms of help and treatment. In some cases, the sufferer may
be so unwell that they have to be institutionalised, and that is one place where
the law may enter the picture.
Entomophobia, the irrational fear of insects
 There
are rational reasons to be wary of some insects, such as mosquitoes, bees and
wasps, and some people simply don't like other insects because of their looks or
habits. We may even be wary simply because we don't know enough about the insect
to know if it is harmless or not. These are not cases of phobia.
However, some people have persistent, irrational fears of insects and these
fears cause them significant distress even though they know that they are
unreasonable or excessive feelings. What is important here is that the condition
is triggered by the presence of real insects, and it is usually experienced by a
single individual.
In clinical cases of entomophobia, as in other phobias, the more likely cause
is a displacement of non-specific anxiety to an external focus that can then be
avoided. The choice of insects as the external focus may be random, symbolic, or
even perfectly logical. When it is symbolic, the insects often represent filth
and uncleanness. An example of the "logical" choice of insects as a
phobic focus involves the case of a very young girl whose sister died of
pneumonia. The child developed entomophobia after being told that her sister had
died from a 'bug'.
Individual cases of entomophobia can have unusual consequences, such as that
of a man who obsessively killed every spider around his house and garden. Having
decimated this population of predators, his vegetable patch was overrun with
pests.
The task of the forensic entomologist in cases of phobia is primarily to
confirm that there is an insect involved, and to reassure sufferers about the
harmlessness of the insects. The actual phobia is best treated by qualified
psychiatric or psychological counsellors. Entomophobia rarely ever involves the
law, but if a patient is misdiagnosed, they may sue the erring party.
Illusory Parasitosis, illusions arising from real environmental stimuli
Unlike phobias, illusory parasitosis is not a true psychiatric or
neurological disorder, but a physical condition. The sufferers experience real
rashes and other irritations, which they attribute to parasitic insect bites or
stings. What is diagnostic here is that no insects can be found that could cause
the symptoms, and that these symptoms are generally shared by a group of people
who work or live in the same place. Fumigation of 'infested' places does not
bring relief. The symptoms usually vanish when the sufferer moves to a different
environment. Morale issues may complicate the situation, especially if working
conditions in the shared environment are dull, uncomfortable or stressful.
The real culprits in illusory parasitosis are often chemical fumes or fibres
in the environment, such as asbestos from insulation, paper fibres and chemicals
from photocopiers, or other material blown through air-conditioning systems.
This explains why fumigating is no help in these cases, and why it affects
several people sharing an environment. The condition was first examined
seriously in the 1960's when a few cases of mass parasitosis in offices and
laboratories were ascribed to non-existent "cable mites" and
"paper lice". The "cable mites" were in fact asbestos fibres
carried through the air-vents of a laboratory. Today, such a case of
misdiagnosis, for example by fraudulent pest control operators, would certainly
lead to lawsuits that could involve a forensic entomologist.
Here, the role of the forensic entomologist is to verify whether there are
insects or mites present. Since mites are very small, this investigation should
be carried out very carefully. If no insects or mites are found, a competent
industrial epidemiologist should be brought in to diagnose what is essentially a
form of 'sick building syndrome'. Once the cause is traced, the illusions should
vanish.
Delusory Parasitosis, delusions arising from psychiatric or neurological
conditions
Like illusory parasitosis, there are no actual insects involved in cases of
delusory parasitosis. Sometimes called Ekbom's Syndrome, the condition involves
a sufferer experiencing an unshakable but false belief that there are parasites
living in or on their skin. Diligent searching reveals no parasites, and yet the
sufferer can describe their shape, size, colouration, movements and behaviour in
detail. They often produce matchboxes or pill bottles with fluff, splinters and
other debris that they insist are specimens that they have caught.
What is diagnostic in these cases is that there are no insects, and that the
condition is not alleviated by moving to another environment. Usually only one
person has the symptoms, although couples may trigger off one another through
their scratching; sufferers frequently scratch themselves raw trying to remove
the itches they feel. They may become extremely upset that no one believes them,
and they may get increasingly desperate in their attempts to eradicate the
'pests', including washing in dog shampoo or even pesticides. Cases have even
ended in suicide.
Delusory parasitosis has been classified into two forms, depending on its
causes. Secondary delusory parasitosis may be associated with neurological
conditions like delirium tremens, diabetes, TB, syphilis, pellagra and other
tactile sensory disorders, where the underlying disease produces sensations of
insects walking on the skin, which is termed 'formication'. Treating the primary
disease may lead to a remission of the delusion. Primary delusory parasitosis is
a psychological condition where the delusions are the sole symptom, and the
prognosis here is less optimistic. There is no generally accepted method of
treating primary delusory parasitosis, although there are a variety of
approaches.
Forensic entomologists may be called in to verify or challenge a medical
diagnosis, perhaps in court, for example in cases where a person with primary
delusory parasitosis needs to be committed for care. Sometimes a sufferer is
genuinely infested, usually with microscopic burrowing mites like
Dermatophagoides schermetewskyi Bogdanow that is not easily detected by routine
medical inspection. As with entomophobia and illusory parasitosis, the forensic
entomologist's role is to provide expert opinion about the presence and identity
of insects and their relatives, and not to diagnose psychological conditions.
So, one can see that forensic entomologists come across a wide spectrum of
cases besides what is commonly shown on television. It is this variety that
makes the job more interesting, and adds a dimension that most people would not
suspect existed.
Next month, read another focus on forensic entomology at Science in Africa.
More information:
October 10 2003 is World Mental Health day.
World Federation for Mental Health www.wmhday.net
Related articles:
Your child's mental health - asking the questions
World mental health day 2003 focuses on adolescents
and children
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