LIPOID PROTEINOSIS CLINICAL, HISTOLOGIC, AND ULTRASTRUCTURAL INVESTIGATIONS

The case of a 12-year-old boy with lipoid proteinosis is reported. Phy sical examination revealed long-standing varicella-like scars and area s of hyperpigmentation on the face and upper limbs with no evidence of photosensitivity, hoarseness, small papules along the free margins of eyelids, tongue firmness with short frenulum, and widespread papular lesions of the oral cavity. Histologic and ultrastructural examination revealed the characteristic skin changes: pink, hyaline-like, strongl y periodic acid Schiff-positive material in the dermis, surrounding bl ood vessels, and sweat glands; thin (30 to 35 nm) collagen fibrils int erspersed in abundant amorphous material; blood vessels surrounded by thickened, multilayered basement membranes, in which layers of typical , homogeneous basement membrane material were alternating with electro nlucent areas filled by various amounts of thin, cross-striated fibril s, arranged perpendicularly. These findings are of great interest sinc e they show a complex relationship between type IV and type III-like c ollagen components.