The finding: There a number of interventions that have shown evidence of benefit in treating excoriation disorder (ExD), though to date, there has been no systematic review of these studies. The authors undertook this systematic review and meta-analysis to examine the efficacy of treatments for ExD and identify clear treatment recommendations. A total of 12 studies were reviewed, of which 9 were randomized controlled trials and were included in the meta-analysis. The systematic review found strong effect sizes for the SSRIs, fluoxetine in particular, lamotrigine, and behavioral therapy. However, the meta-analysis’ results were not quite so robust, with small-moderate effect sizes without any one treatment approach being superior. Subjects’ self-reported level of impairment improved less than their perceived severity of symptoms. The authors also suggest, based on their analyses and their own review of the literature, that behavioral therapy may be the first-line treatment for ExD.

Strengths and weaknesses: This is the first study of its kind examining treatments for ExD and in this it is a good review of the efficacy of various treatments. However, this investigation also highlighted the relative lack of studies in this area, specifically RCTs. The studies included in this analysis had small sample sizes and a lack of heterogeneity that limited the ability to elucidate moderators and allow a comparison of efficacy of the different treatments. In addition, the study’s use of the fixed effects model limited the generalizability of the findings beyond the studies themselves.

Relevance: It is helpful for the PM psychiatrist to be aware of the different treatments that may be effective for ExD, and that behavioral treatments have demonstrated a strong benefit.

The finding: The study investigators hypothesized that N-acetylcysteine (NAC), a prodrug of the amino acid cysteine, would be more efficacious than placebo in treating the symptoms of skin picking disorder (SPD). Previous research with trichotillomania (TTM), a disorder with strong links to SPD, suggested efficacy. NAC may work to decrease the synaptic release of glutamate in the nucleus accumbens, which has been implicated in compulsive and habitual behaviors. Subjects were randomized to either NAC or placebo, which they received over a 12 week period. The NAC dose was increased twice over this period, to a total dose of 3000 mg. The results demonstrated a significant improvement in NE-YBOCS total score and the urge/thought subscale as well as CGI severity scores. However, there was no significant difference from placebo in regard to psychosocial functioning or quality of life.

Strengths and weaknesses: This is a novel treatment for SPD that showed efficacy in prior studies with TTM. Strengths of the study include randomization and blinding though the authors pointed out that the sulphurous smell of NAC may have compromised the blinding. The results are limited by the study’s relatively small sample size. Additionally, the study investigators suggested that the length of the study may not have been sufficiently long enough to observe a significant improvement in some of the subjects. It is also possible that some study participants may have responded to a higher dose of NAC.

Relevance: Given the limited evidence for effective treatments for SPD, this study offers a possible alternative that may provide benefit.

The finding: This is a cross-sectional study comparing the severity of anxiety sensitivity (AS), defined as the fear of anxiety symptoms due to the perception of harmful social, cognitive, or physical consequences in subjects with psychodermatological conditions, such as psoriasis and acne, to patients with a nonpsychodermatological condition, like skin cancer. The authors cite previous research that found AS to be a vulnerability factor that may contribute to the development, exacerbation, and maintenance of many different psychological and chronic health conditions. Based on the observation that stress plays a role in the onset and exacerbation of dermatological conditions, they posit that high AS may increase anxiety and worsen the severity of skin disorders. The results confirmed the hypothesis that individuals with psychodermatologial conditions would have higher AS scores compared to subjects with nonpsychodermatological conditions. Specifically, participants with a psychodermatological disorder had higher scores on the Anxiety Sensitivity Index-3 (ASI-3) total and the social and cognitive subscales. However, after adjusting for general anxiety symptoms, only the social subscale of the ASI-3 was significant in predicting the subject had a psychodermatological condition.

Strengths and weaknesses: This is the first study to examine AS in psychodermatological disorders and highlights the potential role of anxiety and stress in the development and exacerbation of certain skin disorders. Weaknesses include its cross-sectional study design and small sample size. It is also questionable whether the consideration of AS is more valid and useful than the assessment of general anxiety symptoms, particularly when the treatment would be the same.

Relevance: This study highlights the importance of screening for anxiety symptoms in patients with dermatological conditions.