Psychoneurocutaneous Medicine

Mohammad Jafferany¹, Paul Pastolero¹, and Katlein França^2,3

¹ Department of Psychiatry, Central Michigan University, Mount Pleasant, MI, USA

² Department of Dermatology & Cutaneous Surgery; Department of Psychiatry & Behavioral Sciences, Institute for Bioethics & Health Policy, University of Miami Miller School of Medicine, Miami, FL, USA

³ Centro Studi per la Ricerca Multidisciplinare e Rigenerativa, Università degli Studi Guglielmo Marconi, Rome, Italy

Introduction

The integumentary system and the nervous system share the same embryonic origin. They both derive from the ectoderm. The ectoderm is the germ layer that differentiates to form the brain, spine, and peripheral nerves of the nervous system, as well as the tooth enamel, epidermis, sweat glands, hair, and nails of the integumentary system [1]. These systems work closely together. The skin is the barrier that protects the internal organs from the external world. Conversely, the intrinsic conditions of the body can be transmitted to the external world through the skin after sensing and integrating environmental cues [2]. It is through these interactions between skin and mind that the study of psychoneurocutaneous medicine arises.

Although a relatively young science, the earliest mentions of psychoneurocutaneous medicine can be found in texts from thousands of years ago. In ancient Greece, Hippocrates (460–377 BCE) mentioned the relationship between the skin and the nervous system. He described people who tore out their hair in response to emotional stress. He also described the association of emotion with dermatological manifestations, such as sweating when fearful. Aristotle (384–322 BCE) theorized that the skin and mind were complementary and inseparable [3]. However, it was only in the last two centuries that this field has been studied in further depth. During the eighteenth century, the English physician Robert Willan (1757–1812) described a patient who believed that there were parasites causing skin damage, although no parasite could be found [3]. This is now known today as delusional parasitosis. Sir William James Erasmus Wilson (1809–1884) also described delusional parasitosis [3]. He also described anxiety and depression associated with hyperhidrosis, further highlighting the interaction between mind and skin. Today, with the creation of associations and academic groups, along with the emerging of subspecialties dedicated exclusively to the study of the psychological impact of skin disorders, psychoneurocutaneous medicine continues to evolve.

A number of subspecialties have been developed today. Pediatric and Geriatric Psychodermatology are subspecialties that focus on the assessment, diagnosis, and comprehensive treatment of their respective patient populations [4, 5]. Trichopsychodermatology is a subspecialty focused on understanding and treating the psychological pathologies related directly and indirectly to hair [6]. Psychodermato‐oncology focuses on the psychological impact of skin cancer and the role of stress in the development of skin cancers [7]. Cosmetic Psychodermatology is a subspecialty developed to evaluate the psychological aspects of patients seeking cosmetic procedures [8]. Tropical psychodermatology is a field that studies the psychosocial and quality of life aspects of tropical skin diseases such as endemic pemphigus foliaceus and different infections caused by fungi, virus, ectoparasites, bacteria, and helminths [9]. Sports psychodermatology is a new emerging subspecialty. It focuses on the psychological impact of skin diseases on athletes [10]. Environmental psychodermatology focuses on the interaction between stressors, skin, and the environment [11]. All of these subspecialties further highlight how far the field of psychodermatology has come.

Psychoneurocutaneous Medicine is a rapidly growing field that encompasses numerous schools of medicine. It involves psychiatry, psychology, neurology, and dermatology. It is an integrative science that studies the interaction between the mind, the nervous system, and the integumentary system [12]. Psychiatry is involved in the study of mental processes and pathological illness. Psychology examines the mind and behavior. Neurology is involved with the nervous system and the diseases that affect it. Dermatology is the study of skin diseases. All these specialties combined provide an integrative approach to the analysis and treatment of psychodermatological pathology. The treatment of psychoneurocutaneous disorders focuses on the management of depression and anxiety associated with dermatological diseases, improving quality of life, managing social isolation, and improving the self‐esteem of patients. This chapter will discuss the characteristics, epidemiology, diagnosis, and management of various psychoneurocutaneous disorders.

Classification of Psychodermatological Diseases

Psychodermatological diseases are divided into different classifications based on the presentation, origin, and system in which the pathology is mainly involved [12]. The classifications are as follows: psychophysiological disorders, psychiatric disorders with dermatological symptoms, dermatological disorders with psychiatric symptoms, and miscellaneous [12].

Psychophysiological disorders are skin diseases that are precipitated or exacerbated by psychological stress [12]. Patients can determine a clear and chronological association between stress and precipitation/exacerbation of the skin disease. Examples of psychophysiological disorders include acne, alopecia areata, atopic dermatitis, psoriasis, psychogenic purpura, rosacea, seborrheic dermatitis, and urticaria (hives).

Psychiatric disorders with dermatological symptoms are defined as diseases of the skin that are self‐inflicted [12]. These disorders are always associated with underlying psychopathology. They are also known as stereotypes of psychodermatological diseases. Examples of psychiatric disorders with dermatological symptoms are body dysmorphic disorder, delusions of parasitosis, eating disorders, factitial dermatitis, neurotic excoriations, obsessive compulsive disorders (OCDs), and trichotillomania.

Dermatological disorders with psychiatric symptoms are defined as the emotional and psychological problems that are a result of having a skin disease [12]. The psychological consequences begin to be more severe than the physical symptoms themselves. The psychological problems can include but are not limited to: depression, anxiety, and social withdrawal. Examples of dermatological disorders with psychiatric symptoms are alopecia areata, albinism, chronic eczema, hemangiomas, ichthyosis, psoriasis, rhinophyma, and vitiligo.

Several other disorders have been described and are grouped under miscellaneous conditions. This includes the dermatological side effects of psychotropic medications; for example, psychogenic purpura syndrome and cutaneous sensory syndrome [12].

Dermatitis Artefacta

Dermatitis Artefacta is a form of factitious disorder. It is defined as self‐induced cutaneous lesions that the patient denies having induced. The lesions are typically bilateral and symmetrical in distribution. They have a propensity to be within easy reach of the dominant hand. Shapes can vary and may present with sharp geometrical or angular borders. Depending on how the lesions are afflicted, they may also present as burns, scars, blisters, ulcers, or purpura. Inflammatory signs such as erythema and edema may be present as well. Various methods to self‐induce these cutaneous lesions include rubbing, scratching, cutting, picking, punching, sucking, biting, or by applying heat, caustics, or dyes. Some patients may even go as far as injecting substances, including feces and blood.

The condition is more common in women than men, with prevalence rates ranging from 3 to 20 times more in women than in men [13]. Reported associated conditions include OCD, borderline personality disorder, depression, psychosis, and mental retardation [14, 15]. Complications of dermatitis artefacta include infection, scar formation, and even malignant transformation of lesions [16].

Management of dermatitis artefacta requires an integrative approach. First, patients should be approached in a supportive, non‐judgmental way. Confrontation with the patient should be avoided. Regular follow‐up should occur for supervision and support even if the lesions are no longer present [13]. A focus on appropriate coping skills, such as the teaching of relaxation techniques, has been shown to be useful [17, 18]. Pharmacological management of antianxiety medications such as selective serotonin reuptake inhibitors (SSRIs) and low‐dose atypical antipsychotics such as olanzapine have also shown to be effective [19].