Emphysema due to smoke from a herbal asthma remedy

A 79-year-old man was referred to us for possible lung volume reduction surgery. He was a lifelong non-smoker but had had mild asthma since the age of 10. He had never required hospitalization nor used inhaled bronchodilators until a few years previously when he had been diagnosed with COPD. His MRC dyspnoea score was 4. Spirometry revealed an FEV1 of 0.88L (25% predicted), an FVC of 4.48 L (94%) predicted with an FEV1/VC ratio of 24% and no additional improvement with bronchodilators. Lung volumes were increased; total lung capacity was 117% predicted and residual volume 156% predicted. Gas transfer values were reduced; TLcoc of 35% predicted, Kcoc of 63% predicted. Arterial PaCO2 was 4.0 kPa and PaO2 7.2 kPa. CT thorax showed diffuse emphysema throughout both lungs, with bullous changes at both bases (Figure 1). He reported no occupational exposure to any pulmonary irritants, nor any exposure to animals or birds. Further enquiry revealed that from the age of 12 years, for about 50 years, he had controlled his asthma by inhaling smoke from a preparation called Potter’s ‘Asthma Remedy’, the presumptive cause of his emphysema.