Does a family history of allergy predict immediate skin test reactivity?

The value of a family history of allergy in predicting atopy was assessed in men employed in lumber mills, grain handling and railway industries in British Columbia. Detailed family and personal histories of allergy were available for 1434 men, 1426 of whom underwent prick skin testing with two common environmental allergens and one control solution. Those with a family history of allergy had 2.06 times the odds of immediate skin test reactivity as those without a family history and 1.65 (p less than 0.01) times the odds after adjustment for personal history and age. The odds of skin test reactivity in workers with a personal history of allergy were 4.76 times those of workers without such a history and 4.34 after adjustment for family history and age. Almost half (47%) of the workers with both a family and a personal history of allergy had positive results of skin testing, compared with only 10% of the workers without either history. It was therefore concluded that a family history of allergy is an independent predictor of atopy.