Why we need to keep the skin at pH5.5?

Why we need to keep the skin at pH5.5?

The pH scale ranges from 1 to 14,with 7 considered as  “neutral” .The numbers below 7 are acidic, while above 7 are considered alkaline.


The skin tends to have a broad pH range, with acidity ranging between 4 and 7.(1)  Studies have shown that a healthy skin pH is more acidic, that is below 5.


Dr. Ellis Hon, Professor of Practice in Paediatrics (by courtesy), Department of Paediatrics, Faculty of Medicine, CUHK pointed out that Staphylococcus Aureus is a common bacterium on the surface of the skin. About 5% of people are detected to have Staphylococcus Aureus on the skin while the rate in eczema patients is as high as 70%. When the skin microbiome is out of balance, the chances of Staphylococcus Aureus reproduction increase. The high concentration of Staphylococcus Aureus can form biofilms and produce super-antigens, toxins and proteins that cause skin discomfort or flare-ups.

A Harvard Medical School study indicates that Staphylococcus Aureus bacteria release compounds that interact with nerve cells, leading to itchiness. Inhibiting bacterial growth in a mildly acidic environment can help alleviate this itching.


(2) Eczewear products are designed to be eczema-friendly as we care the impact of clothing on the skin pH.  The use of Comfiknit Atopic Eczema® fabric provides a pH 5.5 condition for the skin, creating an environment that is unfavorable for bacterial growth, thereby reducing itchiness.  Acidity also promotes skin’s self-repair.

Skin pH varies with ages.  The average newborn has a skin pH of 7 while the average adult skin pH is 5.7.

Skin pH varies depending on the area of your body too. The lesser exposed areas, such as the buttocks, armpits, and genital area tend to have a higher acidity.


(3) Other factors that can affect skin pH include: 

  • Sebum and skin moisture
  • Sweat ( is slightly more acidic than blood )
  • area of the body
  • genetics and age
  • detergents
  • skincare products and cosmetics
  • antibacterial products like soaps and gels
  • certain skin conditions


Source of information:

(1) https://pubmed.ncbi.nlm.nih.gov/18489300/

(2)  https://hms.harvard.edu/news/new-clues-head-scratching-mystery-itch
(3) https://www.healthline.com/health/whats-so-important-about-skin-ph#skin-p-h

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