Changing Patterns of Sensitivity to Common Contact Allergens

Abstract

The most important factors influencing the incidence of allergic sensitivity to contact allergens are discussed. A comparison is made in selected patient populations between the incidence of allergic contact sensitivity ("index of sensitivity") to nickel sulfate, potassium dichromate, mercury bichloride, paraphenylenediamine, and formaldehyde in 1937 and in 1961-1962. No significant changes have taken place in the index of sensitivity to nickel sulfate and potassium dichromate. However, the index of sensitivity to the other substances has increased as follows: mercury bichloride 180%, paraphenylenediamine 140%, and formaldehyde 290%. These changes are attributable to increased opportunities for exposure to these substances. Most of the test reactions are considered to be indicative of latent sensitivity ("immunologic imprints") rather than the result of allergic sensitization associated with clinical disease due to these substances.