Professor Kwon Hyuk-soo of the Allergy Department at Asan Medical Center is sounding the alarm on common hygiene habits, revealing that he strictly prohibits his own children from using standard body washes to protect their skin’s natural defenses.
Appearing recently on the YouTube channel ‘Daily Awesome’, Professor Kwon discussed the critical link between the skin barrier and allergy prevention. "Maintaining a robust skin barrier is essential for warding off allergies," Kwon explained. "To achieve this, we must foster an environment where beneficial bacteria can thrive." According to the professor, three primary factors are necessary to cultivate this healthy microbiome.
The first priority is maintaining the skin's lipid coating. Professor Kwon noted that "good" bacteria are essential to this process, as they break down various fatty acids to produce glycerol. This glycerol then penetrates the skin to reinforce the barrier, creating a virtuous cycle of hydration and protection.
However, the professor warned that the pH of the skin is the deciding factor in whether these bacteria survive. "Nearly all foaming soaps are strongly alkaline," Kwon pointed out, identifying them as a major threat. "If you scrub your skin with alkaline soap, the beneficial bacteria are washed away, stripping the skin of its natural protection. Strong foaming soaps are the worst thing for your barrier."
For those looking to improve their routine, Kwon’s advice is straightforward: "Eliminate strong body washes and soaps from your bathroom entirely. Instead, switch to neutral or mildly acidic cleansers."
The Lipid Layer: A Shield Against Irritants and Moisture Loss
The skin’s lipid layer serves a dual purpose: it prevents moisture from evaporating and acts as a primary defense against external irritants. When this layer is compromised, moisture escapes rapidly, leading to micro-cracks and chronic dryness. This often triggers intense itching; when a person scratches, they enter a "vicious cycle" of further tissue damage and inflammation.
A weakened lipid layer also provides a gateway for external allergens to penetrate the skin. Medical research has long established that a deterioration in skin barrier function is a leading cause of atopic dermatitis and other chronic inflammatory responses.
Why Scrubbing is "The Worst Thing in the World"
Beyond chemical irritants, Professor Kwon warned that physical exfoliation is equally destructive. "Scrubbing is the worst thing in the world for your skin," he stated bluntly. "It causes direct trauma to the surface and destroys the barrier you are trying to protect."
Repetitive friction from scrubbing can lead to irritant dermatitis, a risk that is significantly higher for patients with atopic dermatitis whose barriers are already fragile.
For a safer cleanse, Professor Kwon recommends a "foam-only" approach. Using a mildly acidic soap, one should create a rich lather using a washcloth or towel, gently apply only the foam to the skin, and rinse it off within one minute. This method removes surface dirt without stripping away the essential oils and bacteria that keep the skin healthy.
