Calcium ions (Ca2+) and atopic dermatitis (AD).
Department of Medical and Morphological Science, University of Insubria, Varese, Italy
Calcium (Ca2+) is a chemical element, the most abundant metal in the human body, which plays a vital role in the physiological and biochemical processes of the bone, muscle and neurons. Atopic dermatitis (AD) is a chronic, recurrent, eczematous and pruritic disease presenting with immune dysfunction linked to Th22 and Th17 cells. AD can manifest by autoreactive IgE participating in AD and some inflammatory cytokines may be involved in the sensation of itching. The epidermal barrier protects humans from external physical and chemical insults, as well as from biological ones such as bacteria, viruses, parasites, and fungi. Keratinocytes are important for the formation of the epidermal barrier. Extracellular calcium activates keratinocytes that are malfunctioning in skin diseases, as for example AD. Ca2+ is very important for the regulation of many skin functions, including homestasis, and diferentiation of immune cells. For example, it has been reported that Ca2+ accumulates in the endoplasmic reticulum and is crucial for the differentiation of keratinocytes that protect the skin from infections. Therefore, calcium homeostasis and vitamin D are recognized as immunomodulators. However, the association of Ca2+, vitamin D and AD is not yet clear and represents an interesting object of study.