Pathogenesis of abnormal keratinization in ichthyosiform cetrimide dermatitis: an ultrastructural study.

We have previously reported 18 cases of an ichthyosiform contact dermatitis caused by antiseptic solutions containing 3% cetrimide and 0.3% chlorhexidine. The reaction was traced to cetrimide, a mixture of quaternary ammonium compounds that are widely used as disinfectants and detergents. Quaternary ammonium compounds are known irritants. To elucidate the pathogenesis of the abnormal keratinization caused by cetrimide, electron microscopy was performed on biopsied lesions from five patients and on specimens from rabbits in which a mild reaction had been induced by closed patch with Savlon, cetrimide, and chlorhexidine. The patients' samples revealed hyperkeratosis with striking vesiculation of lamellar bodies in the granular cells and upper spinous cells, premature secretion of lamellar bodies, and abundant remnants of lamellar bodies and retention of desmosomes between the corneocytes. Similar lamellar bodies changes were induced in rabbit skin after 48 hours of closed patch with Savlon 1:30 and cetrimide 0.1%, but not with chlorhexidine 3%-further indication that cetrimide was the cause of the dermatitis. We conclude that the abnormal keratinization can be attributed, at least in part, to dysfunction of lamellar bodies resulting from the direct effects of cetrimide on the lipids and enzymes of lamellar bodies. Vesiculation with dysfunction of lamellar bodies may be an important pathogenetic mechanism in irritant dermatitis caused by quaternary ammonium compounds.