Erythropoietic protoporphyria and lipoid proteinosis are compared histologically and histochemically and the early lesions described in fairly great detail. The distribution and eventual degree of hyalinization is quite different in the two conditions, being limited and perivascular in arrangement in erythropoietic protoporphyria but much more extensive and widespread in lipoid proteinosis. Histochemically, the hyaline material appears to be qualitatively identical in the two conditions.
van der Walt JJ, Heyl T. Lipoid Proteinosis and Erythropoietic ProtoporphyriaA Histological and Histochemical Study. Arch Dermatol. 1971;104(5):501-507. doi:10.1001/archderm.1971.04000230043006