Mitosis of mast cells in skin lesions of atopic dermatitis.

Mitoses of mast cells with cytoplasmic granules were observed in 6 out of 55 skin lesions of atopic dermatitis. It is thus likely that the local proliferation process of mast cells contributes to the increased number of mast cells in skin lesions of atopic dermatitis. Mitotic mast cells with cytoplasmic granules were also observed in 2 out of 8 dinitrochlorobenzene contact dermatitis lesions provoked in patients with atopic dermatitis. It is suggested that some mast cells in skin lesions of atopic dermatitis might be involved in the pathogenesis of type IV eczematous skin lesions of the disease.