Chapter 104. Psychocutaneous Skin Disease

Scientific advances are shedding new light on the understanding and treatment of long-recognized conditions located at the interface of dermatology and psychiatry. Both arising from ectoderm, the skin and the nervous system are connected by more than just their common origins. The skin is one of the major avenues by which humans perceive the world, and, in turn, are perceived by it. When these perceptions go awry, great distress may result. When the skin is markedly affected by a primary dermatologic condition, psychological sequelae in the form of comorbidity often follow, greatly impacting patient quality of life.

The central nervous system (CNS) can influence the health of other organ systems, including the skin. Psychophysiologic mechanisms for this interaction range from the stress responses mediated by neuroadrenal connections and associated changes in immunologic function, to the systemic and local action of various neuropeptides and neurohormones.1,2

Between 20% and 40% of patients seeking treatment for skin complaints have some type of psychiatric or psychological problem causing or complicating the presenting symptoms.3,4 A large number of these patients lack insight into the possible psychogenic origin of their symptoms and are often reluctant to accept any kind of psychiatric referral. Therefore, in the absence of a psychiatry liaison clinic in the dermatologic setting,4 the dermatologist must be familiar with the most common of these diagnoses, their clinical manifestations (both psychological and dermatologic), and the basic principles of treatment. When approaching these issues, it is important to explore psychiatric, and particularly psychotic, symptoms as well as compliance with medications. Collateral informants such as family members can be quite helpful if the patient grants permission. Lastly, the effects of patient symptoms on familial and social life can be of much assistance in understanding the issues to be addressed.

Following the original description of C. Koblenzer,5 psychocutaneous diseases can be classified on the basis of their primary etiology as:

• Primary psychogenic disorders, which can present with a variety of symptoms and behaviors, usually characterized by self-injury, that can lead to perceived or actual dermatologic conditions, or
• Primary dermatologic disorders that can be either triggered or amplified by contextual causes (e.g., life stresses or interpersonal relationships) that may lead to psychiatric comorbidities such as, anxiety, depression, and distress through their impact on physical appearance and well being. In some instances, the psychiatric comorbidities are not merely the result of the detrimental aspects of skin, but are associated to the pathophysiology of the dermatological disease itself. An example of the latter is the association of psoriasis with depression, in which both conditions share common inflammatory pathways.

The classification can guide in implementing an effective treatment approach including dermatologic, psychiatric, and contextual aspects of the disease aimed to interrupt the circular reinforcement of pathology. In this chapter, we focus on the description of the most frequent primary psychogenic disorders that present to the dermatologist, and require acknowledgement and treatment.

Frequently, these diseases are manifested by self-inflicted dermatosis. The most significant difference between them is the degree of insight or conscious perception of autoinjury. The classification of these disorders as delusional, factitial, somatoform, or compulsive is adapted for the clinical dermatological practice, following the one described in Clinical Management in Psychodermatology6 with the understanding that in many instances, disorders may span through various categories (Box 104-1), and may differ conceptually from the DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, published by the American Psychiatric Association), which is directed towards the psychiatric practitioners7 and clinical studies.

Delusion of Parasitosis

Subjects with delusional disorders present with somatic complaints, no insight into the involved psychological issues, and encapsulated monosymptomatic delusions. Delusions are fixed, false beliefs that are not endorsed by the larger cultural, ethnic, or religious community. Patients’ unshakeable beliefs frequently coexist with a fairly intact character and personality structure. The most frequent form of this condition seen by dermatologists is delusion of parasitosis8 in which patients manifest the belief of being infested with parasites. Because this is frequently the only overt manifestation of the subject's psychosis, these patients most often present to dermatologists and entomologists rather than to psychiatrists. Although we will describe below the more common form of delusions of parasitosis, there are other more rare forms of delusions such as hypochondriacal, where patients believes that they are afflicted by a particular disease (such as AIDS, cancer, etc.), or delusions of body odor. In many instances, patients with body dysmorphic disorder (BDD) may have the unshakeable delusional conviction that they have a severe physical disfigurement.

