Skin Care and Esthetics
Structure and function
The epidermis has five layers - stratum corneum, lucidum (palms and soles), granulosum, spinosum, and basale, where new cells form. The dermis holds collagen and elastin; the subcutaneous layer provides fat and insulation. The acid mantle sits near pH 4.5–5.5 and defends against bacteria. Know the Fitzpatrick scale (I–VI) for sun and waxing risk, and the basic skin types: normal, dry, oily, combination, sensitive. Dehydration means lack of water; dryness means lack of oil - questions love to swap them.
Treatments and ingredients
Massage manipulations: effleurage, petrissage, tapotement, friction. Chemical exfoliants: AHAs such as glycolic and lactic acids suit dry, mature, sun-damaged skin; BHA (salicylic acid) suits oily and acne-prone skin because it is oil soluble. Physical scrubs and enzyme masks have their place but must be matched to sensitivity. Estheticians cannot diagnose or treat disease; acne, rosacea, and dermatitis are medical conditions requiring referral.
Contraindications
Isotretinoin (Accutane), retinoids, recent peels, laser work, and blood thinners are classic waxing and exfoliation contraindications. Patch test brow and lash tints 24–48 hours ahead. Sanitize hands, drape properly, and disinfect implements between clients.
Worked example
An oily, congested client books a facial. Rather than a rich glycolic cream, choose a salicylic-based exfoliant, light noncomedogenic hydration, and steam-assisted extraction only on noninflamed lesions - inflamed or cystic lesions are referred out. The trap is choosing the strongest acid rather than the acid that matches the skin type.