Diffuse panbronchiolitis is a severe, progressive form of bronchiolitis, an inflammatory condition principally affecting the bronchioles (small air passages in the lungs).
It was first described in the 1960s in Japan, where it affects around 1 in 10,000 people. It causes wheezing and difficulties in breathing. If left untreated it's usually fatal. Treatment with modern antibiotics can greatly improve the survival rate (90%) - but currently there is no permanent 'cure'.
The cause of the disease is unknown. It's suspected to be an immune system malfunction with links to faulty genes. There may also be links with cystic fibrosis.
Technical information European Respiratory Journal, 28: 862-871;