Keratin (KRT)

Keratin is a family of fibrous structural proteins that form the primary constituent of the stratum corneum, the outermost layer of the epidermis (UniProt, 2023). In the stratum corneum, keratin filaments are bundled together and embedded in a lipid matrix, providing mechanical strength and a water-impermeable barrier for the skin (StatPearls, 2023). Hyperkeratosis occurs when there is an abnormal accumulation of keratin, resulting in a thickened, often scaly or hard skin surface seen in conditions like psoriasis, ichthyosis, and common calluses (Mayo Clinic, 2024). Therapeutic intervention typically involves the use of keratolytic agents, which target the keratin structure or the desmosomal attachments between corneocytes (PubChem, 2024). These drugs, such as salicylic acid and urea, act by softening the keratin and promoting the desquamation of the excess tissue, thereby restoring normal skin texture and function (Journal of Clinical and Aesthetic Dermatology, 2021).

Other names

CytokeratinIntermediate filament proteinCorneocyte keratinHard keratinSoft keratinKeratin in hyperkeratotic stratum corneum

Keratolytic agents work by increasing the moisture content of the skin and dissolving the intercellular cement (desmosomes) that holds the cells of the stratum corneum together, or by directly denaturing and breaking down keratin filaments, thereby facilitating the shedding of hyperkeratotic scales (StatPearls, 2023; PubChem, 2024).