Obsessive-compulsive disorder (OCD) can present in as many as a quarter of patients in dermatology clinics, the ACD ASM was told.
Professor Chee Ng, Healthscope Chair of Psychiatry at the University of Melbourne, said body-focused repetitive behaviours such as excoriation disorder and trichotillomania could lead to significant distress, shame and embarrassment.
He said repeated picking of the skin especially of the face, neck, cuticles, back and limbs was a way of coping with negative emotions, stress and tension.
Unfortunately, the relief was often followed by shame, guilt and secondary depression. Physically, the behaviours could result in scars and mild to severe pain.
“They are likely to have OCD and other body-focused repetitive behaviours such as nail biting.”
He said repeated hair pulling, not caused by other conditions, also led to significant distress.
Onset was usually in childhood or adolescence and affected hair on the scalp and eyebrows, and later, the beard and pubic hair.
Triggers for the behaviour could include exams, financial stress and work stress.
Professor Ng encouraged dermatologists to make a diagnosis using tools such as the clinician-rated Yale-Brown Obsessive Compulsive Scale (YBOCS) and the patient- reported Obsessive-Compulsive Inventory (OCI-R).
Evidence-based treatments included cognitive-behavioural therapy (CBT), habit reversal therapy, exposure and response prevention and acceptance.
Given the high comorbidity with anxiety and depression, pharmacotherapy – balancing tolerability and efficacy – was also useful.
“Clomipramine and SSRIs are most effective in combination with psychological therapies,” Professor Ng said.
When initial treatments did not appear to be effective, he suggested referring to a psychiatrist, trialing an increased dose and considering other agents.
Other skin-psych overlaps
Professor Ng said the relationship between the acne treatment isotretinoin and depression remained controversial.
A 2019 meta-analysis found overall isotretinoin was not related to depression except when only retrospective, but not prospective studies, were included. None of the included studies were randomised controlled trials.
Professor Ng also added that delusional parasitosis was a notoriously difficult condition to treat given the patients’ lack of insight and reluctance to present for treatment.
However if it wasn’t adequate managed early, it could become chronic.
Close collaboration with a GP, dermatologist and psychiatrist was probably the best way forward.
Unfortunately, patients sometimes presented to the ED with severe mutilation and may then be forced into psychiatric care.