Chapter 66 Psychocutaneous diseases
1. How do the fields of psychiatry and dermatology overlap?
Many studies confirm that a high percentage of dermatology patients have coexistent psychiatric morbidity. Our understanding of this phenomenon remains limited. We do know that the skin and nervous system have the same embryologic origin, and that tactile stimulation is critical for full neuropsychological development, but many questions remain.
3. How often do patients with dermatologic disorders have associated psychologic morbidity?
This figure is difficult to assess; however, some studies have reported that more than 40% of all dermatologic patients have associated psychologic morbidity. Although many skin conditions are trivial, they are usually visible to the patient and often to the public. Healthy-appearing skin is a reflection of health and well-being, and abnormalities can seriously affect the patient’s happiness.
Gupta MA: Psychosomatic dermatology: is it relevant? Arch Dermatol 126:90–93, 1990.
4. What is the differential diagnosis of patients who complain that they are infested with parasites?
6. What is “delusions of parasitosis”?
These patients falsely believe that their skin is infested with parasites. They often describe insects mating, laying eggs, and crawling around in their skin. They do not admit to actually seeing the insects themselves, as they are not hallucinating. On presentation, patients may bring in specimens containing hair, lint, and even living organisms for examination (Fig. 66-1). They develop elaborate purification rituals and are often well known to pest control organizations. It is not uncommon for the delusion to be shared by other family members. This is called folie à deux.
Figure 66-1. Scale, scabs, and hair brought in by a patient with delusions of parasitosis who insists that these are parasites.
Edlich RF, Cross CL, Wack CA, Long WB 3rd: Delusions of parasitosis, Ann J Emerg Med 27:997–999, 2009.
8. How do you treat this problem?
Delusions, like hallucinations, are psychotic symptoms that are theorized to result from increased levels of dopamine in parts of the brain. Patients with delusions of parasitosis have been shown to respond to neuroleptics; in particular, the dopamine antagonist pimozide (Orap) is, historically, the commonly used treatment. However, more recent anecdotal success has been reported with other agents having fewer side effects, including risperidone, olanzapine, and escitalopram. Although, large, well-controlled, randomized trials comparing the efficacy of these drugs are lacking, these drugs are now probably the drugs of choice.
9. What are the major side effects of pimozide?
• Extrapyramidal symptoms: Dystonia (muscle spasm), akathisia (motor restlessness), Parkinsonian-like syndrome (characterized by a pill-rolling tremor, rigidity, stiffened gait, and flattened facial expression)
12. What is dysmorphophobia?
In syndromes of dysmorphophobia, patients hold delusional beliefs about the structure or function of their skin. Symptoms range from complaints of excessive facial redness, scarring, or large pores, to olfactory delusions in which patients feel they are passing excessively smelly flatus or emitting body odor that drives people away. Diagnosis and treatment are similar to those for delusions of parasitosis. Prognosis is poor, especially in women with facial symptoms, who tend to be severely depressed and even suicidal. Patients with olfactory delusions can be driven to homicide.
13. Name the three major categories of self-inflicted skin lesions. What differentiates them?
• Obsessive-compulsive disorders: Patients acknowledge being driven to self-inflict skin lesions through conscious repetitive action.
14. What are the clinical manifestations of dermatitis artefacta?
The self-inflicted lesions vary widely in morphology and distribution. Depending on the method used, it is possible to see blisters from suction cups, burns from caustic chemicals or cigarettes, edema and ulcerations from the use of elastic bands, or deep scars from the use of glass or knives. Lesions are often bizarre and irregularly rectilinear (Figs. 66-2 and 66-3). They are necessarily within reach. Dermatitis artefacta is more common in women.
15. How should patients with dermatitis artefacta be treated?
In most patients, the creation of the skin lesions satisfies an internal psychological need. In some cases, the disease is transient and triggered by a recent event or stress; however, in many cases, the disease is chronic or recurrent, and it is best evaluated by a qualified psychiatrist or psychologist with expertise in this area. In patients who refuse psychiatric referral, some success has been reported with atypical antipsychotic agents and selective serotonin reuptake inhibitors at higher doses.
