Home Cosmetic Science Talk Formulating Advanced Questions Cause of Sun sensitivity after glycolic acid exfoliating?

  • Cause of Sun sensitivity after glycolic acid exfoliating?

    Posted by abdullah on November 29, 2021 at 5:08 am

    What causes skin to become more sensitive to sun after applying AHA like lactic acid and glycolic acid?

    Is it because the top layer of skin has been removed by AHA exfoliant and the bottom layer is more gentle so it is more sensitive to sun?

    Or 

    When AHA exfoliant is on skin, after exposure to sun some chemical reaction is happening with AHA and that makes the skin more sensitive to light?

    vitalys replied 2 years, 3 months ago 4 Members · 9 Replies
  • 9 Replies
  • vitalys

    Member
    November 29, 2021 at 1:16 pm

    The following events occur: 
    Acid application > Damage to the corneocytes > Cytokines production begins  > Initial stages of inflammation > Activation of all lively cells in the basal layer, including melanocytes, immune cells and fibroblasts > Activated melanocytes start to produce melanin. 
      

  • paprik

    Member
    November 29, 2021 at 5:54 pm

    Funny, I was exploring this yesterday for my assessment. 
    In case you would get some really detailed info -> 

    https://ec.europa.eu/health/ph_risk/committees/sccp/documents/out121_en.pdf

  • abdullah

    Member
    November 30, 2021 at 2:29 am

    @vitalys which stage makes the skin sensitive to sun?

    And is this sensitivity only when AHA is on top of skin or even after some time when it is rinsed off? 

  • abdullah

    Member
    November 30, 2021 at 3:00 am

    @Paprik thanks for the file.

    This part was interesting. 
    In the Federal Republic of Germany, on the basis of information available to the BGVV it has been recommended that glycolic acid may be used at a level of up to 4% and a pH ≥ 3.8 and lactic acid up to a maximum level of 2.5% and a pH ≥ 5.


    isnt lactic acid more gentle than glycolic acid?
  • vitalys

    Member
    November 30, 2021 at 3:00 pm

    @Abdullah The Stratum Corneum is a pretty strong shield against sunbeams. When SC gets damaged or altered with any chemical or mechanical agent the shield becomes weak or thin, which makes lively skin cells vulnerable to solar radiation. The latter induces inflammatory reactions as well as the alterations from the damaging factors (e.g. acid peelings). 

    Abdullah said:
    And is this sensitivity only when AHA is on top of skin or even after some time when it is rinsed off? 

    The hypersensitivity will last until the skin barriers are completely restored and inflammation is eliminated. 

  • abdullah

    Member
    December 1, 2021 at 1:11 am

    vitalys said:

    @Abdullah The Stratum Corneum is a pretty strong shield against sunbeams. When SC gets damaged or altered with any chemical or mechanical agent the shield becomes weak or thin, which makes lively skin cells vulnerable to solar radiation. The latter induces inflammatory reactions as well as the alterations from the damaging factors (e.g. acid peelings). 

    Abdullah said:
    And is this sensitivity only when AHA is on top of skin or even after some time when it is rinsed off? 

    The hypersensitivity will last until the skin barriers are completely restored and inflammation is eliminated. 

    Thanks

  • abdullah

    Member
    December 18, 2021 at 4:40 am

    vitalys said:

    @Abdullah The Stratum Corneum is a pretty strong shield against sunbeams. When SC gets damaged or altered with any chemical or mechanical agent the shield becomes weak or thin, which makes lively skin cells vulnerable to solar radiation. The latter induces inflammatory reactions as well as the alterations from the damaging factors (e.g. acid peelings). 

    Abdullah said:
    And is this sensitivity only when AHA is on top of skin or even after some time when it is rinsed off? 

    The hypersensitivity will last until the skin barriers are completely restored and inflammation is eliminated. 

    @v@vitalys hey i was reviewing my questions and seeing your comment, another question came to my mind?

    After chemical exfoliant (lactic acid or glycolic acid), how many days minimum and maximum will the inflammation last?

    I mean if i am applying 10% lactic acid Evey night, does it mean my face is always in inflammation? 

  • Mayday

    Member
    December 18, 2021 at 8:21 am

    Abdullah said:

    After chemical exfoliant (lactic acid or glycolic acid), how many days minimum and maximum will the inflammation last?

    I mean if i am applying 10% lactic acid Evey night, does it mean my face is always in inflammation? 

    If true I am curious if that sort of inflammation could also be systemically bad for you, like the link between gum disease and heart disease. Skin surface is massive.

  • vitalys

    Member
    December 18, 2021 at 2:28 pm

    @Abdullah Any chemical peeling causes various degree of skin injuries and hence inflammatory response - it is the only way to get regeneration or rejuvination, etc. Most people associate inflammation with diseases or something bad and unpleasant but in fact inflammation is a double-edged sword. We can not treat any disease or condition without inflammatory process. The theory of inflammation is a cornerstone in medical sciences, including dermatology and cosmetology. The only purpose of chemical peelings is inducing the controled injury and inflammation and then the healing process, which results in skin regeneration at the area of injury with all aesthetic benefits . Generally, more tissue damage = more severe inflammation = more pronounced cosmetic effects in the end of the healing process. You may cause a single, but severe injury with free acid at high concentration (50-70% and even higher) or use diluted less concentrated solutions (or neutralized forms) repeatedly to get lesser inflammatory response and hence the moderate or even comparable cosmetic effects with time. (slowly but surely). However, continuous use of the diluted solutions (read the prolonged mild inflammation) may lead to unwanted permanent effects such as changing of a skin type, oiliness, dryness etc. In the latter case every time you apply the acid solution you induce the inflammatory response, which could be unnoticeable or insignificant, because the damage you create is insignificant. 
    It is very important to note that the strength of an acid solution is not so important as its pH. So pH defines the strength of the peeling solution, not a concentration intself. The same concentration of the acid, for instance 70% may have pH 0.1/0.2 or 2.0 or 3.5 and even higher. 
    10% of free lactic acid solution is often used as pretreatment before the serious medical grade peelings with highly concentrated acids or acid combinations. So, I assume this concentration is relatively high for every day continuous use unless you create the partially neutralized solution at the same concentration with higher pH. 
    @Mayday Yes, some peelings may cause severe systemic responses. For instance, phenolic peelings can be provided only in clinics with a control of heart and lungs functions to avoid the heart failure. 

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