The role of skin barrier in occupational contact dermatitis

Abstract

Skin diseases represent one of the most common work-related diseases and may have a detrimental effect on social, personal and occupational aspects of life. Contact dermatitis (CD), which comprises predominately irritant contact dermatitis (ICD) and allergic contact dermatitis (ACD), accounts for vast majority of occupational skin diseases, especially in occupations associated with frequent skin contact with irritants and contact allergens. Although ICD and ACD have similar clinical manifestation, their pathophysiology and the role of the skin barrier are different. In ICD, perturbation of the skin barrier is the primary event which sets into motion diverse metabolic processes and triggers activation of innate immunity without the involvement of adaptive immune system. In ACD, a type IV hypersensitivity reaction induced by contact allergens, the skin barrier impairment may evoke innate signalling pathways during the sensitization phase required for the activation of T-cell adaptive response. Thus, skin barrier impairment may increase the risk of ICD or ACD not only because of enhanced permeability and ingress of irritants and allergens but also by the generation of innate immune signal needed for the induction of allergic response. Hence, an efficient way to prevent CD is to avoid skin barrier damage in the workplace. This review focuses on the skin barrier, how it is affected by skin irritants and how its impairment contributes to the development of ICD and ACD.

Nickel allergy and allergic contact dermatitis: A clinical review of immunology, epidemiology, exposure, and treatment

“…The risk of elicitation on skin with a defective barrier is generally increased, because of enhanced permeability, immunomodulatory effects, or a combination of these . Allenby and Basketter showed that the elicitation threshold of a 48‐hour occluded patch test with nickel sulfate on inflamed skin was 0.0075 μg/cm 2 , which was expected to be 100 to 1000 times below the threshold on normal skin .…”

Recent Advances in the Transdermal Delivery of Protein Therapeutics with a Combinatorial System of Chemical Adjuvants and Physical Penetration Enhancements

“…The cells forming the SC are flat‐shaped corneocytes, which are surrounded by keratins that are hydrophobic, insoluble fibrous proteins. The intercellular lipid matrix within the SC is composed of ceramides, free fatty acids, and cholesterol to form a lamellar structure . The lipid matrix is connected in repeatedly stratified structure with these components, and thus performs the function of an excellent barrier to suppress the permeation of water or hydrophilic material .…”

The skin barrier: Epidermis vs environment

“…The primary function of the skin is to serve as a barrier against the environment . The epidermis of the skin prevents or minimizes the ingress of microbes, fungi, viruses, toxins, allergens and irritants, and it absorbs ultraviolet radiation and reduces damage by mechanical forces . Furthermore, the skin suppresses the loss of water, ions and metabolites .…”

“…Topics important for the basic understanding of the skin barrier include the ultrastructure and molecular composition of the skin barrier, the processes of epidermal protein phosphorylation and citrullination, the maintenance of tight junctions during keratinocyte differentiation, the synthesis of sphingomyelin in the epidermis and the evolutionary history of the genes that control the human skin barrier . The importance of the skin barrier at the crossroads of health and disease is shown by articles dealing with atopic dermatitis, occupational contact dermatitis, autoinflammation of the skin, dermatophyte infections, transglutaminase‐associated skin diseases, diabetes, acne, skin barrier modulation by tannic acid and a mouse model with atopic dermatitis‐like symptoms . Of particular interest for experimental dermatologists, advances in the proteomics of the skin barrier, corneocyte morphometry, non‐invasive techniques of skin barrier assessment and measurement of biomechanical features of skin are reported in this issue.…”