Epidemiology

This disease predominates in middle aged to elderly females with premorbid social isolation. In approximately 12% of patients, the delusion of infestation is shared or at least endorsed by a family member (folie a deux).9,10

Clinical Findings

Patients with delusional parasitosis frequently present to the clinician in an anxious, ruminative, overwhelmed state, with a history of visits to multiple physicians without satisfaction. In addition to proffering a long and detailed history that includes visual or tactile hallucinations of the organisms, the patient also frequently provides “evidence” of the parasitic infection in the form of clothing lint, skin crusts, or other debris, the so-called “matchbox sign”11 (these items are collected in a matchbox to be presented to the physicians), which is delusionally misinterpreted as entire organisms, body parts, larvae, or ova. Skin manifestations can be quite variable, if present. Lesions ranging from mild excoriations (Fig. 104-1A) to large ulcers may reflect patients’ unsuccessful attempts at treating the perceived infestation.12 Because this is a monosymptomatic delusional disorder, some patients have a well-organized train of thought and normal outward appearance and behavior, resulting in the conviction by those surrounding them that the subject has a true infestation. The delusion becomes apparent to the physician when the subject is approached.

Differential Diagnosis

Actual infestation and underlying skin or systemic disorders must be ruled out (see Box 104-2). Subsequently, the differential diagnosis of psychosis must be considered, distinguishing between the primary psychiatric conditions that manifest with delusions of infestation. True monosymptomatic hypochondriasis represents a form of delusional disorder characterized by a discrete, circumscribed delusional belief with possible associated hallucinations without clear syndromic changes in affect or personality.7 On the contrary, patients with uni- or bipolar depressive psychosis will describe predominantly classic changes in mood, motivations, sleep, and appetite. Schizophrenic patients may have a history of previous psychotic episodes and often show deterioration in global functioning, impaired social relatedness, thought disorder, paranoid traits, and more bizarre and extensive delusions and hallucinations. In arriving at the diagnosis, it is critical that the clinician differentiate true delusions of parasitosis from formication, which involves the cutaneous sensation of crawling, biting and stinging, but lacks the fixed unshakeable conception that the skin sensations are induced by parasites.

Prognosis and Clinical Course

Although often regarded as chronic, unremitting, and difficult to treat, these patients have an improved recovery rate following appropriate pharmacologic therapy.

Treatment

The critical tenet of treatment is to keep the patient engaged. Empathetic listening, statements of concern, and examinations of the material that patients brings in help to establish rapport. Because these patients will frequently reject psychiatric referrals,13 various authors have suggested means of increasing trust, thus paving the road towards psychiatric evaluation.13,14 It is critical that the dermatologist avoids confronting the patient directly, and exhibits interest in the chief complaint patiently. After a few visits, the physician may carefully introduce the notion that the parasites may not be present, or that the patient is so distressed by this condition, that the prescription of psychotropic medication could be warranted. Targeted therapy is undertaken with antipsychotic medications (Fig. 104-1B).15 Pimozide has been used historically as the drug of choice,16,17 although it is now being replaced by atypical antipsychotics, which are associated with a more favorable side effect profile (eBox 104-2.1).14,18 The clinician needs to be aware of the need for monitoring for metabolic syndrome characterized by abdominal obesity, insulin resistance and impaired glucose tolerance, disturbance in lipid metabolism, hypertension, and weight gain. In many instances, the psychotropic medication needs to be introduced by the dermatologist, and only when the patient begins to respond favorably is it possible to obtain a referral to a psychiatrist.

This group of syndromes is characterized by self-inflicted dermatological disease; they are mostly differentiated based on the degree of insight or consciousness of their behavior.

