2020 guidelines for the diagnosis and treatment of cutaneous pruritus

Model of Chronic Itch in Aged Mice: Beneficial Effects of Drugs Affecting Descending Modulatory Systems

Pruritus in the elderly, particularly those cases without skin dryness or other identifiable causes, makes treatment challenging due to the lack of evidence regarding the therapeutic effects of antipruritics. This study proposes an age-related alloknesis mouse model for an evaluation system for such cases, and aimed to investigate the effectiveness and mechanisms of action of several drugs commonly used as antipruritics in Japan, utilizing this model. Mice 69-80 weeks old were used as aged mice, and the level of mechanical alloknesis was counted as the number of scratching behaviours in response to innocuous stimuli. Bepotastine, neurotropin, pregabalin, baricitinib, and abrocitinib were used as antipruritics, and yohimbine and methysergide as inhibitors of the descending inhibitory pathway. The findings suggest that mechanical alloknesis in aged mice is a suitable animal model for assessing pruritus in the elderly without xerosis, and pregabalin, neurotropin, baricitinib, and abrocitinib may be effective antipruritics in the elderly through activating both the noradrenergic and serotonergic descending inhibitory pathways. These findings may be useful for the selection of antipruritics for pruritus in the elderly without skin lesions or dryness.

How to handle off-label prescriptions of rupatadine, a second-generation antihistamine and PAF antagonist: a review

The off-label use of second-generation antihistamines, used outside of the formal indications authorized by regulatory authorities, in different age groups, doses or in special populations, is very common for many allergic, autoimmune and dermatological diseases. The off-label use of rupatadine (a second-generation antihistamine with PAF antagonist activity) in these conditions is reviewed here, including in combination with immunotherapy in the treatment of food allergy or allergic rhinitis, at high doses in chronic urticaria, and with prescriptions of less common but challenging conditions such as skin pruritus or mast cell activation disorders like mastocytosis. Rupatadine use is reviewed herein to confirm if its off-label management is supported by well-designed clinical trials or by published real-world cases. This review will contribute to increasing compliance and achieving better results in clinical practice. Off-label use of rupatadine should be left to the discretion of the prescribing healthcare professional after careful clinical evaluation.

The impact of phototherapy on itch intensity and itch-related quality of life amongst different skin diseases, skin phototypes and genders - A prospective study with 102 patients

BACKGROUND

Phototherapy is a mainstay to treat itchy conditions. However, only little is known about differences in the antipruritic effect of phototherapy amongst different skin conditions, phototypes and genders.

METHODS

In this prospective, single-center study, we analyzed the effect of phototherapy on itch intensity and itch-related quality of life amongst these subgroups after a treatment duration of 4 weeks, while on-demand treatment with topical corticosteroids, topical calcineurin inhibitors and/or antihistamines was allowed.

RESULTS

Of 102 patients (age 53.0 ± 18.7, 56 females [54.9%]), 72 (78.3%) reported a significant reduction of itch intensity by Δ -2.76 on a 0-10 Numerical Rating Scale (NRS), p = <.001, 95% CI [2.2; 3.3] paralleled by a significant improvement of itch-related quality of life as measured by the German version of the ItchyQoL by Δ 7.3, p = <.001, 95% CI [4.4; 11.6]. The best improvement of itch intensity and itch-related QoL was reported by patients with pruritus on non-diseased skin (ΔNRS -3.5; Δ 9.7 Ger-ItchyQoL points), followed by patients with atopic dermatitis and psoriasis. We found no statistical differences in the response to phototherapy amongst Fitzpatrick phototypes I-VI. Women had higher itch intensities at baseline but itch-related quality of life impairment at baseline and phototherapy treatment response did not significantly differ between genders.

CONCLUSION

Phototherapy appears to induce a meaningful itch reduction in various itchy skin conditions, all phototypes and both genders within 4 weeks that directly translates into improvement of itch-related quality of life.

Acupuncture for the Treatment of Itch: Peripheral and Central Mechanisms

Despite the widespread clinical use of acupuncture in the treatment of pruritus caused by psoriasis, urticaria, uremic, and other diseases, insights into the mechanism of action of acupuncture are still emerging. For the above reasons, a beneficial effect of acupuncture on pruritus was not recommended or reported in recent clinical practice guidelines. Acupuncture is a kind of physical stimulation, which has the characteristics of multi-channel and multi-target effects. The biomechanical stimulation signal of acupuncture needling can be transformed into bioelectric and chemical signals; interfere with kinds of cells and nerve fibers in the skin and muscle; alter signaling pathways and transcriptional activity of cells, mediators, and receptors; and result in inhibition of peripheral and central transmission of pruritus. Available mechanistic data give insights into the biological regulation potency of acupuncture for pruritus and provide a basis for more in-depth and comprehensive mechanism research.