In a study published in the July 11 issue of BMJ Open researchers claim to have found a direct association between contact allergies and non-melanoma skin and breast cancer as well as positive associations with bladder cancer.
Research conducted at the Copenhagen University Hosptital Gentofte in Denmark found that contact allergy (a type IV allergy) and cancer levels increased between both men and women.
According to the researchers:
"The inverse associations support the immunosurveillance hypothesis (i.e., individuals with an allergy are less likely to get cancer due to a triggered immune system), while the positive association with bladder cancer could be due to accumulations of chemical metabolites in the bladder."To gather their findings the researchers linked to hospital registers of patients with dermatitis who were tested for contact allergy and logistic regression analysis was then used to discover their findings in groups with 40 or more patients.
It should be noted that the research study is not conclusive but rather used as a stepping stone towards more research based on the research teams hypothesis.