Бред паразитозов: причины, диагностика и лечение

Medical condition

People with delusional parasitosis believe that "parasites, worms, mites, bacteria, fungus" or some other living organism has infected them, and reasoning or logic will not dissuade them from this belief.

The cause of delusional parasitosis is unknown. It may be related to excess dopamine in the brain's striatum, resulting from diminished dopamine transporter (DAT) function, which regulates dopamine reuptake in the brain. Examination to rule out other causes is key to diagnosis. Pruritus and other skin conditions are most commonly caused by mites, but may also be caused by "grocer's itch" from agricultural products, pet induced dermatitis, caterpillar/moth dermatitis, or exposure to fiberglass. Several drugs, legal or illegal, such as amphetamines, dopamine agonists, opioids, and cocaine may also cause the skin sensations reported. Diseases that must be ruled out in differential diagnosis include hypothyroidism, and kidney or liver disease.

As of 2019, there have not been any studies that compare available treatments to placebo. The only treatment that provides a cure, and the most effective treatment, is low doses of antipsychotic medication. Cognitive behavioral therapy (CBT) can also be useful. Risperidone is the treatment of choice. Reassuring the individual with DP that there is no evidence of infestation is usually ineffective, as the patient may reject that.

The average duration of the condition is about three years. Since the early 2000s, a strong internet presence has led to increasing self diagnosis of Morgellons. The eponymous Ekbom's disease was changed to "delusions of parasitosis" in 1946 in the English literature, when researchers J Wilson and H Miller described a series of cases, and to "delusional infestation" in 2009. The most common name since 2015 has been "delusional parasitosis".

Mary Leitao, the founder of the Morgellons Research Foundation, coined the name Morgellons in 2002, reviving it from a letter written by a physician in the mid 1600s. Leitao and others involved in her foundation (who self identified as having Morgellons) successfully lobbied members of the U. S. Congress and the U. S. Centers for Disease Control and Prevention (CDC) to investigate the condition in 2006. The CDC published the results of its multi year study in January 2012. The study found no underlying infectious condition and few disease organisms were present in people with Morgellons; the fibers found were likely cotton, and the condition was "similar to more commonly recognized conditions such as delusional infestation". An active online community has supported the notion that Morgellons is an infectious disease, and propose an association with Lyme disease. Publications "largely from a single group of investigators" describe findings of spirochetes, keratin and collagen in skin samples of a small number of individuals; these findings are contradicted by the much larger studies conducted by the CDC. after publishing a 1951 account of what she called a mite infestation. Her detailed description of her own experience with mites was later shown to be incorrect, Matan Shelomi says the paper has done "permanent and lasting damage" to people with delusional parasitosis, "who widely circulate and cite articles such as Traver's and other pseudoscientific or false reports" via the internet, making treatment and cure more difficult.