People who suffer from certain skin allergies are more likely to develop blood-related cancers when they get older. Swedish researchers report these findings in a study in the most recent issue of BMC Public Health. The research shows people who experience hives are more likely to develop leukemia. Those who have eczema in childhood are about two-times more likely to develop non-Hodgkins lymphoma. Investigators believe the skin allergies might lead to cancer because they stimulate the immune system to increase the number of white blood cells, which in turn might foster cancer-causing mutations within the white blood cell population. This finding runs counter to previous medical wisdom, which holds allergic diseases might actually protect against cancer because they stimulate the immune system to work harder. Findings from our study do not support the immune surveillance hypothesis, write the authors, which stipulates that allergic conditions protect against malignancies by enhancing the ability of the immune system to detect and eliminate malignant cells. The researchers found no link between later cancers and other allergic conditions, such as hay fever. However, results did trend toward a higher leukemia risk among those with asthma. The authors urge people to consider these findings in relation to the overall risk for blood cancers, which is low. Non-Hodgkins lymphoma, for example, only strikes about 0.03 percent of the population in the United States. The study was conducted among more than 16,500 twins in Sweden who were followed for more than 30 years.
SOURCE: BMC Public Health, published online Nov. 4, 2004
