Obsessive-compulsive skin disorders

ICD-11

6B20.Z

Synonyms

Obsessive–compulsive neurotic skin disorders.

Epidemiology

Estimated prevalence in adults: 2.3%. Age of onset: 19.5 years.
Persistent disorder for years (mean of 8.9 years).

Excoriation disorder: 1-5% of the population. Female preponderance.
Onset at adolescence (most common), or adulthood (30 -45 years of age).

Body-focused repetitive behavior disorder. Prevalence onychophagia (nail biting): 25-60%.

Definition

Group of dermatoses secondary to a chronic psychiatric disorder characterized by obsessions and compulsions.

Excoriation disorder (neurotic excoriations): Repetitive picking of skin resulting in noticeable tissue damage.

Body-focused repetitive behaviors: onychophagia, dermatophagia, onychotillomania (nail picking), trichotillomania, cheek/lip biting, nose/ear picking, and knuckle cracking.

Aetiology & Pathogenesis

Obsessive-compulsive and related disorders is a category of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).

Body-focused repetitive behaviors are included under ‘‘unspecified OCRD’’ in DSM-5.

Some OC related-skin and hair disorders, such as trichotillomania (see chapter 7.2.1)

Signs & Symptoms

Excoriation disorders:

-Grouped erosions at easily accessible sites. Picking over areas of acne, scars, scabs, or insect bites.

-Acne excoriee: Acne lesions are scratched and picked.

Body-focused repetitive behavior disorder. Variable clinical features such as:

Nail biting: paronychia and gingival injuries.

Rubbing of the proximal nail fold: nail matrix damage.

Chronic biting of the skin: localized thickened plaques (lichenification).

Cheek biting: transverse whitish ridges in the oral mucosa (morsicatio buccorum).

Repeated attempts to decrease or stop skin picking
Associated psychopathology (depression, anxiety, or stress).

Localisation

Acne excoriee: frequent facial involvement.

Body-focused repetitive behavior disorder: nails, fingers, oral mucosa, lips. Accessible skin areas.

Classification

Secondary infection, bleeding, and inflammation.

Laboratory & other workups

No abnormalities.

Dermatopathology

Cutaneous ulceration without or minor associated inflammatory infiltrates.

Course

Chronic. Waxing and waning evolution.

Diagnosis

DSM-5 diagnostic criteria.

Differential diagnosis

Psychogenic pruritus. Primary psychiatric disorders with secondary excoriations (e.g. delusional infestation or tactile hallucinations).

Skin picking secondary to the physiological effects of a substance (e.g. cocaine) or a medical condition (e.g. scabies).

The differential diagnosis of cheek biting includes oral candidiasis, lichen planus and white sponge nevus.

In nail biting: nail dystrophy, nail matrix damage and mycotic infections.

Prevention & Therapy

Cognitive-behavioral therapy (CBT) and habit reversal training.

Anti-depressive and anti-psychotic agents are helpful by treating underlying anxiety.

N-acetylcysteine 1200 to 3000 mg/ day may reduce skin picking.

In patients with acne excoriee: Additional appropriate acne treatment.

Special

Approximately 90% of individuals with OCD have other psychiatric co-morbidities. The most common co-morbid disorder in OCD is anxiety disorders, depression, impulse control and substance use disorders. The co-morbidity of OCD and depression significantly increases the risk of suicide.

7.2.4 Obsessive-compulsive skin disorders