Clinical and inflammatory features of occupational asthma caused by persulphate salts in comparison with asthma associated with occupational rhinitis.
BACKGROUND
The relationships between asthma and rhinitis are still a crucial point in respiratory allergy and have scarcely been analysed in occupational setting. We aimed to compare the clinical and inflammatory features of subjects with occupational asthma only (OA) to subjects with OA associated to occupational rhinitis (OAR) caused by persulphate salts.


METHODS
The clinical charts of 26 subjects diagnosed in our Unit as respiratory allergy caused by ammonium persulphate (AP), confirmed by specific inhalation challenge (SIC), were reviewed. Twenty-two out of twenty-six patients underwent pre-SIC-induced sputum challenge test (IS) and 24/26 underwent nasal secretion collection and processing.


RESULTS
Twelve out of twenty-six patients received a diagnosis of OA-only and 14/26 of OAR. Duration of exposure before diagnosis, latency period between the beginning of exposure and asthma symptom onset, basal FEV(1), airway reactivity to methacholine and asthma severity did not differ in the two groups. Eosinophilic inflammation of upper and lower airways characterized both groups. Eosinophil percentage in IS tended to be higher in OAR [11.9 (5.575-13.925)%] than in OA-only [2.95 (0.225-12.5)%] (P = 0.31). Eosinophilia in nasal secretions was present both in subjects with OAR [55 (46-71)%] and in subjects with OA-only [38 (15-73.5)%], without any significant difference.


CONCLUSIONS
Our results indicate that OA because of ammonium persulphate coexists with occupational rhinitis in half of the patients. Unexpectedly, rhinitis did not seem to have an impact on the natural history of asthma. The finding of nasal inflammation in subjects with OA-only without clinical manifestations of rhinitis supports the united airway disease concept in occupational respiratory allergy as a result of persulphates.
Moscato
G
G
Allergy and Immunology Unit, Fondazione Salvatore Maugeri, Institute of Research and Care, Scientific Institute of Pavia, Via Maugeri 10, Pavia, Italy. gianna.moscato@fsm.it
Pala
G
G
Perfetti
L
L
Frascaroli
M
M
Pignatti
P
P
D000328:Adult; D000645:Ammonium Sulfate / Q000633:toxicity*; D001249:Asthma / Q000139:chemically induced / Q000209:etiology* / Q000473:pathology; D004802:Eosinophilia / Q000209:etiology; D005260:Female; D006801:Humans; D007249:Inflammation / Q000209:etiology*; D008297:Male; D016210:Methacholine Chloride / Q000494:pharmacology; D009784:Occupational Diseases / Q000139:chemically induced / Q000209:etiology* / Q000473:pathology; D012189:Retrospective Studies; D012220:Rhinitis / Q000150:complications* / Q000209:etiology / Q000473:pathology; D055815:Young Adult
D016210:Methacholine Chloride; C031276:ammonium peroxydisulfate; D000645:Ammonium Sulfate