Follicular keratin and sebum components (FKSC)

Follicular keratin and sebum components refer to the biological materials within the pilosebaceous unit that, when produced in excess or processed abnormally, lead to the formation of comedones and the progression of acne vulgaris. Follicular keratin consists of structural proteins produced by keratinocytes lining the infra-infundibulum, while sebum is a complex mixture of lipids including triglycerides, wax esters, and squalene produced by sebaceous glands. In pathological states, hyperkeratinization leads to the shedding of cohesive corneocytes that, when mixed with high-viscosity sebum, create a plug known as a microcomedo. This environment promotes the growth of Cutibacterium acnes and subsequent inflammation. Therapeutic intervention typically involves keratolytic agents to dissolve keratin plugs, retinoids to normalize the growth cycle of follicular cells, and sebostatic agents to reduce the lipid substrate available for bacterial metabolism and plug formation.

Other names

Follicular keratinSebumPilosebaceous unit componentsFollicular debrisMicrocomedo components

Keratolytic agents (e.g., salicylic acid) break down the intercellular desmosomes between keratinocytes to promote desquamation of follicular keratin. Retinoids normalize follicular keratinization by binding to retinoic acid receptors (RARs) to prevent the formation of microcomedones. Comedolytic agents and detergents help emulsify and remove excess sebum and cellular debris from the pilosebaceous duct.