Prevalence of occupational asthma and immunologic sensitization to guar gum among employees at a carpet-manufacturing plant.
Guar gum is a high-molecular-weight agent that can cause occupational rhinitis and asthma. We surveyed the employees at a carpet-manufacturing plant in which guar gum is used to adhere the dye to the fiber; 162/177 of the employees (92%) participated in the first part of the survey that included a questionnaire and skin prick tests with common allergens and guar gum (1 mg/ml). IgE and IgG antibodies to guar gum were also measured in those subjects (133/162 or 82%) who agreed to blood tests. Thirty-seven subjects (23%) had a history suggestive of occupational asthma and 59 (36%), of occupational rhinitis. Eight subjects (5%) demonstrated immediate skin reactivity to guar gum. Eleven subjects (8.3%) had serum IgE antibodies to guar gum. All subjects, except one subject who had a history suggestive of occupational asthma (n = 37) or positive skin tests (n = 4), participated in the second part of the study. A methacholine-inhalation test was performed during a workshift or in the 3 to 4 hours after the workshift. Five subjects had a concentration of methacholine causing a 20% fall in FEV1 of less than 16 mg/ml (significant bronchial hyperresponsiveness) and positive skin reactions to guar gum. Four of these subjects underwent specific inhalation challenges. The remaining subject had a history of severe bronchospastic reaction on exposure to guar gum, and his FEV1 of 1.6 L made specific challenges impossible. Two subjects had typical isolated immediate reactions.(ABSTRACT TRUNCATED AT 250 WORDS)