ABSTRACT
This chapter describes the objective age and gender differences in skin irritation and sensitization responses and investigates differences in sensory irritation comparing it with results from studies on self-assessed perception of sensitive skin. Studies indicate that skin characteristics such as skin thickness, barrier function, and elasticity vary with age and gender. These characteristics potentially influence skin reactivity and perception. Most parameters are entirely subjective including self-assessment of having sensitive skin or not, along with, for example, the severity, quality of discomfort and triggering factors such as physical, emotional, chemical or weather causes. Sensitization requires, opposite to irritation, an immune response and therefore immune competence to carry out a skin response to allergens—allergic dermatitis. A small study on stinging with lactic acid, which is a common objective test for sensitive skin, revealed a tendency of increased sensitivity in women, but it has no correlation when comparing discomfort in different areas of the face in the individual test persons.
