Psychodermatology

Trichotillomania

Trichotillomania is a compulsive urge to pull out one’s own hair. It clinically looks like patchy hair loss that does not follow anatomic or physiologic landmarks. The scalp is most commonly affected, but other areas can be involved. On dermoscopy the most common findings are decreased hair density, broken hairs at different lengths, trichoptilosis (split ends), irregular coiled hairs, upright regrown hairs, and black dots showing perifollicular hemorrhages. Malakar and Mukherjee described a dermoscopy finding of a dark bulbar proximal tip with a linear stem of variable lengths looking like a burnt matchstick. Trauma and traction cause this finding.

Unlike innocent hair pulling, which occurs commonly in toddlers and preschoolers, children with trichotillomania demonstrate obsessive-compulsive symptoms.

The Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) describes trichotillomania as an impulse control disorder affecting 1.5–2% of the general population. In adults there is a female-to-male ratio of 4:1; however, in children, girls and boys are equally affected and severity is variable. Observational data show that one-third of affected children have comorbid psychiatric conditions including generalized anxiety, social phobia, major depression, substance-use disorders, attention-deficit/hyperactive disorder, and oppositional defiant disorder.

Trichotillomania differs from other obsessive-compulsive disorders (OCDs) as age of onset is usually early adolescence rather than late adolescence, and individuals with trichotillomania do not have intrusive thoughts like in other OCDs. There are often other repetitive motor symptoms such as skin picking and nail biting. Psychotherapy evidence supports cognitive behavioral therapy, focusing on habit-reversal training, where the emphasis is on replacing hair pulling with more desirable behaviors.

A glutamatergic agent, N-acetyl cysteine, has been found to reduce urges. Olanzapine has also been shown to be effective. There is no evidence that selective serotonin reuptake inhibitors (SSRIs) are beneficial. Trichotillomania is not self-limited and requires long-term psychiatric and medical therapy (see Fig. 8.24 ).

Delusions of parasitosis

Delusions of parasitosis, the most common monosymptomatic hypochondriacal psychosis treated by dermatologists, occurs when an individual is convinced that the skin is infested with imaginary mites, worms, or insects. Cutaneous findings range from none to excoriations, lichenification, prurigo nodularis, and ulcerations, which are created by the patient attempting to dig out the parasites. Patients may also present with collections of scale, hair, and/or other debris presumably containing parasites ( Fig. 11.1 ). Other delusional disorders include bromosis (foul odor) and dysmorphosis (abnormal or ugly appearance).

These patients have little insight into their disease and usually refuse consultation with psychiatrists. Unfortunately, the prognosis is guarded, and symptoms may persist indefinitely. Small case studies of delusions of parasitosis showed symptom improvement with pimozide at a dose from 1 to 5 mg daily for 6 weeks before starting to taper and olanzapine at 5 mg daily for 10 weeks, sometimes increasing to 10 mg daily.

Concurrent medications may be beneficial, including anxiolytics, antidepressants, and corticosteroid creams. Aripiprazole, a third-generation antipsychotic, is another potentially safe and effective option.

Skin picking disorders

Skin picking disorders and other body-focused repetitive behavior disorders (BFRBD) have been introduced in the DSM-5. These disorders can be expressed in multigenerational families and may have comorbid associations.

In acne excoriée and skin picking, variants of OCDs, patients pick and gouge trivial acne or other skin lesions on the face, arms, or hands, but often at multiple sites, resulting in erosions and ulcerations that may heal with scarring ( Fig. 11.2 ). Acne excoriée occurs most commonly in adolescents. This disorder is triggered by emotional states such as anxiety or boredom. There are two subgroups: those with primary acne and those with no primary lesions. Patients may attempt to stop picking, and acne treatment, when appropriate, is the first line of treatment. Cognitive behavioral therapy, habit reversal training, and N-acetyl cysteine have been shown to have good results. SSRIs and/or low-dose antipsychotics have also been used with variable responses.

A subset of patients with self-induced skin lesions, often referred to as factitious disorders, usually adolescents, develop cutaneous findings such as coining, excoriations, and chemical burns in association with situational stress ( Figs. 11.3–11.5 ). Disordered family dynamics, sexual abuse, school phobia, lost love, and other acute or chronic psychosocial problems may result in this form of attention-seeking behavior. When this diagnosis is suspected, lesions may be covered with occlusive dressings for several weeks to see if healing occurs. When confronted, the patients usually admit to the self-injurious behavior. Counseling and improvement in the situation often result in an end to the lesions.