exaggerated by exposure to multiple environmental insults including change of season to colder ambient temperatures, low and high ambient humidity variations, pollutant exposure, routine skin cleansing and skin care product regimens. Certain alcohols, vitamin A and C derivatives and hydroxy acids usually exist in marketed anti-aging products at barrier damaging and pro-inflammatory concentrations. Exposure to heavy metals such as nickel, gold, chromium, and lipid-lowering medications also inhibit repair of SCPB as well as damage it like UV-light (UVL). Other barrier damaging environmental insults include prolonged air travel (>4–6 hours), severe emotional and physical stress, and severe dietary lipid restriction. Auto-immune diseases such as atopy, diabetes, lupus erythematosus, and certain other collagen vascular diseases are characterized by atrophic skin compromised SCPB and exaggerated chronic inflammation. Photoaging and eleven other cutaneous diseases and conditions are also characterized by these same two anomalies of a compromised SCPB and excessive chronic inflammation as listed in Table 15,6
.
The damaged SCPB allows the previously mentioned environmental insults to increase the amount and depth of mucocutaneous penetration by orders of magnitude. In turn, inflammation severity and depth are enhanced. All sunscreen ingredients labeled by the FDA bind to
stratum corneum corneocytes, lipids, and epidermal stratum granulosum cells. Therefore, a compromised stratum corneum is associated with significantly reduced binding of the sunscreen molecules at the active anatomic site. A further significant reduction of photoprotection occurs. It is intuitive that application of a barrier repairing product to the skin prior to sunscreen application would also be expected to significantly improve sunscreen protection. International regulatory bodies, including the FDA, recommend photoprotection when topically applied hydroxy acids, retinoids, and benzoyl peroxides are used chronically due to concerns of increased radiation injury, including neoplasia.
Hydration and transepidermal water loss Moisturization or hydration does not correlate with SCPB function; therefore, using any lotion or cream which by definition are more than 50% water
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96