Exogenous origin of n-alkanes in pathologic scale
Williams, M.L.; Vogel, J.S.; Ghadially, R.; Brown, B.E.; Elias, P.M.
Archives of Dermatology 128(8): 1065-1071
1992
ISSN/ISBN: 0003-987X PMID: 1497360 Document Number: 397266
Background: Although n-alkanes accumulate in some disorders of cornification, recent studies using radioactive carbon 14 content by accelerator mass spectrometry point to an exogenous origin for alkanes in normal stratum corneum, and their derivation in congenital ichthyosiform erythroderma remains-controversial. Design and results: Using 14C content to measure sample age, the n-alkane fractions from two patients with congenital ichthyosiform erythroderma contained no detectable contemporary materials. By electron microscopy, alkane-enriched emollients (petrolatum [Vaseline]) permeated to all levels of stratum corneum of hairless mice, expanding the intracellular domains and distorting membrane bilayers. Similar ultrastructural changes were also observed in the stratum corneum of patients with congenital ichthyosiform erythroderma. When alkanes were excluded, no differences in lipid content were evident between two forms of autosomal recessive ichthyosis. Conclusions: These data demonstrate that scale n-alkanes in disorders of cornification derived from environmental sources and indicate the pervasiveness of petroleum-based emollients in skin. Therefore, epidermal lipid analyses must be interpreted with caution. However, these studies do not rule out an important therapeutic and/or pathogenic role for exogenous n-alkanes in skin.