Objective: This study examined risk factors for eczema at age four.
Study Design: Beginning at age one, infants of atopic parents (n=636) had annual clinical evaluations and skin prick tests (SPTs) to 15 aeroallergens, and milk and egg. Parents completed validated surveys on eczema and environmental exposures. House dust samples were evaluated for allergens and endotoxin. Eczema was defined as a parental report of scratching, and redness, “raised bumps,” or dry skin/scaling for six of the last 12 months.
Results: At age four, 90 children (16%) had eczema. Not having a dog prior to age one and being dog SPT+ at ages one, two, and/or three conferred a four-fold higher risk for eczema at age four (aOR=3.9 [1.6-9.2]; p=0.002). Among dog owners, however, dog SPT+ was not associated with significantly increased risk (aOR 1.3 [0.3-6.8]; p=0.8). Among children with cats prior to age one, cat SPT+ conferred significantly increased risk for eczema (aOR= 13.3 [3.1-57.9]; p<0.001). Among non-cat owners, cat SPT+ was not associated with increased risk (aOR=1.1 [0.5-2.7]; p=0.8).
Conclusion: Dog ownership significantly reduced the risk for eczema at age four, even among dog sensitized children, while cat ownership combined with cat sensitization significantly increased the risk.