[Ultrastructural image of the Langerhans cells in the skin of patients with allergic contact dermatitis].

The alterations in the ultrastructural feature of Langerhans cells in patients with allergic contact eczema were characterized by significant increase in number of Birbeck granules accompanied by the increase in volume of smooth- and rough-surfaced endoplasmic reticulum. These changes may be regarded as a morphological expression of the increase of the synthetic and secretory activity of the Langerhans cells. In the epidermis the Langerhans cells associated with immediately adjacent precursor cells (the so called indeterminate cells), lymphoid cells and keratinocytes form the morphologically visible and probably functional units.