Atopic dermatitis human studies

In untreated human stratum corneum there is a concentration gradient of vitamin E with the lowest levels at the surface and the highest levels in the deepest layer.50-55 This a-tocopherol gradient in the epidermis was confirmed in another study, where the stratum corneum of atopic patients had a twofold higher concentration of a-tocopherol together with a significantly lower lipid peroxide concentration than in healthy volunteers. This less pronounced oxidative stress in stratum corneum of atopic dermatitis patients may result from an increase in cutaneous antioxidant defences due to the chronic inflammation.56... 

Few human studies or clinical trials examining the potential health and/or therapeutic applications of rooibos have been reported. Dnring the early 1980s, a small (n=7) study was conducted in hnmans snffering from asthma or hay fever. Neither the ingestion of traditional rooibos nor the topical apphcation of a rooibos poultice exhibited any antihistaminic effects (75). Nearly a decade later, another human study was pubhshed that showed a positive effect an infusion of rooibos had on patients with atopic dermatitis and herpes simplex viral infection 74). A decreased itching and indnced-inflammation was reported as well as a decreased incidence of herpes simplex. As yet, no hnman studies on inunune responses have been published. 

The traditional mainstays of topical treatment for AD have been the topical corticosteroids. It is interesting to note, however, that steroids are not believed to have any effects on histamine release from human mast cells [116, 117]. A direct comparative study of the mechanism of steroids versus tacrolimus has not been performed. However, in preliminary work done by Fujisawa Laboratories in the United States utilizing sequential punch biopsies from patients with atopic dermatitis treated with either steroids or tacrolimus topically, some differences were noted in the patterns of cytokine expression between the two treatments (M. Kobayashi, personal communication, 2000). Additional studies will need to be performed before clear conclusions can be drawn. 

Rajka G (1974) Transepidermal water loss on the hands in atopic dermatitis. Arch Dermatol Forsch 251 111-115 Reed JT, Ghadially R, Elias PM (1995) Skin type but neither race nor gender, influence epidermal permeability barrier function. Arch Dermatol 131 1134-1138 Reed WB, Kierland RR, Code CF (1958) Vascular reactions in chronically inflamed skin. Ill Action of histamine, the histamine releaser 48-80 and monoethanolamine nicotinate (Nicamin). Arch Dermatol 77 263-268 Reinertson R, Wheatley V (1959) Studies on the chemical composition of human epidermal lipids. J Invest Dermatol 32 49-58 Rietschel RL (1995) Physiologic response of chronically inflamed and accommodated human skin. Curr Probl Dermatol 23 104-107... 

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