Occupational asthma due to chromium and nickel salts

Background: Exposure to chromium and nickel salts is a poorly characterized cause of occupational asthma. Methods: We describe four patients with work-related asthma due to metallic salts. Skin–prick tests to potassium dichromate and nickel sulfate were performed. The patients underwent methacholine inhalation tests and specific inhalation challenges (SIC) with both chromium and nickel salts. Results: Two patients showed positive skin–prick tests to potassium dichromate and nickel sulfate. All patients had bronchial hyperresponsiveness to methacholine, which increased 24 h after SIC with metallic salts. SIC with potassium dichromate elicited late asthmatic reactions (LAR) in two workers, one subject had an early asthmatic reaction (EAR), and another subject showed a dual asthmatic reaction (DAR). SIC with nickel sulfate induced a DAR in one subject and a late asthmatic reaction in another. Conclusions: Chromium and nickel salts can give rise to occupational asthma in exposed workers. The underlying mechanism may be IgE-mediated in some cases.