ABSTRACT
Clinical conditions, such as protein contact dermatitis and immunologic contact urticaria, occur following protein contact with the skin. Yet it has long been assumed that macromolecular compounds cannot penetrate the skin barrier. In this chapter, we review the clinical, in vivo, and in vitro evidence that proteinaceous materials can penetrate skin. However, it is concluded that while penetration of intact proteins through normal skin is extremely low and normally without consequence, it is when the skin is damaged or compromised in some way that penetration of macromolecules may occur. As a result, risk assessment for contact of protein with skin must take into account potential barrier impairment and thus the possibility of both the induction and the elicitation of allergic skin reactions.
