Stratum Corneum Ceramides and Free Amino Acids in the Lesion of Scaly Hand Eczema

Lee, Mi Ae; Hahm, Jeong Hee

Abstract

BACKGROUND: Lipids of horny layer forming multiple lamellar structure in the intercellular space acts as a skin barrier having a primary protective function and keeps softness and flexibility of the skin by absorbing and maintaining moistures. Among the intercellular lipids, ceramides mainly contribute to this important role. In xerotic eczema, atopic dermatitis, psoriasis, ichthyosis, and experimentally induced scaly lesion showing dryness and scales, the amount of ceramides is decreased or distribution of ceramide is changed. In addition to lipids, free amino acids, a component of NMFs, serve as a water retainer and are decreased in ichthyosis or experimentally induced scaly lesion. Hand eczema has dry and scaly lesion showing impaired skin barrier and low water content. So, changes of ceramides or free amino acids can be considered in the lesion of hand eczema.
OBJECTIVE
The purpose of this study was to confirm the relationship between the development of hand eczema and changes of ceramides or free amino acids. METHOD: The lipids and free amino acids in scales from lesion of hand eczema were analyzed by using high performance thin layer chromatography and amino acid analyzer.
RESULTS
Amounts of total lipids extracted were 0.63+/-0.33 microgram/cm2 in hand eczema and 0.44+/-0.26 microgram/cm2 in control. There was no difference between the two groups. Cholesterol sulfate, glucosyl ceramide, cholesterol, triglyceride, sterol ester, and n-alkane showed no difference between hand eczema and control. But ceramides were significantly decreased in hand eczema(11.0+/-5.5%) compared with control(21.4+/-8.0%)(p<0.05). Especially, ceramide type IV was significantly decreased in hand eczema (6.6+/-5.3%) compared with control(15.6+/-6.2%)(p<0.05) but ceramide type III in hand eczema did not differ from control. Amounts of total free amino acids in 10mg of scale were 10.4+/-3.1nmol in hand eczema and 9.5+/-3.0nmol in control. There was no significant difference between the two groups.
CONCLUSION
Dry skin and scales in hand eczema are related to the decrease of total amount of ceramides and ceramide type IV than amino acids in horny layer. To clarify the exact pathogenesis of hand eczema, further investigations on all types of ceramides and their defect in the process on biosynthesis of ceramides will be necessary.