Immediate and delayed hypersensitivity reactions to birch pollen in patients with atopic dermatitis

We investigated immediate and delayed hypersensitivity to birch pollen in 10 patients with atopic dermatitis (AD) who had experienced a worsening of their eczema during the birch pollen season. The patients were prick- and patch-tested and antigen-induced basophil histamine release and lymphocyte proliferation were measured. 9/10 birch pollen-allergic patients proved positive in the histamine release test and the results correlated with specific IgE levels measured by RAST. Birch pollen antigen induced lymphocyte proliferation in 6/10 patients, but a positive patch test result was obtained in only one case. Both peripheral blood monocytes and purified epidermal Langerhans' cells were able to present birch pollen antigen to T cells, although Langerhans' s cells seemed to function less efficiently in this respect.