[Occupational asthma and interstitial cobalt-induced changes in a dental technician: a case report]

It is a case report on a 55-year-old non-smoking female, dental technician, with a 36-year history of cobalt exposure. The patient suffered from dyspnea, coughing and decrease in physical load tolerance about 20 years after the first occupational contact with cobalt-containing metal dentures. Skin tests performed with a battery of common allergens (metals: nickel, chrome, cobalt; acrylates; disinfectants; and natural rubber latex) were negative. In the patient, interstitial radiological changes, respiratory insufficiency and decrease in diffusion capacity were observed. While performing a provocation test with 0.05% cobaltous chloride, the patient developed dyspnea with concomitant decrease in 1 second forced expiratory volume (FEV1) and peak respiratory flow (PEF) from the beginning of the 3rd hour after provocation and maximum intensity at the 8th hour. These symptoms persisted until the 24th hour. The authors conclude that occupational exposure of the dental technician to cobalt dust derived from metal dentures may cause chronic airway disease with interstitial inflammation, fibrosis and occupational asthma.