Role and application of provocation in the diagnosis of occupational latex allergy

Abstract

INTRODUCTION Allergic sensitivity to the plant protein constituents of natural rubber latex has become a major occupational hazard for health care workers and for certain patients with repetitive latex exposures.1,2 Epidemiologic studies from Europe indicate that between 2.2% and 10.7% of health care workers and between 1% and 2% of laboratory personnel are latex allergic.3–5 More recently, Brown et al studied a group of anesthesiologists and found the prevalence of latex allergy with clinical symptoms to be 2.4% and the prevalence of asymptomatic latex sensitization to be 10.1%.6 The prevalence of latex sensitization in children with spina bifida approaches 45%, possibly due to prolonged or repeated latex allergen exposure due to multiple surgical procedures and/or chronic indwelling catheters.7–9 Contact urticaria is the most common manifestation of latex allergy. The clinical sequelae of latex allergy also include other rashes, rhinoconjunctivitis, asthma, and systemic anaphylaxis.2 These allergic reactions are elicited in sensitized individuals by exposure to a group of allergenic latex proteins. Some allergen attaches to cornstarch particles and becomes airborne when powdered latex gloves are used.10 Latex proteins can also be absorbed through repeated contact with the skin (especially after abrasion) or mucosal surfaces. The diagnosis of latex allergy depends primarily on a clinical history in which latex exposure is associated with clinical allergy symptoms. Confirmatory skin tests and serologic tests that have been developed to measure specific anti-latex IgE often have reduced sensitivity and specificity.11–13 When the clinical history and anti-latex IgE tests are discordant, natural provocational procedures are useful to adjudicate the patients’ true latex sensitivity status.