Occupational asthma in a hairdressing salon.
Occupational asthma among hairdressers has been recognised for some years and cases of work related asthma due to hair bleaches containing persulphates and hair dyes have been reported. The extent of the disease among hairdressers remains unknown. An investigation was carried out on an entire hairdressing salon, which specialised in hair bleaching and colouring and which employed 23 staff. On the basis of history and specific and non-specific bronchial provocation testing, four out of 23 staff were found to have occupational asthma due to the persulphate salts contained in hair bleaches. Only one of these had a positive skinprick test response to persulphate salts. Tests for non-specific bronchial reactivity to histamine in this work force were more sensitive for the diagnosis of asthma than simple lung function tests or recordings of peak flow rates performed four times daily for three weeks. The response to these agents was studied in greater detail by specific bronchial provocation tests in 14 members of the salon as well as one hairdresser from elsewhere with occupational asthma, three individuals with non-occupational asthma, and four normal subjects. Only those with a history of work related asthma and bronchial hyperreactivity responded positively, confirming that the response to bleach powders was specific. Studies of pulmonary mechanics after challenge showed that the response arose from changes in airway calibre not lung volumes. Measurement of neutrophil chemotactic activity after challenge showed significant rises in those affected, suggesting that mast cells may play a part in the pathogenesis of occupational asthma due to persulphates.