The role of the skin in the development of chemical respiratory hypersensitivity

Certain chemicals are known to cause occupational respiratory allergy associated with symptoms of pulmonary distress, including asthma and rhinitis. While there is no doubt that inhalation represents an important route of exposure for the development of sensitization to the inducing allergen, there is evidence that effective sensitization of the respiratory tract may result also from dermal contact with the chemical. The mechanisms relevant to the stimulation of respiratory sensitization following cutaneous exposure to chemical allergens and implications for the prevention of occupational asthma are considered here.