The Full Wiki

Trypanophobia: Wikis


Note: Many of our articles have direct quotes from sources you can cite, within the Wikipedia article! This article doesn't yet, but we're working on it! See more info or our list of citable articles.


From Wikipedia, the free encyclopedia

Trypanophobia is the extreme and irrational fear of medical procedures involving injections or hypodermic needles. It is occasionally referred to as aichmophobia, belonephobia, or enetophobia, names that are technically incorrect because they simply denote a “fear of pins/needles” and do not refer to the medical aspect of trypanophobia. Trypanophobia is a term that is rarely used among medical professionals. In the United States National Library of Medicine database of medical journal articles, the term "trypanophobia" cannot be found, although the database contains several journal articles referencing needle phobia.[1]  The name that is in common usage is simply needle phobia.


Overview and incidence

The condition was officially recognized in 1994 in the DSM-IV (Diagnostic and Statistical Manual, 4th edition) as a specific phobia of blood/injection/injury type. Phobic level responses to injections cause sufferers to avoid inoculations, blood tests, and in the more severe cases, all medical care.

It is estimated that at least 10% of American adults are trypanophobic, and it is likely that the actual number is larger, as the most severe cases are never documented due to the tendency of the sufferer to simply avoid all medical treatment.[2]

Evolutionary basis

According to Dr. James G. Hamilton, author of the pioneering paper on needle phobia, it is likely that the form of needle phobia that is genetic has some basis in evolution, given that thousands of years ago humans who meticulously avoided stab wounds and other incidences of pierced flesh would have a greater chance of survival.[2]


Although trypanophobia is defined simply as an extreme fear of medically related shots/injections, it appears in several varieties.



Although most specific phobias stem from the individuals themselves, the most common type of trypanophobia, affecting 50% of trypanophobes, is an inherited vasovagal reflex reaction. Approximately 80% of trypanophobes report that a relative within the first degree exhibits the same disorder.

People who suffer from vasovagal trypanophobia fear the sight, thought, or feeling of needles or needle-like objects. The primary symptom of vasovagal trypanophobia is vasovagal syncope, or fainting due to a decrease of blood pressure.

Many people who suffer from fainting during needle procedures report no conscious fear of the needle procedure itself, but a great fear of the vasovagal syncope reaction. A study in the medical journal Circulation concluded that in many patients with this condition (as well as patients with the broader range of blood/injury phobias), an initial episode of vasovagal syncope during a needle procedure may be the primary cause of needle phobia rather than any basic fear of needles.[3] These findings reverse the more commonly-held beliefs about the cause and effect pattern of needle phobics with vasovagal syncope.

The physiological changes associated with this type of trypanophobia also include feeling faint, sweating, nausea, pallor, tinnitus, panic attacks, and initially high blood pressure and heart rate followed by a plunge in both at the moment of injection.

Although most phobias are dangerous to some degree, trypanophobia is one of the few that actually kills. In cases of severe trypanophobia, the drop in blood pressure caused by the vasovagal shock reflex may cause death. In Dr. Hamilton's 1995 review article on needle phobia, he was able to document 23 deaths as a direct result of vasovagal shock during a needle procedure.[2]

The best treatment strategy for this type of trypanophobia has historically been desensitization or the progressive exposure of the patient to gradually more frightening stimuli, allowing them to become desensitized to the stimulus that triggers the phobic response.  In recent years, a technique known as "applied tension" has become increasingly accepted as an often effective means for maintaining blood pressure to avoid the unpleasant, and sometimes dangerous, aspects of the vasovagal reaction.[4][5][6]


Associative trypanophobia is the second most common type, affecting 30% of needle phobics. This type of trypanophobia is the classic specific phobia in which a traumatic event such as an extremely painful medical procedure or witnessing a family member or friend undergo such, causes the patient to associate all procedures involving needles with the original negative experience.

