Ultrastructural study of the dermis in a case of type IV Ehlers-Danlos syndrome.

Light microscopic and ultrastructural examination of the skin in a case of type IV Ehlers-Danlos syndrome (EDS) showed the presence of morphological changes involving all the dermis components. Collagen fibres were smaller, more irregular and more spaced apart than in normal dermis. Conversely, elastic, microfibrillar and amorphous components were considerably increased. Collagen fibrils presented poorly defined outlines and a loose texture, besides being markedly reduced in size. Fibroblasts were characterized by variable degrees of dilatation of RER cisternae containing flocculent material. In addition to these features, which confirm previous description of dermis structure in a case of type IV EDS (Holbrook and Byers, 1981), we have also observed thickening and delaminations of epidermal, perineurial and perivascular basement membranes and the presence of filamentous banded elements associated to nerve bundles. Moreover Langerhans' cells were found in papillary dermis, probably indicating the existence of an abnormal antigenic stimulation.