Figure 2.

Serial recordings of peak expiratory flow (PEF) for a patient with occupational asthma. Measurements made during periods at work and while off work show objective improvement of PEF while off work, particularly after 3–4 days (see lower panel). The asthma was due to inhalation of toluene diisocyanate present in a varnish that the patient used at work (exposure indicated by horizontal bars at top of graph). Arrows indicate use of reliever medication (salbutamol) for asthma symptoms. Reproduced courtesy of Dr. André Cartier and Medical Resource Communications.⁴⁷