Delusional Parasitosis (Ekbom Syndrome)

Delusional parasitosis, also known as Ekbom syndrome, is an uncommon mental health condition in which you believe you’re infested with a living organism even though medical test results show you’re not.

For example, you might be convinced that you’re infested with parasites, fleas, worms, mites, bacteria or fungi.

Other names for it include delusional infestation and psychogenic parasitosis. It’s a specific form of delusional disorder.

In most cases, delusional parasitosis (DP) develops from an existing condition or as a side effect of a medication. This is called secondary DP. When it happens alone, it’s known as primary DP.

It may feel as if something is crawling on or underneath your skin. The sensations you feel are real. But the cause comes from your brain, not your skin. This may be confusing and hard to accept. Your feelings are valid. But try to stay open to other possible causes of your symptoms so you can get the relief you need.

The good news is that medications that balance brain chemical activity work well to treat symptoms.

Symptoms of delusional parasitosis

The main symptom of delusional infestation is that you believe you have a parasitic infection even though there’s medical proof that you don’t. This belief lasts for at least six months.

You may feel like bugs are crawling in or on your skin, a symptom called formication. The sensation is real, but it’s not coming from actual parasites.

When you have DP, you may:

• Pick at your skin, which may cause scratches, ulcers and scars
• See many healthcare providers, including dermatologists
• Fumigate your living space
• Take your pet(s) to the vet for inspection and treatment
• Try DIY methods to try to get rid of parasites, like antiseptics, disinfectants and insecticides
• Convince loved ones that you have a parasitic infection (and/or that they have one)

You may also feel frustrated or helpless that healthcare providers don’t believe you. These feelings are understandable. But it’s important to know that your provider does want to help. They’ll focus on your symptoms and getting you better.

Delusional parasitosis causes

Researchers don’t know the exact cause of this condition. They think it may be due to overactive dopamine signaling in your brain.

Most often, delusional infestation develops from another condition. Psychiatric disorders that can lead to it include:

• Schizophrenia
• Obsessive-compulsive disorder
• Illness anxiety disorder

Other causes of the symptoms may include:

• Substance use, including stimulant use (like methamphetamine and cocaine) or alcohol withdrawal
• Medical conditions, like an overactive thyroid, a vitamin B12 deficiency and liver disease
• Neurologic conditions, like dementia, stroke, multiple sclerosis and meningitis
• Non-parasitic infections, like HIV, tuberculosis and syphilis
• Side effects of medications, like certain antiseizure medications, stimulants, antibiotics, steroids and antifungals

Complications

Without treatment, complications of delusional parasitosis may include:

• Scarring from frequent skin picking
• Rashes (contact dermatitis) from experimental treatments
• Intense distress, which may affect your daily life and relationships

How doctors diagnose delusional parasitosis

First, a healthcare provider will check for parasitic infections. They’ll:

• Ask about recent travel, household pets and exposure to loved ones with similar symptoms
• Do a physical exam, closely looking at the affected areas of your body
• Do a skin biopsy
• Order lab tests

If the results show that you don’t have a parasitic infection, the next step is to find out if there’s an underlying cause of your symptoms. Your provider may recommend other blood and pee tests to check for conditions like vitamin deficiencies and thyroid issues.

In some cases, there isn’t an underlying cause of delusional parasitosis.

How is it treated?

Antipsychotics are the go-to treatment for delusional parasitosis. These medications help eliminate the crawling sensations that you feel. Your healthcare provider may prescribe one of the following medications:

• Risperidone
• Olanzapine
• Aripiprazole
• Paliperidone
• Quetiapine
• Pimozide

You’ll start on the lowest possible dose to try to prevent medication side effects. It may take up to six weeks to notice the full effect of this treatment.

What can I expect if I have delusional parasitosis?

In most cases, antipsychotics work well to treat delusional parasitosis symptoms. After some time, your healthcare provider may taper you off the medication. If symptoms come back, starting the medication again usually works.

These medications can have disruptive side effects, like:

• Muscle stiffness and abnormal movements
• Weight gain
• Increased risk of Type 2 diabetes
• Fatigue or sedation

You’ll need to see your provider regularly to make sure the medication is helpful. Let them know if you develop any side effects.