Long-term Follow-up of Atopic Dermatitis: Retrospective Analysis of Related Risk Factors and Association With Concomitant Allergic Diseases

Abstract

Ricci G, Patrizi A, Baldi E, Menna G, Tabanelli M, Masi M. J Am Acad Dermatol. 2006;55:765–771 PURPOSE OF THE STUDY. To examine the natural course of atopic dermatitis (AD), the factors influencing its persistence, and the appearance of other allergic diseases with particular focus on asthma and the presence of specific immunoglobulin E (IgE) at first observation. STUDY POPULATION. The prospective study included 252 children between 6 and 36 months of age with AD noted on first clinical visit to a pediatric or dermatology department in Bologna, Italy. METHODS. Patients were followed for 13 to 22 years. AD diagnosis was based on the criteria of Hanifin and Rajka. Allergic rhinitis and asthma were determined by physician diagnosis. AD severity was based on validated clinical score. Total IgE and specific IgE to various allergens (cow's milk, egg white, soybean, wheat, peanut, nut, codfish, tomato, grass pollens, house dust mites, cat dander, horse dander, dog dander, and Alternaria) were determined at baseline. For radioallergosorbent test (RAST) testing, ≥1 was considered positive for inhalant allergen and ≥2 was considered positive for food allergies. RESULTS. AD had completely resolved in 124 cases (60.5%). Other allergic manifestations that appeared included asthma in 70 cases (34.1%) and rhinoconjunctivitis in 118 cases (57.6%). Generally, the average age of patients who recovered from AD was higher in severe AD (6.0 ± 3.5 years) than in its moderate or mild forms (5.8 ± 4.5 and 5.5 ± 3.9 years, respectively). This phenomenon was particularly evident in children with egg sensitization, who showed a longer persistence of the condition (P < .02). The initial severity score of AD (P < .001) or egg sensitization (P < .007) was significantly related to the later development of asthma. Egg sensitization also predicted rhinitis (P < .05). A retrospective analysis of related risks factors and their association with concomitant allergic diseases showed that the egg sensitization, severity of AD, and onset of allergic rhinitis were positively related to the occurrence of asthma. CONCLUSIONS. AD severity and the course of AD are significantly related to egg sensitivity. AD severity and egg allergy are risk factors for asthma. REVIEWER COMMENTS. This article provides further evidence of the “atopic march” of AD to asthma. However, it is important to realize that a positive IgE test is simply evidence for sensitization, not confirmed clinical allergy. Also, the diagnosis of asthma and allergic rhinitis was not clearly defined. Nevertheless, patients with severe AD, egg sensitization, and allergic rhinitis are at higher risk for progressing in the atopic march to asthma and allergic rhinitis.