Jerald W. Koepke

Vocal cord dysfunction: The importance of psychologic factors and provocation challenge testing

We present three case reports involving patients with vocal cord dysfunction. The onset of symptoms in one case was coincident with a generalized cutaneous reaction to penicillin with laryngeal involvement. The other cases had been misdiagnosed as food allergy and chemical sensitivity. We describe the psychologic factors in these cases in terms of the primary and secondary gain operative in the somatoform disorder of conversion reaction and emphasize the importance of belief and learned sensitivity in the induction of symptoms. The necessity of considering psychologic factors and the use of blinded, controlled, provocation challenges to evaluate subjective symptomatology is underscored. This study emphasizes the heterogenicity of clinical presentations involving vocal cord dysfunction and illustrates the value of fiberoptic-assisted examination of laryngeal function in conjunction with provocation challenge testing in establishing causal relationships for specific clinical symptoms.

Latex allergen in respirable particulate air pollution

OBJECTIVE Urban air samples contain numerous irregular respirable black particles, which may be airborne tire fragments. A major component of tires is natural latex. Proteins of natural latex can act as adjuvants and as antigens capable of eliciting immediate hypersensitivity, making their presence in particulate air pollution an important clinical issue. METHODS Particulate air pollutants were collected by volumetric sampling devices and characterized by optical microscopy, chemical solubility tests, and mass spectrometry. Extracts of rubber tire fragments were tested for elutable latex antigens by antibody inhibition assays. RESULTS Identification of latex in air samples and milled material from automobile tires was supported by mass spectrometry results and was further confirmed by physical appearance and chemical solubility studies. Competitive immunoassay confirmed the presence of extractable latex antigens from rubber tire fragments. CONCLUSIONS Latex antigens are extractable from rubber tire fragments, which are abundant in urban air samples. Given the adjuvant and sensitizing effects of latex, these airborne particles could contribute, through direct and indirect mechanisms, to the increase in both latex sensitization and asthma. The impact of these particles should be considered in the issue of morbidity and mortality rates associated with respiratory diseases and air pollution.

Sensitivity to sulfited foods among sulfite-sensitive subjects with asthma

Eight individuals with asthma who had been diagnosed as sulfite sensitive on the basis of double-blind capsule-beverage challenges were subjected to challenges with various sulfited foods, including lettuce, shrimp, dried apricots, white grape juice, dehydrated potatoes (as mashed potatoes), and mushrooms. Four of these patients failed to respond to challenges with any of the sulfited foods. The other four patients experienced a decrease in pulmonary function on double-blind challenges with sulfited lettuce. Two of three of these patients reacted to challenges with dried apricots and white grape juice; the fourth patient has not yet been challenged with these products. Only one of these four patients reacted to challenges with dehydrated potatoes and mushrooms, and, in this case, the response to double-blind challenges with dehydrated potatoes was not consistent. None of the sulfite-sensitive subjects with asthma responded to challenges with sulfited shrimp. It is concluded that sulfite-sensitive subjects with asthma will not necessarily react after ingestion of sulfited foods. The likelihood of a reaction is dependent on the nature of the food, the level of residual sulfite, the sensitivity of the patient, and perhaps on the form of residual sulfite and the mechanism of the sulfite-induced reaction.

Presence of sulfur dioxide in commonly used bronchodilator solutions

We detected a significant amount of SO2 released from commercially used bronchodilators, including isoproterenol (Isuprel; Breon Laboratories, Inc., New York, N. Y.), metaproterenol (Alupent; Boehringer Ingelheim, Ridgefield, Conn., or Metaprel; Dorsey Laboratories, Lincoln, Neb.), isoetharine (Bronkosol; Breon Laboratories, Inc., New York, N. Y.), and racemic epinephrine (Micronefrin; Bird Corp., Palm Springs, Calif.). During standard nebulization of these agents, SO2 concentration varied from 0.1 to 6.0 ppm. These levels are known to be bronchoconstrictive in asthmatic patients. We believe clinicians should be aware of this observation when sulfite-containing bronchodilators are used.

The histamine content of allergen extracts

The histamine content of 108 inhalant, food, and venom extracts from four commercial sources was measured by chemical (glass fiber-based) and immunologic (competitive RIA) methods. Histamine was present in 64 of 76 inhalant extracts (range, 0.005 to 7.4 micrograms/ml), 20 of 26 food extracts (range, 0.16 to 23 micrograms/ml), and six of six venoms, 100 micrograms/ml (range, 1.0 to 38 micrograms/ml). Histamine was removed by treatment with diamine oxidase or dialysis of an extract. Repeat assay of selected extracts after addition of known amounts of histamine in the glass fiber-based method produced additive results, and glycerin- or phenol-extract preservatives did not affect assay performance. Timed extractions of dried-pollen grains demonstrated maximal histamine content at 30 seconds, suggesting that histamine is an inherent component of at least some pollens. Histamine found in some allergen extracts could, under extreme circumstances, produce false-positive results in skin testing and in basophil histamine release assays, and could affect the result of research that uses intact pollen or allergen extracts.