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Report of occupational asthma due to phytase and β-glucanase
  1. T M O'Connora,
  2. J F Bourkeb,
  3. M Jonesc,
  4. N Brennana
  1. aDepartment of Respiratory Medicine, Mercy Hospital, Cork, Ireland, bDepartment of Dermatology, South Infirmiary Victoria Hospital, Cork, Ireland, cDepartment of Occupational and Environmental Medicine, Imperial College, London, UK
  1. Dr T M O' Connor, Department of Respiratory Medicine, Cork University Hospital, Wilton, Cork, Republic of Irelandterryoconnor{at}


OBJECTIVES Occupational asthma is the principal cause of respiratory disease in the workplace. The enzymes phytase and β-glucanase are used in the agricultural industry to optimise the nutritional value of animal feeds. A relation between these enzymes and occupational asthma in a 43 year old man was suspected.

METHODS Inhalation challenge tests were performed with the enzymes phytase, β-glucanase, and amylase. Skin prick tests were performed with the enzymes diluted to a concentration of 1 mg/ml and 5 mg/ml. Specific IgE to phytase and β-glucanase were measured with a radioallergosorbent test.

RESULTS Baseline spirometry values were normal. A histamine challenge test showed bronchial hyperreactivity. Exposure to phytase and β-glucanase led to significant reductions in forced vital capacity and forced expired volume in 1 second. No significant differences were noted after exposure to amylase. Skin tests showed a positive reaction to β-glucanase (5 mm) at a concentration of 1 mg/ml and positive reactions to β-glucanase (7 mm) and phytase (5 mm) at a concentration of 5 mg/ml. Similarly specific IgE was present against both phytase and β-glucanase, at 2.5% and 9.3% binding respectively (2% binding is considered positive).

CONCLUSIONS This is the first description of occupational asthma due to the enzymes phytase and β-glucanase. Their addition to the ever increasing list of substances associated with occupational asthma will have notable implications for those exposed to these enzymes.

  • occupational asthma
  • phytase
  • β-glucanase

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