Synonyms: neurotic or psychogenic excoriation, pathological or compulsive skin picking, dermatotillomania.

Excessive scratching or picking of normal skin or of skin with minor surface irregularities can result in severe and prolonged acne, with an exacerbation of underlying inflammatory processes and scarring.

Epidemiology¹

• It is seen in about 2% of dermatology clinic patients.²
• One study using a community-based questionnaire found that 62.7% of 354 respondents confirmed some form of skin picking and 5.4% reported clinical levels of skin picking and associated distress/impact.³
• It is more commonly seen in women.
• The mean age of onset is in middle-age (30-45 years).
• It is the most common factitial skin disease of childhood.⁴
• Psychological co-morbidities are common (for example: depression, anxiety, obsessive-compulsive disorder, body dysmorphic syndrome, eating disorders, kleptomania, obsessive-compulsive or borderline personality disorders).²

Presentation⁵

• Most of the lesions are excoriated papules with few obvious comedones and papules. Erosions can become frank ulcers.
• Lesions occur where the patient can scratch: face, trunk, extensor extremities and upper back.
• There is usually a bilateral distribution, with a tendency for more lesions on the left in right-handed individuals and on the right in left-handers.
• Scars tends to be:
  • Round, oval or stellate in shape
  • Hypo- or hyper-pigmented
  • With angulated borders
  • Approximately the same size and shape

Differential diagnosis¹

• Scabies
• Dermatitis herpetiformis
• Renal disease and uraemia
• Cocaine/opiate/amfetamine use
• Lymphoma
• Diabetes mellitus
• Thyroid disease
• Iron deficiency
• Delusions of parasitosis
• Dermatitis artefacta.

Primary care management

• Trial of systemic antibiotics for 6 months as for acne vulgaris but frequently response is poor.
• Always consider diagnosis in acne not responding to treatment, atypical presentations and where scarring is predominant.

When to refer

• Refer to dermatology where treatment with retinoids is required. Note that relapse following roaccutane therapy is common.
• Refer to psychiatry for consideration of medication (including SSRIs and neuroleptics such as olanzapine), psychological therapies (cognitive-behavioural therapy, habit reversal) and hypnosis.^2,6

Complications

• Scarring
• Worsening anxiety

Prognosis

The condition has a tendency to become chronic although improvement can occur with treatment of underlying psychological illness.