Itching All Over and Flaking Skin Every Autumn and Winter? Why Your Skin Reacts to the Seasons

The influence of the movements and qi of heaven and earth and dryness described in the Donguibogam closely aligns with modern medicine's understanding of weakened skin barrier function. During autumn and winter, falling temperatures and dropping humidity place significant stress on the stratum corneum, the skin's outermost layer. The stratum corneum is composed of keratinocytes arranged like bricks and intercellular lipids such as ceramide, cholesterol, and fatty acids that bind them like mortar, acting as a crucial skin barrier that deflects external irritants while sealing in internal moisture. When exposed to dry conditions, these lipid components break down, causing the barrier to fail. As a result, transepidermal water loss surges as internal moisture rapidly evaporates, allowing external irritants and allergens to penetrate more easily. This triggers an inflammatory response in skin cells and prompts the release of mediators like histamine that provoke pruritus. Pruritus does not stem solely from dryness; it also sensitizes nerve endings, making them overreact to even slight stimulation. People with atopic dermatitis, who naturally have a compromised skin barrier, are especially vulnerable to this dryness and frequently experience seasonal flare-ups. In addition, indoor heating significantly worsens xerosis cutis. Warm air further dries the ambient environment, while hot showers strip away the protective surface lipids, leaving the skin even more delicate. Just as the Donguibogam notes that the lung governs the skin, contemporary medicine also focuses on the close communication between the skin immune system and systemic immunity. With ongoing research uncovering the gut-skin axis and how stress alters immune responses, modern science increasingly views skin health not in isolation, but as part of overall systemic balance.