Dermatitis Artefacta

Dermatitis artefacta is a form of factitious disorder in which patients intentionally feign symptoms and produce signs of disease in an attempt to assume the patient role.6 Unlike patients with malingering who engage in similar behavior for external or “secondary gain” (such as monetary reward or relief from occupational or other social responsibilities), the factitious patient seeks the “primary gain” of the emotional and psychological benefits that accrue to those who are “ill.” Patients with borderline personality disorder also frequently exhibit self-mutilatory behavior19 as do patients who consume cocaine or methamphetamine. However, their reasons for self-mutilation are variable, and are not usually consistent with efforts for primary or secondary gain. Occasionally, a psychologically disturbed adult will induce skin lesions in their children.20

Epidemiology

Predominating in females, the age of onset varies significantly from adolescence through adulthood.21 Comorbid depressive and personality disorders may also be seen coexisting with this rare syndrome.6

Clinical Findings

Although it has long been observed that patients with dermatitis artefacta may present with lesions in virtually all areas of the body that can mimic most dermatoses, some common elements may hint at this diagnosis. Lesions are often in areas readily accessible to the patient, and may have geometric patterns or angulated borders surrounded by completely healthy skin. Morphology is often bizarre and does not conform to typical presentations of known dermatoses (Figs. 104-2 and 104-3). Patients are often unable to provide a clear history of the initial appearance or evolution of the process, typically deny any role in the production of the lesions, and may self-induce the lesions in a dissociated state.22 Characteristically, the histopathology is unrevealing.

Differential Diagnosis

As in all cases of factitious disease, the clinician must rule out possible disease entities that are consistent with the history and clinical findings. Unusual presentations of common illnesses and rare conditions must be entertained. However, exhaustive searches for primary skin pathology without supporting clinical evidence may compound the problem and actually perpetuate the patient's factitious behavior. Occlusive dressings (e.g., an Unna boot) or other means of preventing manipulation by the patient lead to healing of the lesions and are often helpful strategies in clarifying the diagnosis.

Treatment

A supportive, nonconfrontational, empathic approach to the patient is indicated initially. Immediate confrontation regarding the suspicion that the patient's lesions are self-induced can be counterproductive in that the patient often flees from treatment. Frequent visits and symptomatic topical treatments are initially useful.23 However, the clinician must be careful not to collude in the patient's abnormal illness behavior. Ultimately, the recognition of the patient's role in the production of the lesions must be broached. The goal is to establish a trusting relationship such that the patient will accept a psychiatric referral. Antidepressants (eBox 104-2.2) and low-dose atypical antipsychotics (eBox 104-2.1) have been reported to be useful adjunctive therapies.24,25 In the case of inflicted lesions in a child protective services or equivalent agencies must be alerted immediately to safeguard the welfare of the child.

Course and Prognosis

These are fundamentally determined by the underlying psychopathology. In those patients with severely disturbed personalities, the recurrent self-defeating and destructive behaviors are likely to continue.

Dermatitis Para-Artefacta Syndrome

These are a group of factitious diseases, where problems of impulse control play a significant role; the patients are conscious or semiconscious of manipulating their skin, but are unable to stop this behavior.

Trichotillomania is an impulse control disorder,7 characterized by repetitive pulling of hair, resulting in alopecia. Strict criteria also include a build up of tension before hair pulling or when resisting an urge to do so, pleasure or relief after pulling out the hair, and significant functional impairment and distress in the patient.

Epidemiology

Prevalence rates are estimated to be between 0.5% and 3.5% with a mean age of onset between 10 and 13 years. Despite its current classification, there are marked similarities with obsessive-compulsive disorder (OCD), which may have important treatment implications.26–28 Comorbid psychiatric disorders are depression, anxiety, and OCD.

Clinical Findings

Trichotillomania presents clinically with nonscarring alopecia, most commonly with hairs broken at different lengths, normal overall hair density (Fig. 104-4), and a negative pull test29; occasionally, repeated trauma may result in some scarring. Body areas involved typically include the scalp, eyelashes, eyebrows, and pubic hair, with a majority of patients pulling hair from more than one site. Rarely, this is followed by the ingestion of the hair, leading to the potentially dangerous complication of trichobezoar.30 Awareness of the behavior is partial to complete in a vast majority of patients, and frequently occurs while patients are engaged in isolated, sedentary activities. Attempts to resist the behavior and to disguise its cosmetic sequelae are common. Typical histopathologic findings that may be helpful in confirming the diagnosis in questionable cases include catagen and telogen hairs, pigment casts, and traumatized hair bulbs without significant inflammation or scarring.31 Perifollicular hemorrhage near the hair bulb is diagnostic.

Differential Diagnosis

When patients do not have awareness of pulling their own hair and present with alopecia, other etiologies of hair loss must be ruled out.

