“…29], The aetiology of this distressing condition is ob scure, but genetic, environmental and psy chological factors, together with pharmaco logical and immunological disturbances, both of the humoral and the cellular im mune response, are implicated in its patho genesis [18,29]. During recent years, the at tention was focused on the hyperproduction of IgE [5,28,[30][31][32][33] and on the deficiency in a small subpopulation of T cells, notably suppressor cells, with immunoregulatory functions [4,9,21,26], Evidence has also been produced that the IgG4 subclass of IgG antibodies, previously described as 'short term anaphylactic IgG antibodies' [16,17] plays a role in the production of allergic asthma or in eliciting adverse reactions to foodstuffs [1,3,6,13]. However, here are on ly few reports concerning the behaviour of IgG4 in AD [7,8,22], While these studies were carried out on adults or a mixture of adults and children, or children with con comitant respiratory diseases, we have con fined this study to children only and evalu ated the relationships between the serum IgE and IgG4 levels and the severity of the dis ease and the coexistence of respiratory aller gy (RA), taking into consideration the agedependent distribution of both, the IgE and IgG4 values [12,14,23,27],…”