Involvement of µ-opioid Receptors and κ-opioid Receptors in Itch-related Scratching Behaviour of Imiquimod-induced Psoriasis-like Dermatitis in Mice

The pathogenesis of psoriatic itch is poorly understood. The aim of this study was to investigate the involvement of opioid receptors in scratching behaviour of imiquimod-induced psoriasis-like dermatitis model mice. Topical application of 5% imiquimod cream to the rostral back skin of mice induced antihistamine-resistant scratching behaviour. The expression of µ-opioid receptor (MOR) protein increased in the epidermis, dorsal root ganglia (DRG) and spinal cord of imiquimod-treated mice. In contrast, the expression of κ-opioid receptor (KOR) protein decreased in the DRG and spinal cord of imiquimod-treated mice, and was undetectable in the epidermis of both groups. Topical or intraperitoneal administration of the MOR antagonist naloxone and oral administration of the centrally acting KOR agonist ICI-199,441 inhibited scratching behaviour, whereas oral administration of the peri-pherally-selective KOR agonist asimadoline did not. These results suggest that peripheral and central MOR and central KOR may be involved in the modulation of scratching behaviour in imiquimod-treated mice.

Dermatologic toxicities associated with EGFR inhibitors: the clinical psychologist's perspective. Impact on health-related quality of life and implications for clinical management of psychological sequelae

Dermatologic toxicities associated with EGFR inhibitors can have a profound impact on patients' health-related quality of life (HRQL) and may interfere with treatment adherence. We interviewed 20 patients and 12 expert clinicians to identify the most bothersome aspects of dermatologic toxicities to better understand the impact on patients' HRQL Patients and expert clinicians reported that dermatologic toxicities have an impact on patients' physical, functional, emotional, and social well-being. Patients identified the physical discomfort as having the most impact on their HRQL, specifically the sensations of pain, burning, and skin sensitivity. Patients experienced worry, frustration, and depression because of their dermatologic symptoms and reported withdrawing from social activities. Cognitive behavioral strategies such as guided imagery and symptom reframing (eg, rash means treatment is working) may provide patients with valuable skills for the management of this physical discomfort. Cognitive behavioral strategies may also be useful in helping patients manage anxiety and depression associated with any changes in their social function caused by skin rash, as well as distress associated with having a cancer diagnosis.

Psychological aspects of drug intolerance

A consecutive unselected series of 50 patients suffering from drug intolerance was evaluated by allergological and psychological tests. We wanted to verify the existence of a correlation between some psychological characteristics (hysteria, depression and Ego Integrity), and some clinical aspects (number and type of episodes, severity and probability of the reactions). We confirmed the prevalence of female sex in these disorders, particularly in middle-aged married women. The mean score of hysteria in the whole sample was lightly higher than normal. Moreover a relevant number of subjects (24%) scored higher than the cut off for clinical depression, with a significant difference in comparison to the overall prevalence of depression in the general population. Finally, the analysis of clinical variables considered in our patients showed that subjects with a history of less serious reactions and unlikely reactions scored higher in depression and hysteria scales. The importance of psychological evaluation of drug intolerance patients is discussed and confirmed.

Dermatological pathomimicry: a form of patient maladjustment

Thirteen patients (eleven female, two male; aged 19-72 years) who mimicked their original dermatological disease by reproducing the original mechanisms of disease or by interfering with therapy were seen over a period of 5 years. Six patients had exacerbations of eczema, four drug reactions, and three non-healing leg ulcers. Exacerbations of dermatological disease were related to the patient's need for a sickness role. This maladjustment responded to positive directive psychotherapy rather than a superficial sympathetic approach which tended to reinforce the maladjustment. Eleven patients admitted their part in actively producing their disease, and the outcome was good. This clinical syndrome appears to be predominantly an opportunist reaction although one patient was depressed and one had early dementia. The syndrome should not be confused with dermatitis artefacta.