Treatment

Because of trichotillomania's similarities to OCD, the use of selective serotonin reuptake inhibitors (SSRIs) and clomipramine, as well as combinations with atypical antipsychotics have received much attention (eBoxes 104-2.1 and 104-2.2).28,32–37 However, psychopharmacologic data have been conflicting, and the best-designed studies have not demonstrated superiority of psychotropics over nonpharmacologic interventions. Nonpharmacologic treatment of trichotillomania relies heavily upon behavioral therapies, especially habit reversal, which entails engaging the patient in a behavior incompatible with hair pulling when the urge appears. The addition of cognitive-behavioral or insight-oriented psychotherapy have good results; hypnotherapy may also be very useful, particularly in children.38

Prognosis and Clinical Course

Trichotillomania is a chronic disorder and data on long-term success of pharmacologic and psychotherapeutic interventions are inconclusive. Though children typically have a benign course, adult-onset trichotillomania is often associated with other psychiatric conditions and sustained improvement has yet to be shown convincingly.

Skin Picking (Neurotic Excoriations)

This is also a condition in which patients induce skin lesions through repetitive, compulsive excoriation of their skin. However, unlike patients with dermatitis artefacta syndrome, these patients admit their role in the production of the lesions.

Epidemiology

This is the most common psycho-cutaneous disorder, reported in up to 2% of dermatology clinic patients39 with a predominance in middle-aged females, and are frequently associated with compulsivity–impulsivity spectrum and mood disorders.40,41

Clinical Findings

Patients with skin picking often describe significant itch leading to persistent scratching, which is frequently antedated by considerable psychological stressors. The development of this disorder has also been noted to be associated with the marked limitation in activity seen in illness or senescence.42 The repeated excoriation can lead to the development of an “itch–scratch cycle,” perpetuating the behavior. Patients present with multiple excoriations in various stages of evolution and healing, with postinflammatory hyperpigmentation and frequent scarring (Fig. 104-5). The distribution of the lesions reflects their self-inflicted nature with most being on the extensor surfaces of the extremities, upper back, and face, sparing unreachable areas such as the central mid-upper back. Frequently, patients develop excoriations overlying preexisting dermatosis, such as folliculitis and acne; excessive manipulation of the latter leads to the condition known as “acne excorieé”. These patients often spend many hours each day in front of the mirror injuring the skin with instruments such as tweezers. The trauma often results in temporary relief of anxiety. Prurigo nodularis can be considered an extreme variant of this entity, characterized by severely pruritic nodules varying from a few millimeters to 1–2 cm in diameter, preferentially located on the extremities (Fig. 104-6) (see also Chapter 15).

Differential Diagnosis

The clinician must evaluate the patient for causes of pruritus (see Chapter 103) and rule out possible internal diseases including neoplasms, in particular, lymphomas. The differential for the underlying psychiatric disorder,43 if present, must include depressive and anxiety disorders and, more rarely, excoriations secondary to delusions of parasitosis.

Treatment

Work-up for pruritus should be instituted in those patients that present significant itch. In the absence of organic cause, these patients may improve with phototherapy. Additional treatment should be directed at underlying psychopathology when identifiable. Antidepressants, helpful in both depressive and anxiety disorders including OCD,44 are very useful. Subsequent addition of low-dose atypical antipsychotics has been found effective. Supportive psychotherapeutic approaches and behavioral interventions as those used to treat self-injurious behaviors in Tourette's syndrome may be helpful.45

Course and Prognosis

This can be a chronic condition whose prognosis depends on the underlying psychiatric illness.46 With appropriate therapy, patients with affective and anxiety disorders may have excellent outcomes, with a symptom-free, normally functioning state.

Malingering

Malingerers intentionally induce skin lesions in order to obtain secondary gains, often workman's compensation or disability. Since there is no patient motivation for therapy, treatment is not possible.6,47

This is a group of heterogeneous disorders where the patients complain of a variety of symptoms that cannot be objectively verified by the physician, but they share similar psychiatric underlying problematics.

