Allergies and agricultural exposure as risk factors for multiple myeloma.

In a case-control study of 84 multiple myeloma patients and 168 age- and sex-matched controls with tumours at other sites, reported prior allergies were associated with an elevated risk of myeloma (RR = 3.1, P less than 0.001). In addition, more myeloma patients than controls reported prior myxoedema (RR = 5.0, P = 0.04). History of agricultural work was associated with an elevated risk of myeloma (RR = 2.2, P = 0.01), although no detailed information was available on the type of farming in which the subjects were engaged. More detailed studies are required to confirm and further delineate these findings.