Abstract
Atopic dermatitis is a most common chronic inflammatory skin diseases, and it is often characterized by itch, inflammation, and disruption of skin barriers. Itch associated with atopic dermatitis severely impacts the quality of life of individuals, families, and caregivers, and the incidence of itch is increasing. Here, we focused on the interplay between histamine, food, and itch mechanisms in atopic dermatitis. Histamine, a biogenic amine, plays a significant role in the pathogenesis of atopic dermatitis and related itch, and histamine levels are found elevated in atopic dermatitis individuals. A histamine-rich diet, such as ingesting foods rich in histamine and foods that trigger the cellular release of histamine, exacerbates atopic dermatitis symptoms, and the elimination of a histamine-rich diet attenuates the pathology. Further, we discussed the role of histamine receptors, specifically H1 and H4, in itch and inflammation associated with atopic dermatitis. Drugs such as antihistamines are effective in some cases, but fail to alleviate itch in atopic dermatitis, suggesting non-histaminergic itch pathways. In addition, we discussed enzymes such as diamine oxidase and histamine N-Methyltransferase, which are involved in the metabolism of histamine and, by inhibiting the activity of these enzymes leading to the accumulation of histamine, which, in turn, is responsible for atopic dermatitis and associated itch. This review provides intricate interactions between itch, diet, and histamine in atopic dermatitis and provide essential mechanistic insights and further in the development of future therapeutics.