16. What is the Gardner-Diamond syndrome?
Also known as autoerythrocyte sensitization syndrome or psychogenic purpura, this disorder is characterized by the sudden unexplained appearance of purpura in young and middle-aged women. Skin lesions are associated with times of stress and are often preceded by burning pain. Permanent damage is rare. The exact etiology of the purpura remains controversial. Patients usually deny a history of trauma. Some individuals have been reported to have a positive skin test to their own red blood cell membranes, but laboratory evaluation is usually otherwise unremarkable. Interestingly, similar lesions have been produced by suggestion under hypnosis. Most authors believe that the disorder represents a factitious dermatitis.
17. How do Munchausen syndrome and Munchausen syndrome by proxy differ?
Munchausen syndrome is a chronic factitious disorder in which patients totally fabricate their symptoms, self-inflict lesions, or exaggerate or exacerbate a preexisting physical condition. The motive for the behavior remains unclear. Unfortunately, the disorder often leads to multiple hospital admissions and unnecessary procedures, surgery, and laboratory studies. When confronted with evidence that the symptoms are factitious, patients usually deny the allegations and leave against medical advice, only to repeat their actions in another hospital, city, state, or country.
20. How do you differentiate among the different forms of nonscarring alopecia?
In alopecia areata, there usually are circular areas of noninflammatory, nonscarring alopecia with “exclamation point” hairs at the margins, and there may be associated nail pitting. Tinea capitis is characterized by patchy alopecia with varying degrees of erythema and scale that is KOH and/or fungal culture positive. In patient with traction alopecia, a distinct pattern that corresponds to a hair style is present (e.g., corn rows).
In trichotillomania, irregular patches of nonscarring, noninflammatory alopecia are covered with broken-off hairs of variable lengths that are scattered randomly between empty hair follicles (Fig. 66-4). Patients with trichotillomania often pull out their upper lid eyelashes but leave the lower lid eyelashes, as these are more difficult to grasp. Patients with alopecia areata may have eyelash loss on both the upper and lower lids.
22. What is trichotemnomania?
23. What are neurotic excoriations?
In this disorder, patients compulsively pick at their skin. Lesions may be preceded by focal pruritus or insect bites, or they may be generated de novo by rubbing. Once initiated, ritualized picking of all lesions occurs when they catch the patient’s attention, or at a particular hour or location. On exam, lesions are found in all stages of development, ranging from ulcerations with hyperpigmented or hypopigmented margins to hypertrophic nodules and atrophic scars. They are usually found within easy reach of the dominant hand (Fig. 66-5).
24. How do you treat this disorder?
Obsessive-compulsive disorders have been theorized to be associated with a deficiency of the neurotransmitter serotonin in the brain. Not surprisingly, patients with neurotic excoriations and trichotillomania who have an underlying obsessive-compulsive disorder have been shown to respond to serotonin reuptake inhibitors such as fluoxetine (Prozac). Isolated case reports have also reported success with various other medications including doxepin, pimozide, and olanzapine. Hypnosis and behavioral modification treatment has also been used with anecdotal success.
Key Points: Psychocutaneous Diseases
2. Patients with delusions of parasitosis have monosymptomatic hypochondriacal psychosis; the remainder of their mental functions are typically normal.
25. What are the side effects of fluoxetine?
The major side effects include anxiety, insomnia, headache, tremor, dizziness, sweating, and gastrointestinal complaints, such as nausea and diarrhea. Although a relatively safe medication, this drug should not be administered to patients on monoamine oxidase inhibitors or to those individuals with a bipolar disorder.
26. What is glossodynia?
Glossodynia, or painful tongue, is one of the many atypical pain syndromes encountered in dermatology. Others include burning mouth syndrome (diffuse burning of the oral mucosa), vulvodynia, burning feet syndrome, and atypical facial pain. Patients with these disorders often have underlying depression and often respond to antidepressants, such as amitriptyline or doxepin. Isolated cases have also responded to antipsychotic agents, such as olanzapine or anticonvulsants such as gabapentin.
27. Name some primary dermatologic disorders that might result in secondary psychiatric problems. What sorts of problems might these patients have?
As an organ of self-expression, the skin plays a key role in emotional development and often defines interaction with others. Major disfiguring conditions, such as cystic acne, can result in a poor self-image and feelings of isolation and anger. Studies reveal that these individuals also suffer from higher rates of substance abuse, unemployment, and mental illness than the general population.
