Comparison of barrier function and lipids in psoriasis and essential fatty acid-deficient rats

Abstract

Summary Elevated rates of transepidermal water loss (TEWL) in plaques of human psoriasis and in the skin of essential fatty acid (EFA)‐deficient rats were compared. Cutaneous application of sunflower seed oil to EFA‐deficient rats lowered the rate of TEWL to normal, healed the characteristic scaly skin of this condition and increased the incorporation of linoleic acid of the sunflower seed oil into epidermal phospholipid. Application of sunflower seed oil to psoriatic skin did not lower the TEWL, nor produce clinical improvement, but the linoleic acid of epidermal phospholipid was increased. Local application of a steroid ointment, clobetasol propionate (Dermovate) reduced the elevated TEWL in psoriasis and produced clinical improvement, but had no effect upon skin or plasma lipids. Application of this steroid to EFA‐deficient rat skin cleared the skin scaliness but did not restore barrier function or change the composition of the skin lipids. It is concluded that the impaired barrier function in psoriasis is not due to EFA‐deficiency.

The influence of body mass index on skin susceptibility to sodium lauryl sulphate

“…Whether or not BMI is related to other dermatologic disorders, like atopic dermatitis, hidradenitis suppurativa and dermatitis herpetiformis, is controversial (8,9,13,14). The effects of nutrition on the epidermal barrier were previously examined in mice (15)(16)(17)(18). In these studies, inappropriate nutrition led to a change in the epidermal barrier.…”

The clinical benefit of moisturizers

“…However, oral treatment and topical treatment in randomized and double‐blind studies could not support the effect on moderate psoriasis 21,22 . Topical treatment with sunflower seed oil (rich in linoleic acid) increased the level of linoleic acid of the epidermal phospholipids, but did not improve the disease or change transepidermal water loss (TEWL) 23 …”

Suppressing IL-36-driven inflammation using peptide pseudosubstrates for neutrophil proteases

“…It is generally regarded that molecules >400 Da are unsuitable for transdermal delivery 54 . However, in psoriasis patients it has been demonstrated that measures of transdermal molecular trafficking are increased 55 , 56 , thus the >400 Da cutoff may not strictly apply in this context. Furthermore, a variety of skin penetration techniques exist to overcome this obstacle including chemical techniques (e.g., permeation enhancers such as alcohols, amines, surfactants, esters, lipid-systems, or pro-drug formulations) and physical techniques (e.g., iontophoresis, electroporation, and microporation).…”