ExtractSerum IgE concentrations and the presence of allergen-specific IgE were determined in a series of 23 children with atopic dermatitis. In this group 83% had significantly elevated serum levels of IgE, 91% had coexistent respiratory allergy, 70% had radioallergosorbent test (RAST) evidence of pollen hypersensitivity, and 43% gave a history and demonstrated a RAST score consistent with milk or egg hypersensitivity. In patients with eczema a significant proportion of the elevated serum IgE appears to be antigen specific. SpeculationThe mechanisms involved in the pathogenesis of atopic dermatitis remain unknown. Elevated serum IgE and the presence of antigen specific IgE suggest a causal relationship of atopic eczema with immediate hypersensitivity. Alternatively, the disease process may ,have a marked stimulatory effect on the specific IgE response. The precise nature of this association remains to be determined.Atopic dermatitis or eczema has been defined as an allergic dermatosis which is characterized by erythema, intense itching, and vesiculation (3). Although the pathogenesis is unknown, the strong association of atopic dermatitis, asthma, hay fever, and family history of atopic disease suggests that immunologic mechanisms are frequently involved. Elevated serum IgE levels have been reported frequently in atopic dermatitis, (1,(6)(7)(8)10) and the concentration of IgE appears to be correlated with the severity of the dermatitis (6, 7). Further, Hoffman et al. (5,6) have recently demonstrated specific IgE to a wide variety of antigen in patients with eczema.The present study was undertaken to evaluate serum IgE levels in a selected group of pediatric patients seen in an allergy clinic to determine the presence or absence of allergen-specific IgE and to examine the relation of atopic dermatitis to inhalant and food allergies. SUBJECTS AND METHODS PATIENT POPULATIONThe patient population consisted of 23 children ranging in age from I to 15 years with varying degrees of symptomatic atopic dermatitis seen at the Georgetown University Allergy-lmmunology-Respiratory Disease (AIR) Clinic (Table 1). There were 10 males and 13 females in the study group. In order to examine the relationships of age and IgE, the patients were divided into four age categories: 9 were 1-4 years of age, 4 were 5-8 years of age, 6 were 9-12 years of age, and 4 were 13-15 years of age. CLASSIFICATION OF DISEASEAtopic dermatitis was classified as mild, moderate, or severe according to the extent of the eruption at the time serum samples were obtained. 'Dermatitis of limited distribution with few or no active lesions was classified as "mild." Dermatitis limited to the face, neck, or flexor surfaces of the extremities with limited erythema and vesidulation was "moderate." Extensive involvement of the trunk and extensor surfaces, severe lichenification, extensive erythema, and vesiculation or any of these in combination were classified as "severe."For the purpose of this study, allergic rhinitis or asthma was designated as present (+) or a...