Body Dysmorphic Disorder

BDD is a chronic condition characterized by an excessive preoccupation or concern with a presumed defect in physical appearance despite normal or minimally objective anomalous findings.48 Also known as dysmorphophobia,49,50 this is a psychological experience that also results in functional impairment, poor quality of life, and low treatment response.

The nosological classification of BDD revolves around the intensity with which patients hold on to their abnormal beliefs. Those with unshakeable convictions are currently diagnosed as having a delusional disorder.7 However, there appears to be a continuum of intensity and insight from preoccupations, through overvalued ideas to clear delusions.51 Those patients that retain a certain degree of insight evidence characteristics more similar to the obsessive–compulsive spectrum of disorders,51,52 a finding that has significant potential treatment implications. BDD patients have obsessive thoughts about their “flaws” and engage in compulsive behaviors related to how they perceive their appearance, similar to behavior seen in obsessive–compulsive disorder.53

Epidemiology

The prevalence of BDD, is estimated to be from 0.7% to 2.4% in the general population to 12% in dermatology clinic patients, often in association with mood disorders such as major depressive disorder (MDD) (37%), social phobia (33%) and OCD (26%).54,55 Improvement of MDD and BDD seems to be closely related, with the improvement of each disorder significantly predicting the remission of the other. Improvement of OCD significantly predicts remission of BDD, but not vice versa. Approximately 80% of patients report a history of suicidal ideation and 24%–28% have attempted suicide.56–58

Clinical Findings

Patients present with intensely articulated distress about various body parts. Most patients also develop ideas of reference in which they think or are convinced that others notice and comment upon the presumed defect. Time-consuming, compulsive behaviors often accompany the worrisome thoughts, including repeated examination in mirrors, covering up defects, and asking others for reassurance. Consultations with other physicians and past operations on the perceived defect are common. Marked restriction in social and occupational functioning is seen in up to 98% of individuals, and 30% of patients have been described as housebound.59 Thoughts and attempts of suicide are frequent. Thus, current or past suicidal ideation should be routinely assessed by the practitioner. Particular monitoring may be needed with younger patients as antidepressant action may increase impulsivity and likelihood of suicidal attempts.58

Treatment

Many patients with BDD will seek dermatologic or surgical treatment over the course of their illness. Evidence suggests that if patients receive such treatment they do not improve, are usually disappointed with the results, and may even experience an exacerbation of their symptoms. It is strongly recommended that cosmetic lines of treatment be avoided. BDD is a severe and complex disorder that often requires multimodal treatment using cognitive behavioral therapy (including exposure response prevention) and medication.60,61

Pharmacologic trials show a good response to SSRIs (see eBox 104-2.2), improving insight while decreasing distress, compulsions, and frequency and intensity of obsessions about perceived defects. Interestingly, SSRIs appear equally effective for delusional as well as nondelusional patients. Efficacy usually requires 12–16 weeks of relatively high dosages. Issues of compliance require close monitoring, since they are a frequent cause of treatment failure. A significant proportion of patients who fail one adequate SSRI trial respond favorably to a second SSRI, suggesting that serial trials of similarly acting agents should be administered in initially refractory cases. Lack of clear success has been noted with other agents such as antipsychotics, tricyclic antidepressants (TSA) (other than clomipramine), benzodiazepines, and anticonvulsants.62–67 Similar to patients with OCD, cognitive-behavioral therapy is strongly recommended.

Prognosis and Clinical Course

BDD is a chronic illness without clear evidence for spontaneous remission without treatment. Pharmacotherapy with appropriate medications may lead to improvement in a considerable number of patients. However, effective doses of SSRIs are usually beyond those approved by the FDA; the data also indicate high recurrence rates with discontinuation of treatment.64 Thus patients may require long-term treatment, including adjunctive insight oriented psychotherapy.57,60

Somatization Disorder

These patients present to the physician with multiple significant physical complaints and the belief that their symptoms are due mostly to exposure to environmental causes. This disorder includes Gulf War syndrome, multiple chemical sensitivity syndrome, amalgam related syndrome, chemical or detergent allergies, “sick building syndrome,” food intolerances, and “candida hypersensitivity syndrome,” among many others. There is no medical proof of a direct causal relationship between exposure and the extent of complaints. The widespread dissemination of information through the Internet as well as the insistence of self-proclaimed experts reinforces the patients’ misinterpreted beliefs.

