Patients with a history of contact allergies may be less likely to develop nonmelanoma skin cancer, brain cancer, and breast cancer, a study has shown. In research published online July 11 in BMJ Open (doi:10.1136/bmjopen-2011-000084), investigators conversely found diagnoses of bladder cancer more likely in people with a history of contact allergies. Any protective effects could possibly be explained by the stimulation of natural killer T (NKT) cells through contact allergic reactions, the observational...