Indirect Effects – “Mystery Bites” Announcements Speaking Today: Shea Gatewood Speaking Next Thursday: Angela Jones Next Quiz??

Quiz Review 1. –a. American Dog Tick –b. Male –c. Rickettsia, overwinters in the ticks 2: C, B, D 3: D 4: C 5: B 6: E 7: Allergies

Curve

Psychological Effects “Illusional” Parasitosis = “Invisible Itches” –Incorrectly ascribing a real medical response to an arthropod cause Entomophobia/Arachnophobia –Persistent irrational fear of insects/arachnids Delusional Parasitosis –Unshakable false belief that live arthropods are on/in the skin.

“Invisible Itches” Actual irritation whose source cannot be identified by the patient –Arthropod sources Allergen sources such as dust mites Biting arthropods (bed bugs, fleas, mites, etc.). Generally delayed reaction. –Non-Arthropod Sources – Environmental Physical –Temperature/humidity changes –Fibers (paper, fabric) – NOT Morgellon’s Syndrome –Electrical (esp. static). Chemical –Household products (esp. fabric detergents & related) –Solvents or other volatiles

Entomophobia/Arachnophobia Subgroup of zoophobias 3 Characteristics –Perisistent irrational fear of insects. –Significant distress in patient who is also aware that the fear is unreasonable. –Not due to other mental/physical disorder (e.g. obsessive/compulsive order, schizophrenia, etc.). Phobic object may be insects in general, a single group of insects, or infestation by real/imagined insects.

Delusional Parasitosis (DP) Patient experiences state of being infested, not the fear as in phobias. Described by Ekbom (1938) who also described Restless Leg Syndrome. Both carry his name. Experience can involve all senses Categorized as a “Non-Bizarre Delusional Disorder” in diagnostic manuals. Two kinds –Primary – DP is the entity itself –Secondary – DP is a symptom of a superior psychiatric condition Functional – Clinical depression association Organic – Chemically-related

Delusional Parasitosis Presentation Elaborate description of parasites Ritualistic purifications Obsessive self mutilation Excessive application of insecticides/creams to skin “Matchbox sign” Delusional infestation may be shared (or believed to be shared) by other family members

Primary Delusional Parasitosis No other symptom or deterioration in mental/psychiatric state. AKA “monosymptomatic hypochondriacal psychosis” or “true DP” Most common in Caucasian women, >90% of these are > 40 years old. Prevalence greater among less educated, lower income population. Long-term treatment with psychotropics generally indicated.

Secondary DP Much more common than Primary DP Epidemiologically increases during time of social stress. A reaction to a primary problem (e.g. drug abuse) –Treatment generally targets the primary problem. Patient is generally aware that the sensation is delusional (unlike primary). –Generally more easily convinced to see a mental health professional

Secondary DP Examples Formication and visual hallucinations secondary to methamphetamine abuse resulted in the self-infliction of these papular and scabbed lesions. The patient believed that “bugs” were in her skin. In addition to her face, she had lesions on her arms, shoulders, and neck. She had a history of methamphetamine use, which was concurrent with her alleged infestation. “coke bugs,” “meth mites,” and “amphetamites”

Secondary DP Examples The patient complained of a worm infestation in his neck. He used a pair of scissors to excise the imagined worms. The toxicology screening of this patient was positive for cocaine, opiates, and benzodiazepines.

Secondary DP Examples Middle-aged woman presenting with excoriated papules and scarring on the arms and back (not shown). Believed that she was infested with “skin mites.” Scarring is a telltale sign of chronicity. Neurotic excoriations generally are caused by the patient’s fingernails; they have a uniform disciform size and shape & are located in accessible parts of the body.

Dermatologic Insect bite reaction or infestation Chronic folliculitis Dermatitis herpetiformis Psychiatric Schizophrenia spectrum disorders Affective disorders with psychotic features Anxiety disorders, particularly obsessive– compulsive disorder Hematologic/Oncologic Severe anemia Lymphoproliferative disorders, lymphoma Myeloproliferative disorders, multiple myeloma Breast cancer Metabolic Uremia Cholestasis Carcinoid syndrome Endocrine Diabetes mellitus Hyper- or hypothyroidism Hyper- or hypoparathyroidism Substance abuse Cocaine Amphetamines Alcohol withdrawal (DTs) Infectious AIDS Hepatitis Syphilis Tuberculosis Meningitis/Encephalitis Neurologic Neuropathies Parkinson's disease Huntington's disease Multiple sclerosis Cerebrovascular accident Traumatic brain injury Dementia Some Reported Causes of Secondary DP. Source: Bury & Bostwick (in press)Bury & Bostwick (in press)

Related Conditions Delusory cleptoparasitosis -- sufferer believes the infestation is in their dwelling, rather than on/in their body. Formication – Sensation of stinging, crawling, biting on skin but patient knows that it is not caused by arthropods. Morgellon’s Syndrome –Sensation of crawling/biting believed (by patient) to be caused by fibers. –New description (2004), not universally accepted. –Morgellon Research Foundation has a case definition.case definition.

How to Handle “Mystery” Bites: First, look. Treat all bite complaints as legitimate. Biting pests are never invisible to you There are no “paper mites”, “cable mites” Inspect “bite” area, collect any specimen. Dab area with damp cotton, deposit in alcohol. Dab area with tape, place on paper. Send in for analysis. Pest control provider can install traps or other monitoring devices

How to Handle “Mystery” Bites: If Nothing is Found 1.Person may be being bit in some other location. 2.Suspect skin condition (many look & feel like bites), refer to dermatologist 3.Suspect environmental condition (static, chemicals, etc.). Refer to industrial hygenist 4.May be delusory parasitosis. Recruit assistance. Proceed in the following order