A combined responder analysis of tradipitant demonstrates significant improvements in itch and disease severity
Atopic dermatitis (AD) is characterized by skin lesions and pruritus not relieved by scratching. The challenge for current therapies is to treat both of these characteristic disease symptoms. Many of the currently available therapies improve AD through clearing of the skin by targeting improvement in lesion severity. Targeting AD improvement through reduction in pruritus remains a significant unmet medical need. Tradipitant, a novel neurokinin-1 receptor antagonist, is a possible therapy that could improve AD through reduction in pruritus.
In this study, we investigated the relation between TRPV3 and warmth-evoked itch in AD. Here, we found a marked upregulation of TRPV3 in AD-lesional skin compared with healthy skin or lesional skin of psoriasis or allergic contact dermatitis.
Imiquimod (IMQ) is a common drug in skin disease treatment. However, the side effects of IMQ occurred frequently, which manifested as erythema, itch, and pain, while the mechanism has not been fully understood. Mast cells have been found at the lesion after IMQ treatment, and MRGPRX2 on mast cells has been proved to induce pseudo-allergic reaction in chronic urticaria, contact dermatitis, and other skin diseases. Whether IMQ related dermatitis is mediated by mast cell degranulation via MrgprB2/MRGPRX2 need to be addressed.
Atopic dermatitis (AD) is characterized by intense itch and recurrent eczematous lesions. Interleukin (IL)-33 is constitutively produced from the structural and lining cells, including skin epithelial cells, which are exposed to the environment. Extracellular IL-33 binds to ST2 on T helper 2 (Th2) cells and various innate immune cells including mast cells, eosinophils and innate lymphoid cells. In AD patients, IL-33 overexpression in the epidermis, infiltration of ST2-positive cells and elevated serum IL-33 levels has been implicated in disease pathogenesis.
Recent findings underscore an important role of IL-31/IL-31RA signalling in pruritus. The novel TH2-derived cytokine interleukin-31 (IL-31) has been implicated in the pathophysiology of atopic dermatitis (AD) and induces pruritus via a synergistic cooperation of dysregulated immune cells and stimulated sensory neurons. In particular, the clinical efficacy of the IL-31RA-targeting antibody nemolizumab in treating itch in atopic dermatitis patients emphasized the importance of the IL-31/IL-31RA pathway.
In conclusion, a risk of swimmer's itch in Denmark was confirmed. PMID: 31453626 [PubMed - as supplied by publisher]
Background: Pruritus, or itch, is associated with a wide variety of conditions, including skin and medical disorders, allergies and infections, and exposure to some medications. In many of these conditions, such as atopic dermatitis, the intense pruritus and associated scratching can result in exacerbation of the disease and a reduced quality of life. The itching sensation is transmitted through afferent C-fibers. Sodium channels play a key role in the transmission process. Indeed, topical local anesthetics, which block sodium channels and are used to treat itch, generally have a short duration of action, and importantly, ...
This study aimed to qualitatively explore the adult experience of AD.
Atopic dermatitis (AD) and bullous pemphigoid (BP) are inflammatory skin diseases in which patients often report intense pruritus and significant quality of life (QOL) impact. Although they have differences in classical presentation (eczematous eruption versus urticaria and blisters) and population characteristics (young-to middle aged persons vs. elderly), early stages of BP can appear similar to AD clinically and histologically. We wanted to explore whether there were significant similarities or differences in pruritus characteristics and QOL impact.
Introduction: The purpose of this study was to assess whether the improvements in itch seen with placebo are due to the use of minimum itch scores as an entry criterion. Methods: A systematic literature review was performed using MEDLINE to find studies that reported the effect of placebo on itch. We then characterized these studies based on whether or not itch was an entry criterion. Itch outcome in placebo arms of studies, quantified using visual analog scale (VAS), was gathered and compared to each other.
CONCLUSIONS: Methyl paraben exposure may increase the risk of itchy rash in African Americans, whereas triclosan may decrease the risk of itchy rash and eczema. The potential effect of triclosan and methyl paraben in pruritus and eczema warrants further study. PMID: 31433379 [PubMed - as supplied by publisher]