Keratin and other skin surface components

Keratin and other skin surface components, primarily located within the stratum corneum, constitute the body's essential physical and chemical barrier against environmental pathogens, dehydration, and mechanical stress (StatPearls, 2023). Keratins are a group of fibrous structural proteins that form intermediate filaments, providing mechanical stability to keratinocytes, while other components such as ceramides, cholesterol, and free fatty acids form a lipid matrix that prevents transepidermal water loss (NCBI, 2022). In pathological states like psoriasis, ichthyosis, or keratosis pilaris, there is an abnormal accumulation of keratin (hyperkeratosis) or a failure in the desquamation process, leading to thickened, scaly skin (PubMed, 2021). Therapeutic strategies targeting these components often utilize keratolytic agents, such as salicylic acid, urea, or alpha-hydroxy acids, which work by disrupting the adhesion between corneocytes or by softening keratin through hydration (PubChem, 2024). While these treatments are effective for managing hyperkeratotic disorders, they can lead to side effects such as skin irritation, increased sensitivity to ultraviolet radiation, and temporary impairment of the skin's protective barrier (NIH, 2023).

Other names

Stratum corneum componentsEpidermal keratinsSkin barrier proteinsCorneocyte componentsSurface keratinsSkin surface lipids

Keratolytic agents act by increasing the moisture content of the skin and dissolving the intercellular cement (desmosomes) that binds corneocytes in the stratum corneum, thereby facilitating the shedding of skin cells (StatPearls, 2023). Some agents specifically target the hydrogen bonds in keratin proteins to soften the skin surface and improve texture (PubChem, 2024).