In humans, skin barrier dysfunction is thought to be responsible for enhanced penetration of allergens. Similar to conditions seen in humans, canine atopic dermatitis (CAD) is characterized by derangement of corneocytes and disorganization of intercellular lipids in the stratum corenum (SC) with decreased ceramide levels. This study was designed to evaluate the effects of a moisturizer containing ceramide on dogs with CAD. Dogs (n = 20, 3~8 years old) with mild to moderate clinical signs were recruited and applied a moisturizer containing ceramide for 4 weeks. Transepidermal water loss (TEWL), skin hydration, pruritus index for canine atopic dermatitis (PICAD) scores, and canine atopic dermatitis extent and severity index (CADESI) scores of all dogs were evaluated. Skin samples from five dogs were also examined with transmission electron microscopy (TEM) using ruthenium tetroxide. TEWL, PICAD, and CADESI values decreased (p < 0.05) and skin hydration increased dramatically over time (p < 0.05). Electron micrographs showed that the skin barrier of all five dogs was partially restored (p < 0.05). In conclusion, these results demonstrated that moisturizer containing ceramide was effective for treating skin barrier dysfunction and CAD symptoms.
Animals ; Ceramides/*therapeutic use ; Cholesterol/*therapeutic use ; Dermatitis, Atopic/complications/drug therapy/physiopathology/*veterinary ; Dog Diseases/*drug therapy/etiology/physiopathology ; Dogs ; Emollients/*therapeutic use ; Epidermis/drug effects/physiopathology/ultrastructure ; Fatty Acids, Nonesterified/*therapeutic use ; Female ; Male ; Microscopy, Electron, Transmission/veterinary ; Pruritus/drug therapy/etiology/physiopathology/veterinary ; Republic of Korea ; Ruthenium Compounds/chemistry ; Water Loss, Insensible/drug effects

Increased transepidermal water loss (TEWL) and downregulated antimicrobial peptides (AMPs) are observed in patients with atopic dermatitis (AD). Tacrolimus and ceramide-dominant emollients are effective in the treatment of AD by preventing the production of inflammatory cytokines and by correcting skin barrier dysfunctions, respectively. Present study was designed to investigate the relationship between antimicrobial and barrier factors by measuring the changes of AMPs and TEWL after topical application of tacrolimus and ceramide-dominant emollient in the patients with AD. A total of three patients with AD were treated with tacrolimus in one lesion and ceramide-dominant emollient in another lesion for 4 weeks. RT-PCR and western blotting revealed that the mRNA and protein expression levels of hBD-2 and LL-37 were increased on the both study sites. Immunohistochemical analysis showed significant increase of AMPs and IL-1alpha, while, IL-4 was decreased on the both study sites. The mean changes of TEWL and AMPs showed no statistical difference between both sites. Tacrolimus and ceramide-dominant emollient influence on both TEWL and AMPs expression in patients with AD, namely they have similar effects on both of the two. This study shows that restoration of permeability barrier function is accompanied by the concomitant improvement of antimicrobial defense in patients with AD.
Administration, Topical ; Adolescent ; Antimicrobial Cationic Peptides/*metabolism ; Ceramides/*administration & dosage ; Dermatitis, Atopic/*drug therapy/*metabolism ; Emollients/administration & dosage ; Female ; Humans ; Immunosuppressive Agents/administration & dosage ; Male ; Skin Absorption/*drug effects ; Tacrolimus/*administration & dosage ; Treatment Outcome ; Water Loss, Insensible/*drug effects ; Young Adult