The skin is the largest organ of the body, and skin disease is unique in often being immediately visible to others. This is one reason why dermatologic disease is accompanied by significant psychological distress and psychiatric morbidity.1,2
Many dermatologic disorders are associated with negative quality of life, and psychiatric disturbances are reported in at least 30% of these patients.2,3 There are many reasons for the elevated frequency of psychiatric disturbance in dermatologic patients, including disfigurement, perceived social stigma, and unforeseen changes in lifestyle. Although less common, the dermatologist may also encounter primary psychiatric disorders, including obsessive-compulsive disorder, trichotillomania, dysmorphophobia, delusions of parasitosis, and factitious disorder. Skin conditions and psychiatric symptoms may be present concomitantly in some illnesses, such as systemic lupus erythematosus or porphyria. And medications utilized in dermatologic practice, such as corticosteroids, may precipitate psychiatric symptoms.
The connection between brain and skin begins in the embryo, when the nervous system and epidermis originate from the same tissue layer (ectoderm). They then maintain close neural, endocrine, and immunologic connections throughout life, including being targets of the same immunologic processes, neurotransmitters, neuropeptides, and second messengers.4,5 It is hypothesized that chemical messengers released by epidermal keratinocytes influence the brain, and this may account for an association between the severity of certain skin diseases (e.g., atopic dermatitis, psoriasis) and depression or anxiety.5 When a large area of skin is involved, cytokine levels may be of sufficient concentration to affect mental state.6
This chapter focuses on the most common dermatologic illnesses associated with depression: acne vulgaris, herpes zoster (HZ) (shingles), psoriasis, vitiligo, and atopic dermatitis (Fig. 12-1).
Mean risk of depression for selected illnesses (percentage prevalence for particular disease).
Acne is very common in adolescence and is strongly associated with depressive symptoms. Acne has an adverse effect on quality of life comparable to that of epilepsy, asthma, diabetes, and arthritis. Although the disorder is self-limited for many, even patients with mild to moderate acne may have significant psychosocial difficulties. Acne can also be severe and disfiguring, with profound and lifelong consequences for a significant number of patients. Sequelae include hypertrophic or pitted scarring, poor body image, interpersonal problems, social withdrawal, higher unemployment rates, lower self-esteem, depression, anxiety, suicidal ideation, and suicide. Further complicating care, acne is exacerbated by emotional and psychosocial stress and associated with major depression.7,8
Facial acne has an overall prevalence of 54%, though most is mild, and clinically significant facial acne is present in 3% of men and 12% of women (Box 12-1).9 It typically begins early in puberty, triggered by hormonal changes. ...