The serum
IgE level and the population of Fc epsilon R2+ lymphocytes in peripheral blood of 62 patients with
atopic dermatitis (AD) were studied.
IgE was increased in the majority of the patients with personal or family history of
asthma and/or
allergic rhinitis (combined AD). On the contrary, only 63.2% of the patients who have solely AD (pure AD) showed less elevation of
IgE. There was no correlation between
IgE and the severity of
dermatitis in pure AD and
rhinitis combined AD. However,
asthma combined AD showed a significant positive correlation between
IgE and the severity of
dermatitis. In AD, the population of Fc epsilon R2+ lymphocytes significantly correlated with
IgE, suggesting that Fc epsilon R2+ lymphocytes may play a role in the enhanced synthesis of
IgE. However, the increase of Fc epsilon R2+ lymphocytes was found only in combined AD, but not in pure AD. These results suggest that elevated
IgE and Fc epsilon R2+ lymphocytes reflect combined respiratory atopy rather than AD itself, although there remains the possibility that
IgE may influence the formation or exacerbation of
dermatitis in
asthma combined AD. As far as the participation of
IgE is concerned, pure AD and
asthma combined AD could be different groups and should be investigated separately.