Formication is a symptom where you hallucinate the feeling of insects crawling in, on or underneath your skin. This symptom has many possible causes, including mental health disorders, medical conditions and more. This symptom is often treatable, with available treatments depending on the cause and other factors.


What is formication (tactile hallucination)?

Formication is a specific type of hallucination that feels like insects crawling in, on or underneath your skin. The name “formication” comes from the word “formica,” which is the Latin word for “ant.”

Certain areas in your brain work cooperatively to process signals from your tactile sense (informally known as your sense of touch). Tactile hallucinations are when those brain areas act like they’re processing signals from your body even though there aren’t any such signals.

Because your brain is acting like its receiving signals, these hallucinations feel completely real. A person having them may struggle to tell the difference between what’s real and what’s not. People who experience this hallucination often feel an immediate — and even uncontrollable — urge to scratch or pick at the area of skin affected. This often leads to skin-picking or causing injuries to the skin and tissues underneath.


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Possible Causes

What are the most common causes of formication?

There are a few main ways that formication happens:

  • Substance use or withdrawal from substances.
  • Mental health conditions that involve psychosis and hallucinations.
  • Brain-specific conditions.
  • Medical conditions that can affect your brain or other body systems.
  • Too little of either vitamin B9 (folate) or vitamin B12.

Drug use and withdrawal

Prescription and recreational drugs are among the most common causes of formication. Withdrawal from drug misuse or alcohol use can also cause formication. The most common drugs that can cause this include:

  • Stimulants: Cocaine, methylphenidate and amphetamines, as well as other stimulant drugs, can cause formication. This is more likely to happen with misuse of these drugs, especially recreational use of drugs like cocaine, methamphetamine and phencyclidine (PCP).
  • Antidepressants: Medications like phenelzine or bupropion are possible causes of this symptom.
  • Anti-seizure and anti-tremor medications: Levetiracetam and topiramate, which treat seizures, are possible causes of formication. Other anti-Parkinson’s disease drugs that can cause it include amantadine, piribedil, pramipexole, ropinirole and thihexylphenidyl.
  • Sedative/hypnotic medications: These are medications that help make you drowsy or relaxed. A medication in this class that can cause formication is eszopiclone (better known under the brand name Lunesta®).
  • Medications that affect hormone levels: Cabergoline, a medication that lowers levels of the hormone prolactin, can cause formication.
  • Antifungal and antibiotic medications: Researchers have found that some antibiotic and antifungal medications, such as ciprofloxacin and ketoconazole, can cause formication.

Formication can happen with any of the above drugs. It can also happen if a person develops a dependence on a drug and then stops taking it, causing withdrawal.

Mental health conditions

Most mental health disorders where formication is possible involve a condition called psychosis. This means a person “disconnects” from reality. This disconnection happens in two ways:

  • Hallucinations: Formication is a tactile hallucination, meaning it affects your sense of touch. However, formication can also drive delusions.
  • Delusions: These are false beliefs that someone holds onto very strongly, even when others don't believe them or there's plenty of evidence the belief isn’t true. Many people who have formication believe they’re infested with parasites or insects because of the hallucination.

Mental health conditions that can involve formication include:

Neurologic conditions

Neurologic conditions (which specifically affect your brain or nervous system) can cause formication. Examples include:

Medical conditions

Many conditions that affect your systems in your body and brain can cause formication. Some examples include:

Care and Treatment

How is formication treated?

Treating formication can take many forms, depending on why it happened.

  • When a drug causes it: If it happens because of a drug (either prescription or recreational), formication usually stops once the drug wears off. With prescription drugs, it may take adjustment of the dose to either stop formication or gradually lower the dose to stop that drug and try another.
  • When a medical condition causes it: With medical conditions, treating the underlying conditions may be all it takes to stop formication. However, this isn’t always the case, especially when the conditions are incurable.
  • When a mental health condition causes it: Treating the underlying mental health condition that causes formication may stop this symptom or reduce how severe it is or how often it happens.

Because there are so many potential ways to treat formication, your healthcare provider is the best person to tell you the possible treatment options. They can offer you options based on your condition(s), health history and other factors.


What can I do at home to treat formication?

Formication isn’t a symptom you should try to treat at home, as it takes a trained healthcare provider to determine what’s causing it. You should also seek medical attention if you have this symptom unexpectedly, as this symptom can happen with certain dangerous conditions like stroke or drug overdoses. You should also contact a healthcare provider if this symptom could have a connection with a prescribed medication you take.

How can formication be prevented?

Because it happens unpredictably and with so many possible conditions, there’s no way to prevent formication entirely. The only ways you can reduce your risk of developing it are:

  • Avoiding recreational drug use.
  • Avoiding heavy and regular alcohol consumption so you don’t develop dependence or withdrawal.
  • Using safety equipment and gear to avoid head injuries.


