Cutaneous basophil hypersensitivity in atopic dermatitis.

The infiltration by basophils into delayed hypersensitivity skin test sites was examined in patients with atopic dermatitis, contact dermatitis and in normal healthy persons. Atopic dermatitis patients, with large amounts of IgE, injected intradermally with staphylococcal antigens showed reactions that were more transient and erythematous than those of normal persons. On histological examination there were numerous, degranulating basophils among the perivascular mononuclear cells. Normal persons, with small amounts of IgE showed typical mononuclear cell infiltration and few basophils. Patients with contact dermatitis, one with much IgE, responded to patch tests to potassium dichromate or to nickel sulphate by delayed type reactions, but on histology, two of the four patients showed a significant infiltration by basophils. It is considered that the erythematous response to the antigen in atopic dermatitis patients is related to the basophil infiltration.