When Nothing Bites – Delusionary Parasitosis

As pest control professionals, we are often confronted with bug bites and asked to determine which bug has caused the bite. Nine times out of ten, we identify the bug bite, confirm our suspicion with an insect ID, and treat the pest, providing instant relief to the bug bite sufferer. Occasionally, despite insistent complaints of bug bites, no bugs are found. Often, people who insist they are being bit by bugs are shuffled between medical doctors including dermatologists and psychiatrists, and pest management professionals. When this itching, scratching, and irritating sensation persists, despite no insects being found, it is termed delusionary parasitosis.

Delusionary parasitosis is an imperfect term. The medical profession defines delusion as an unshakeable or fixed belief that something is true despite evidence to the contrary. Parasitosis simply means an infestation of parasites. Therefore, the hallmark characteristic of delusionary parasitosis is the unshakeable belief that a person is being bitten by microscopic or tiny insects or parasites. The fact that no insects or parasites being found does not discount the fact that the itching, burrowing, or crawling sensations may in fact be a real physical condition that needs remedied. Many times, there are perfectly valid reasons for the physical sensations that are being experienced; it is simply not entomological in nature.

Common Characteristics of Delusionary Parasitosis

Patients afflicted with delusionary parasitosis often complain of paresthesia, which is the sensation that their skin is being walked on, pricked, or a general tingling feeling of the skin. They may complain of itchy skin which may intensify at night, and the belief or feeling that they are being bitten by an unseen adversary. With these sensations, they begin to scratch at themselves and cause physical wounds or cuts from aggressive scratching.

Delusionary parasitosis is most commonly found in older women. As the feeling persists, many sufferers take extreme measures to alleviate the problem, which they steadfastly believe to be related to insects or bugs. They may throw out furniture or beds, obsessively launder and clean, or use pesticides in dangerous and unlabeled manners. When repeated use of pesticides throughout the home do not alleviate the itch, they often resort to dangerous home remedies, such as applying gasoline, bleach, essential oils, and other harsh chemicals to “kill the bugs.” They often repeatedly provide samples of what is biting them only to be told, they have captured lint, dust, and dirt. Sadly, people often suffer for years, usually seeing many doctors and speaking to many pest management professionals with no relief.

Delusionary parasitosis is a serious disorder which significantly impairs the patient’s ability to function. In extreme cases, they may abandon their home or job hoping the bugs will not follow them. They often suffer from social isolation and damaged personal relationships. They are often resistant to psychiatric treatment, instead insisting that small insects are the source of their torment.

Causes of Delusionary Parasitosis

Delusionary parasitosis simply explains the belief that insects or parasites are to blame for the uncomfortable nature of the subject’s skin. Despite the flaw in the rationale, their skin is undoubtedly uncomfortable. There are a host of reasons why a person may experience the physical symptoms that are being complained of.

Physical Causes of Delusionary Parasitosis

When skin discomfort is initially felt, it is human nature to scratch. If scratching is persistent, you can break the skin and perpetuate the intense discomfort. Infection may settle into the wound and hairs and cloth fibers may become entrapped in scabs or crusty fluid. These situations may resemble antennae of insects, furthering the belief that bugs are the root of the problem.

As this disorder continues, harsh chemicals and/or pesticides are often placed in large quantities on the skin. This will further skin discomfort, irritation, and redness. In addition, skin irritants such as fiberglass, insulation, and other building materials could be causing the feelings experienced. Skin sensitivities can change as we age, and dry sensitive skin is at particular risk of these phenomena. Using different or more frequent laundry detergents, fabric softeners, and household cleaners can also cause these items to build up on bed linens and upholstery potentially irritating the skin. This causes more irritation and triggers a response to “treat again” and re-launder linens. The cycle gets worse and worse each time. Besides changing detergents or fabric softeners, we have seen customers who have purchased new sheet sets, typically very cheap low quality sets, which further causes skin irritation. Miraculously, after weeks of issues, the situation is resolved when they switch back to their old sheets set. Look closely at any recent changes in linens, furniture, detergents, or cleaners as possible causes.

Some experts believe that static electricity explains some of the feelings and observations of those tormented by delusionary parasitosis. The static electricity generated by computer equipment may cause particles to stick to legs or hands. In addition, people claim to see flying insects when what they actually observe is dust floating in the sunlight drenched window.

Possible Medical Causes of Delusionary Parasitosis

In today’s fast paced medical environment, deep dives into complicated or unusual symptom are rare. However, the feeling of being pricked, bitten, or being crawled upon could be a result of allergies, nutritional deficiencies, drug reactions, or another medical diagnosis. Numerous medical conditions and prescription drugs list itching and skin irritation as a possible side effect. Many commonly prescribed medications are known to cause “biting sensations” as a side effect. An allergic reaction to laundry detergent, soap, lotion, or shampoo may provide a logical explanation for the skin sensations experienced.

If you or a loved one are experiencing unexplained skin irritations, take a close look at your medications and any possible drug interactions. Many drugs, particularly those prescribed to the elderly, list skin issues as a possible side effect. For example, the fifth most prescribed medication Prozac, include 5 possible side effects commonly attributed to delusionary parasitosis. Make sure to review any herbal supplements or vitamins you may take as well.
Look closely at recent changes since symptoms developed. Frequent treatments to the home or your skin, changed medications, new laundry detergents, buying new linens (different fabric type), frequent laundering linens, etc. have all been the root cause of delusory parasitosis cases in the past. Once this was identified and corrected, the symptoms went away permanently.

Pest Control Response to Delusionary Parasitosis

There are many physical and medical reasons that a person may get the “creepie crawlies” and skin irritations. However, it is often very difficult to ascertain the root of the problem when the sufferer will consider no other possibility than insect activity.

There are certainly times when unusual pest infestations are located, treated, and the skin irritation resolved. However, to apply a pest control treatment with no proof of insect infestation only serves to further the delusion and delay a resolution of the true problem. As a Pest Management Professional, our code of ethics requires a confirmation of insect activity before applying pesticides to your home or business. This confirmation may come from a thorough inspection of your home by a professional or samples captured on sticky insect glue boards, tape, or other means of collections. Responsible pest control companies have policies against applying pesticides without having identified a target pest. There are no invisible bugs. Even the smallest insects and biting mites are visible and can be found using sticky-board monitors and other insect trapping techniques.

Delusionary parasitosis is a life-altering disorder which severely affects the quality of life for those who suffer. If you have had your home inspected by multiple pest control companies, and no insect activity has been located, it is probably time to consider alternate reasons for your discomfort. If you or a loved one suffers from symptoms described above, we encourage you to speak with a medical practitioner for the best course of treatment.

For more information and excellent citations regarding delusionary parasitosis, please see the article published by the journal American Entomologist and written by Dr. Nancy Hinkle of the University of Georgia, Department of Entomology. https://academic.oup.com/ae/article/46/1/17/2389588?login=false