Wolkerstorfer A, Wahn U, Kjellman NIM, Diepgen TL, De Longueville M, Oranje AP. Clin Exp Allergy. 2002;32:70–73
Purpose of the Study.
To investigate the natural course of sensitization to egg and cow’s milk and its relationship to severity of atopic dermatitis (AD).
Study subjects were 397 European children 12 to 24 months old with AD who had been randomized to the placebo group as part of the ETAC study, which is a study examining the effectiveness of treating at-risk atopic children with cetirizine (vs placebo) in preventing the development of asthma.
The children were examined for objective assessment of AD severity using the SCORing Atopic Dermatitis (SCORAD) system and they underwent testing for food sensitivity to egg and cow’s milk using specific immunoglobulin E (IgE) by radioallergosorbent test (RAST). SCORAD of <15 = mild AD, 15 to 40 = moderate AD, and >40 = severe AD. They had assessments at baseline, 3, 12, and 18 months. A total of 382 subjects completed the study.
At baseline most of the children had mild to moderate AD; 50% were sensitive to egg and 36% were sensitive to milk. Most of the children who were sensitized to milk were also sensitized to egg (88%), but 33% of the children were only sensitized to egg. The SCORAD scores were higher at baseline for children with both milk and egg sensitivity (mean ± standard deviation [SD]): children with normal specific IgE (SCORAD = 17 ± 10), children with milk-specific IgE only (SCORAD = 18 ± 10), children with egg-specific IgE only (SCORAD = 20.5 ± 12) and children with both egg and milk sensitivity (SCORAD = 23.1 ± 12). Sensitization to milk and egg was more common in children with more severe AD at all time points of the study. The RAST level, particularly for egg, was strongly related to the severity of AD. Sensitization to egg or milk at the beginning of the study was associated with a higher rate of persistence of AD at 18 months. In children with negative specific IgE at baseline, only 57% had active AD at the end of the study, versus 84% of the egg-sensitized and 67% of the milk-sensitized subjects who had persistent AD at the 18-month time point. AD improved on average throughout the 18-month study, however, children in whom sensitization to milk increased had significantly less improvement and egg-sensitized children had deterioration of their AD.
The authors found an association between severity of AD and sensitization to egg or to milk. They further conclude that sensitization to milk, and, in particular, to egg is a negative predictor for severity of AD and persistence of AD.
This study demonstrated an association between the severity and persistence of AD with milk and/or egg sensitization. Other studies have shown that food-allergic children will have improvement in their AD if placed on an elimination diet. The authors acknowledge that they did not address other contributors to AD severity such as environmental trigger, infections, skin care regimens and irritants. They also note that they did not track the specific diets of these children, but speculate that the children with food sensitivity and more severe AD would be more likely to remove offending foods from their diet than the other group. This study further emphasizes the importance of evaluating children with AD for food sensitivity, particularly in patients with moderate to severe AD.