This form of trypanophobia causes symptoms that are primarily psychological in nature, such as extreme unexplained anxiety, insomnia, preoccupation with the coming procedure and panic attacks.

Treatments that are effective for this form of trypanophobia include cognitive therapy, hypnosis, and/or the administration of anti-anxiety medications.


Resistive trypanophobia occurs when the underlying fear involves not simply needles or injections but also being controlled or restrained. It typically stems from repressive upbringing or poor handling of prior needle procedures i.e with forced physical or emotional restraint.

This form of trypanophobia affects around 20% of needle phobes. Symptoms of this form of trypanophobia include combativeness, high heart rate coupled with extremely high blood pressure, violent resistance, avoidance and flight.

The suggested treatment for this form of trypanophobia is psychotherapy, teaching the patient self-injection techniques or finding a trusted health care provider.


Hyperalgesic trypanophobia is another form that does not have as much to do with fear of the actual needle. Patients with this form of trypanophobia have an inherited hypersensitivity to pain, or hyperalgesia. To them, the pain of an injection is unbearably great and many cannot understand how anyone can tolerate such procedures.

This form of trypanophobia affects around 10% of needle phobes. The symptoms of this form of trypanophobia include extreme explained anxiety, and elevated blood pressure and heart rate at the immediate point of needle penetration or seconds before.

The recommended forms of treatment for this type of trypanophobia include some form of anesthesia, either topical or general.


Whilst witnessing procedures involving needles it is possible for the phobic present to suffer the symptoms of a needle phobic attack without actually being injected. Prompted by the sight of the injection the phobic may exhibit the normal symptoms of vascal vagal syncope and fainting or collapse is common. While the cause of this is not known, it may be due to the phobic imagining the procedure being performed on themselves. Recent neuroscience research shows that feeling a pin prick sensation and watching someone else's hand get pricked by a pin activate the same part of the brain [7]

Comorbidity and triggers

Trypanophobia, especially in its more severe forms, is often comorbid with other phobias and psychological ailments, for example, iatrophobia, or an irrational fear of doctors, is often seen in needle phobic patients.

A needle phobic patient does not need to physically be in a doctor's office to experience panic attacks or anxiety brought on by trypanophobia. There are many triggers in the outside world that can bring on an attack through association. Some of these are blood, injuries, the sight of the needle physically or on a screen, paper pins, examination rooms, hospitals, white lab coats, hospital gowns, doctors, dentists, nurses, the antiseptic smell associated with offices and hospitals, the sight of a person who physically resembles the patient's regular health care provider, or even reading about the fear.


The medical literature suggests a number of treatments that have been proven effective for specific cases of needle phobia, but provides very little guidance to predict which treatment may be effective for any specific case. The following are some of the treatments that have been shown to be effective in some specific cases.

  • Ethyl Chloride Spray (and other freezing agents).  Easily administered, but provides only superficial pain control.
  • Jet Injectors.  Jet Injectors work by introducing substances into the body through a jet of high pressure gas as opposed to by a needle. Though these eliminate the needle, some people report that they cause more pain.[8][9] Also, they are only helpful in a very limited number of situations involving needles i.e insulin and some inoculations.
  • Iontophoresis.  Iontophoresis drives anesthetic through the skin by using an electric current. It provides effective anesthesia, but is generally unavailable to consumers on the commercial market and some regard it as inconvenient to use.
  • EMLA.  EMLA is a topical anesthetic cream that is a eutectic mixture of lidocaine and prilocaine. It is a prescription cream in the United States, and is available without prescription in some other countries. Although not as effective as iontophoresis, since EMLA does not penetrate as deeply as iontophoresis-driven anesthetics, EMLA provides a simpler application than iontophoresis. EMLA penetrates much more deeply than ordinary topical anesthetics, and it works adequately for many individuals.[10]
  • Behavioral therapy.  Effectiveness of this varies greatly depending on the person and the severity of the condition. There is some debate as to the effectiveness of behavioral treatments for specific phobias (like blood, injection, injury type phobias), though some data are available to support the efficacy of approaches like exposure therapy.[11][12] Any therapy that endorses relaxation methods may be contraindicated for the treatment of trypanophobia as this approach encourages a drop in blood pressure that only enhances the vasovagal reflex. In response to this, graded exposure approaches can include a coping component relying on applied tension as a way to prevent complications associated with the vasovagal response to specific blood, injury, injection type stimulus.[4][5]
  • Nitrous Oxide (Laughing Gas).  This will provide sedation and reduce anxiety for the patient, along with some mild analgesic effects.
  • Inhalation General Anesthesia.  This will eliminate all pain and also all memory of any needle procedure. On the other hand, it is often regarded as a very extreme solution. It is not covered by insurance in most cases, and most physicians will not order it. It can be risky and expensive and may require a hospital stay.

