Mystery Bites
Is it a bug bite or something else?
Often a dermatologist or other medical providers are needed to resolve the issue with mystery bites.
Among the millions of insects, spiders, mites and related creatures in the world, only a few species affect us directly with their allergens, stings, bites and blood-sucking tendencies. The itchy bite of a mosquito or the painful sting of a yellowjacket are both familiar and easy to identify. Harder to see are scabies mites and even head lice, but these conditions are well-known and treated with medications.
Sometimes it’s not a bite
Occasionally a person will feel itching or pin prick sensations and become overly worried that some invisible insect or mite is biting them, when none can be found. This could be the condition known as Ekbom syndrome, delusory parasitosis, or DP for short. People who have DP have an unshakable, yet false, belief that they are infested with insects, mites, worms or some other parasitic organism, when none can be found.
It is important for scientists and the public to be aware of the signs of Ekbom Syndrome and understand how to respond.
Causes of itches, biting and stinging sensations
There are many causes of itches and biting/stinging sensations, so it is best to keep an open mind about the cause. The following is a partial list of common sources of irritation. If arthropods cannot be found, the cause is likely to be in one of the other groups.
Small arthropods
- Bed bugs
- Fleas
- Mosquitoes
- Biting midges (no-see-ums)
- Ticks
- Head lice (rarely body and public lice)
- Various mites – Scabies, straw itch, bird or rodent mites
- *Chiggers are not found in NY, but tick larvae can be mistaken for chiggers
Environmental Irritants
- Low humidity, leading to dry skin
- Fiberglass insulation
- Paper or fabric fibers
- Animal hairs
- Poisonous weeds (poison ivy, giant hogweed and many others)
- Chemical pollutants – solvents, ammonia, tobacco smoke, etc.
Household Products
- Detergents, soaps
- Cosmetics and hair products
- Cleansers with ammonia or bleach
- Flea and tick control products in clothing or on pets
- Clothing with fire retardant or formaldehyde
Health Conditions
- Pregnancy or menopause
- Diabetes and other endocrine disorders
- Food allergies
- Reaction to medication
- Drug use or withdrawal symptoms
- Skin conditions (eczema, psoriasis, etc)
- Liver or kidney disease
- Stress, anxiety, depression
- Illness anxiety disorder
- Ekbom Syndrome
Typical Sample Provided by an Ekbom Syndrome Sufferer
Often, samples like these contain no identifiable arthropods, yet the submitter insists that their experience is real.
Ekbom Syndrome
(also called delusory parasitosis)
Because Ekbom Syndrome is a health condition, cooperative extension agents (and anyone who is not a medical practitioner) should not attempt to diagnose this condition in others. In fact, entomologists and cooperative extension agents can only determine if an arthropod is identifiable in a sample. Other medical, environmental and household product-related health issues must be determined by other means. However, it is important for scientists and the public to be aware of the signs of Ekbom Syndrome and understand how to respond.
Common Behaviors of Ekbom Syndrome
Picking at Skin
Common behaviors attributed to Ekbom Syndrome include subjects scratching the skin raw, picking at scabs, and collecting household dirt, debris, scabs and hair for identification. Long ago, this became known as “matchbox syndrome” as subjects would sometimes collect evidence into matchboxes for examination. Often, samples like these contain no identifiable arthropods, yet the submitter insists that their experience is real.
Belief that Insects or Mites are Burrowing into the Skin
Common beliefs are that insects or mites are burrowing into the skin, reproducing inside the person’s body or orifices, flying around, or surviving pesticide treatments. It is also common for individuals to believe that the bugs can disappear and reappear or change color.
Excessive Laundering
Subjects might also wash bed linens and clothing repeatedly, compulsively clean or even use dangerous chemicals on their skin or in their home in an attempt to treat what they believe is biting them. Repeated exposure to cleaning chemicals, rubbing alcohol and pesticides can worsen itching sensations and create a dangerous cycle.
Bird Mites
A specific fear among Ekbom Syndrome subjects is that bird mites are to blame for their condition. Bird mites, visible to the naked eye, parasitize birds and live in the nest materials when they are not within the feathers of a host. Birds nesting on buildings can bring mites into contact with humans, but bird mites cannot live without their avian hosts. They do not infest homes or the human body and will die off in a matter of days once the birds leave the nest.
An Entomologists Role
It can be very difficult for a person with mystery bites to accept that their condition does not involve insects or mites. An entomologist’s role in such cases is to faithfully examine samples for signs of arthropods and report those results. If nothing is found, more samples can be examined but no pest control action should be recommended. It can be helpful to remind the individual that NOT having bed bugs, fleas or bird mites is a good outcome of your examination. Bed bugs can be persistent and costly to eliminate and fleas transmit diseases. Often a dermatologist or other medical providers are needed to resolve the issue with mystery bites.
- “Invisible Itches: Insect and Non-Insect Causes,” University of Florida Extension
- “Delusory Parasitosis” by Nancy Hinkle, American Entomologist Volume 46, No 1. (pdf)