Occupational asthma from natural rubber latex. Specific inhalation challenge test and evolution.
BACKGROUND
Natural rubber latex (NRL) is the most frequent cause of occupational respiratory problems in hospital workers.


OBJECTIVE
To describe the diagnostic methodology, including the specific inhalation challenge (SIC), used on patients diagnosed as having occupational asthma due to NRL in our Allergy Department during a 6-year period from 1989 to 1995.


METHODS
In 19 patients diagnosed as having occupational asthma due to NRL, clinical severity was assessed with a combined score for symptoms and medication use. Skin prick tests with aeroallergens, latex, papain, kiwi and chestnut, total IgE, serum-specific latex IgE, respiratory function study, methacholine test, specific conjunctival test, and SIC test with latex were done.


RESULTS
All but three patients worked in hospitals. All presented urticaria and rhinoconjunctivitis, and six also suffered anaphylaxis, usually preceded by asthma. Clinical fruit allergy was present in eight patients. The latency period was variable (0.25-27 years). The intensity of symptoms was low to moderate. Specific IgE, skin prick, and conjunctival tests to latex were positive in all cases. SICs were done in 12 patients. All of them presented isolated immediate reactions. No adverse reactions were observed. Duration of follow-up ranged from 1 to 7 years. Twenty-six percent of the patients kept their job, 26% changed jobs but remained in health care, and 48% switched to jobs unrelated to health care. Only 16% were free of symptoms without treatment, while 32% needed bronchodilators and 52% needed inhaled steroids. The specific bronchial challenge test was safe, but it did not predict the course of the illness. Duration of exposure and intensity of symptoms did correlate with prognosis, however.


CONCLUSIONS
NRL acts as a common aerollergen. Minor symptoms often precede occupational asthma. The SIC test was safe in the hands of trained technicians. Occupational asthma due to NRL seems to have a poor prognosis.
Acero
S
S
Sección Alergología, Hospital Virgen del Camino, Pamplona, Spain.
Alvarez
M J
MJ
García
B E
BE
Echechipía
S
S
Olaguibel
J M
JM
Tabar
A I
AI
D000328:Adult; D001249:Asthma / Q000175:diagnosis* / Q000209:etiology; D001985:Bronchial Provocation Tests; D015331:Cohort Studies; D005260:Female; D005932:Gloves, Surgical / Q000009:adverse effects; D006801:Humans; D020315:Latex Hypersensitivity / Q000150:complications / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000175:diagnosis* / Q000209:etiology; D010328:Patch Tests; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D012408:Rubber / Q000009:adverse effects; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
D012408:Rubber