When To Call the Doctor

When should formication be treated by a doctor or healthcare provider?

You should call a healthcare provider if you develop formication after starting a new medication or if you develop it after diagnosis with one of the conditions listed above. You should seek emergency medical care if you develop formication in connection with symptoms of a stroke or any kind of drug overdose.

Stimulant overdose symptoms

The most common symptoms of a stimulant drug overdose are:

  • Anxiety, agitation, paranoia or restlessness.
  • Chest pain or pressure.
  • Fast breathing.
  • False or irregular heartbeat/pulse.
  • Hallucinations (especially skin-oriented ones).

Stroke symptoms

To spot the symptoms of a stroke, remember to think FAST.

  • F is for face. Ask the person to smile. Look for a droop on one or both sides of their face, which is a sign of muscle weakness or paralysis.
  • A is for arm. A person having a stroke often has muscle weakness on one side. Ask them to raise their arms. If they have one-sided weakness (and didn’t have it before), one arm will stay higher while the other will sag and drop downward.
  • S is for speech. Strokes often cause a person to lose their ability to speak. They might slur their speech or have trouble choosing the right words.
  • T is for time. Time is critical, so don’t wait to get help! If possible, look at your watch or a clock and remember when symptoms start. Telling a healthcare provider when symptoms started can help the provider know what treatment options are best for you.

Additional Common Questions

How can I help a loved one who seems to have formication among other symptoms of psychosis?

Because people with psychosis have trouble telling the difference between what’s real and what isn’t, they often can’t recognize or understand that they have these symptoms or a mental health condition. Commonly, they’ll dismiss or resist suggestions that they get care because they don’t believe anything is wrong with them. That’s why psychosis can be a source of frustration or fear for someone with these symptoms or their loved ones.

If you notice a loved one showing signs of a psychotic condition, you can try to help them by doing the following:

  • Ask how you can help. People with psychosis or conditions that involve it may talk about their symptoms without realizing these are symptoms of a mental health issue. Listening and communicating may help your loved one see that others care for them and want to help.
  • Encourage them to see someone who can help. Treatment for psychosis, especially medications, can make a big difference in a person’s ability to tell what’s real and what’s not. Once medications take effect, they may start to understand that they have a condition that needs care.
  • Don’t judge or argue. People with psychosis have trouble telling what’s real and what isn’t. To compensate for this disconnection from reality, their brain may generate things that only they can see or hear. These things will feel real, so arguing or showing them evidence isn’t helpful. It’s also important not to judge someone who shows these symptoms. That can make them feel even more isolated, and it may push them away from seeking help.
  • Stay calm. People with psychotic symptoms can feel afraid or frustrated when others don’t seem to understand or believe them. That can make them pull away from others, making them feel even more alone. Try to remain calm, reassure your loved one and help them feel as safe as possible (don’t make them feel trapped or threatened). If there’s a lot of noise nearby, try to make the environment quieter or ask if you can go somewhere more peaceful.
  • Get help in emergencies. People with psychosis and related conditions have a much higher risk of dying by suicide. If someone with psychotic symptoms says they’re thinking about harming themselves or others, or if they show severe paranoia, agitation or act abusively or violently, then you should immediately call your local emergency services.

How to respond to dangerous behavior

People with formication with schizophrenia or other psychotic disorders may have an increased risk of self-harm and suicide. You should go to the ER or call 988 or 911 (or your local emergency services number) if you have thoughts about harming yourself, including thoughts of suicide or about harming others. You should also seek immediate help if you suspect someone you know is in imminent danger of harming themselves.

To get help in these situations, you can call any of the following:

  • National Suicide Prevention Lifeline (United States). This line can help people who are struggling with suicidal thoughts or impulses. To call this line, dial 988.
  • Local crisis lines. Mental health organizations and centers in your area may offer resources and help through crisis lines if you’re struggling with thoughts of suicide, self-harm or harming others.
  • 911 (or your local emergency services number). You should call 911 (or the local emergency services number) if you feel like you’re (or someone you know is) in immediate danger of self-harm or suicide. Operators and dispatchers for 911 lines can often help people in immediate danger because of a severe mental crisis and send first responders to assist.

A note from Cleveland Clinic

Formication is a symptom where you hallucinate the feeling of insects crawling in, on or under your skin. This symptom can be very upsetting or disturbing, leading to other issues like self-injury from scratching or trying to get the insects out from under or inside of your skin. This symptom can happen for many reasons, many of which are treatable.

Because this symptom can happen with dangerous or life-threatening conditions, it’s a good idea to talk to a healthcare provider or get medical attention as soon as possible. When this symptom happens with certain mental health conditions, don’t try to convince a person that what they feel isn’t real. Instead, offer them help in figuring out what’s causing this symptom. That can lead them to medical professionals who can diagnose and treat formication effectively, putting an end to this symptom.

Medically Reviewed

Last reviewed on 08/09/2022.

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