See also


  1. ^ United States National Library of Medicine database (Entrez PubMed) [1]
  2. ^ a b c James Hamilton (August 1995). "Needle Phobia - A Neglected Diagnosis". Journal of Family Practice 41 (2): 169-175 REVIEW. PMID 7636457. 
  3. ^ Accurso, V.; et al. (August 2001). "Predisposition to Vasovagal Syncope in Subjects With Blood/Injury Phobia". Circulation 104 (8): 903-907. doi:10.1161/hc3301.094910. PMID 12481980.  [2]
  4. ^ a b Ost, L.G.; et al. (1991). "Applied tension, exposure in vivo, and tension-only in the treatment of blood phobia.". Behaviour Research and Therapy 29 (6): 561-574. doi:10.1016/0005-7967(91)90006-O. PMID 1684704. 
  5. ^ a b Ditto, B.; et al. (2009). "Physiological correlates of applied tension may contribute to reduced fainting during medical procedures". Annals of Behavioral Medicine 37 (3): 306-314. doi:10.1007/s12160-009-9114-7. PMID 19730965. 
  6. ^ Ayala, E.S.; et al. (2009). "Treatments for blood-injury-injection phobia: a critical review of current evidence.". Journal of Psychiatric Research 43 (15): 1235-1242 REVIEW. doi:10.1016/j.jpsychires.2009.04.008. PMID 19464700. 
  7. ^ Morrison, I.; et al. (June 2004). "Vicarious responses to pain in anterior cingulate cortex: is empathy a multisensory issue?". Cognitive Affective and Behavioral Neuroscience 4 (2): 270-278. doi:10.3758/CABN.4.2.270. PMID 15460933.  [3]
  8. ^ Hogan, M.E.; et al. (10 February 2010). "A systematic review of measures for reducing injection pain during adult immunization.". Vaccine 28 (6): 1514-1521. doi:10.1016/j.vaccine.2009.11.065. PMID 20003927. 
  9. ^ Schramm-Baxter, J.R.; Mitragotri, S. (2004). "Investigations of needle-free jet injections.". Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society 5: 3543-3546. PMID 17271055. 
  10. ^ Greenbaum, S.S.; Bernstein, E.F. (September 1994). "Comparison of iontophoresis of lidocaine with a eutectic mixture of lidocaine and prilocaine (EMLA) for topically administered local anesthesia". Journal of Dermaologic Surgery and Oncology 20 (9): 579-583. PMID 8089357. 
  11. ^ Stewart, J.E. (May 1994). "Diagnosis and treatment of phobia". Professional Nurse 9 (8): 549-552. PMID 8008769. 
  12. ^ Shabani, D.B.; Fisher, W.W. (Winter 2006). "Stimulus fading and differential reinforcement for the treatment of needle phobia in a youth with autism". Journal of Applied Behavior Analysis 39 (4): 449-552. doi:10.1901/jaba.2006.30-05. PMID 17236343.  [4]

External Links


Got something to say? Make a comment.
Your name
Your email address