Histamine receptor-bearing mononuclear cells in atopic dermatitis

The number of mononuclear cells bearing membrane receptors for histamine was investigated in peripheral blood from children with atopic dermatitis (AD) by means of the Rosette Histamine Assay, using erythrocytes coated with histamine. Histamine Rosettes (H R) varied from 5.70 to 11.85% in healthy adults; from 3.25 to 7.75% in control children and from 2 to 6.55% in children with AD. Histidine and tryptamine inhibited HR formation slightly, whereas free histamine, histamine HI and H2 receptor antagonists and the histamine H2 receptor agonist (dimaprit) reduced HR formation much more strongly; no significant difference in inhibition of HR formation by these test agents was found between the three groups of subjects, although the reduction in HR formation by histamine was not constant in children with AD.