Group 1: Skin Types and Identification - Healthy skin is categorized into four types: oily, normal, dry, and combination, with most adults over 25 having either oily, dry, or combination skin [2][3] - To identify skin type, a gentle cleanser is used, followed by observation after 1-2 hours: oily skin shows shine, dry skin feels tight and may flake, and combination skin has an oily T-zone but dry cheeks [3][5] Group 2: Cleansing and Moisturizing Recommendations - Oily and combination skin can be cleansed twice daily, while normal and dry skin should cleanse once at night and use water in the morning, adjusting frequency in summer [5] - For moisturizing, oily and combination skin should use lightweight products to avoid clogged pores, while normal and dry skin should adjust products based on the season [5] Group 3: Sunscreen Selection and Usage - Different skin types require specific sunscreen choices: oily skin benefits from chemical sunscreens, while dry and sensitive skin should opt for physical sunscreens [7] - Sunscreen should be applied at least 15 minutes before sun exposure and reapplied every two hours during high activity [8] Group 4: Special Considerations for Vulnerable Groups - Special populations such as the elderly, pregnant women, and sensitive skin individuals should prioritize physical sun protection methods and use less irritating sunscreens [10] - Infants under six months should avoid sunscreen, relying on physical shade, while those over six months can use baby-specific sunscreens [10] Group 5: Misconceptions about Moisturizing Masks - The effectiveness of moisturizing masks is limited as they primarily hydrate the skin's surface and do not significantly enhance hydration [11][12] - Increased mask usage is recommended post-light therapy treatments, with a preference for medical-grade masks that are free from fragrances and preservatives [14]