Hypochondriacal Disorders

Typically these patients express the conviction or fear of suffering from a serious illness (such as AIDS, venereal diseases or cancer) despite the lack of medical evidence.

Cutaneous Dysesthesias (Atypical Chronic Pain/Burn Syndrome)

Occasionally, patients will present to dermatologists with complaints of burning, pain, or dysesthesias in the skin or mucus membranes for which no identifiable pathology can be found. This can be a frustrating situation for patient and clinician alike. A psychiatric approach to these patients may offer a means of understanding the complex factors underlying this syndrome, such as comorbid affective disorders, personality vulnerabilities, behavioral problems, and life circumstances that may perpetuate the pain cycle and maintain the patient in an illness role.

There is a significantly increased rate of depression in patients with chronic pain syndromes and a clear relationship between lifetime depression and the development of medically unexplained symptoms, including pain.68 Depression not only worsens the experience of pain by psychologically magnifying negative perceptions, but may also interfere with the function of descending monoaminergic neurons that dampen nociceptive transmission.69,70 Other complicating factors include anxiety, which is also commonly seen in patients with chronic pain.68 Personality disorders influence all aspects of patients’ lives and may make the burden of a chronic condition more challenging. At times, family or social environments may unwittingly play a role in undermining the chronic pain patient's rehabilitation by rewarding illness behaviors with well-meaning, yet oversolicitous, attention. Pain states can further be complicated if the patient develops an inappropriate pattern of using prescribed analgesics. For all of these reasons, the best course of action for patients presenting with poorly explained chronic pain is to refer them to a multidisciplinary pain center for thorough evaluation and treatment. The presence of burn syndrome may occasionally respond to the administration of gabapentin (see eBox 104-2.2). Milnacipran, an SNRI approved for fibromyalgia (eBox 104-2.2), also may be effective for chronic pain/burn/dysesthesia syndrome. Extreme forms of chronic dysesthesia can resolve with the administration of antipsychotic medication, suggesting that it represents a form of delusion.

Psychogenic Pruritus

Psychogenic pruritus and itch in general are discussed in Chapter 103.

These include dermatological findings that are the result of disorders such as compulsive washing (xerosis, eczema) or rubbing (lichen simplex chronicus). OCD is also related to BDD as well as some factitious conditions such as trichotillomania or skin picking (see above).

Dermatologists who elect to treat psychocutaneous disorders routinely use a number of different classes of psychotropic medications. Knowledge of the drugs and their actions, indications, side effects, therapeutic doses, and potential drug interactions is critical.71 These drugs are classified according to their clinical utility (e.g., antidepressants or antipsychotics) and further identified by their chemical structure and/or mechanism of action. All of the drugs discussed in this section exert their clinical effects through modulation of neurotransmitter function in the CNS by altering presynaptic reuptake of the transmitters, blocking their pre- and/or postsynaptic receptor binding, stimulating those receptors, or some combination thereof. The most appropriately used in each of the following three major classes are discussed: antipsychotics, antidepressants, and anxiolytics.

For a detailed discussion of these drugs, their side effects, and precautions, see online edition of the book.

Antipsychotics

Complications

Antidepressants

Tricyclic Antidepressants (TCAs)

Dosing

Complications

Selective Serotonin Reuptake Inhibitors

Dosing

Complications

Serotonin and Norepinephrine Reuptake Inhibitors

Anxiolytics

Dosage

The dermatologist should request a consultation with a psychiatrist or a liaison clinic during the treatment of patients with psychocutaneous disorders as soon as it is amenable to the patient. Although dermatologists are becoming more comfortable with the use of certain psychotropic medications, they generally do not have the time or the training to use effectively nonpharmacologic modalities. Therefore, it is sufficient that the practicing dermatologist be aware that a variety of adjunctive, stress-reducing approaches are available, including hypnosis, biofeedback, progressive muscle relaxation, and psychotherapy (Box 104-3). Although no modality has been demonstrated to be superior to another, certain types of therapies may be more effective for a given condition. Diagnosis should drive choice of therapy.