WA Master Esthetician key terms

A six-point scale that classifies skin by melanin content, tendency to burn, and ability to tan. Estheticians use it to estimate photodamage risk and to select safe device and peel settings.

A filtered ultraviolet light used in a darkened room to reveal surface and subsurface skin conditions, which fluoresce in characteristic colors. It helps identify dehydration, pigmentation patterns, and bacterial or fungal presence.

A structured questionnaire and interview documenting medications, allergies, pregnancy, surgeries, and skin conditions before treatment. It is the legal record that supports informed consent and contraindication screening.

The largely unchanging, genetically determined classification of skin as normal, dry, oily, or combination, based on sebum output and barrier behavior. It is distinct from a skin condition, which is temporary and treatable.

The outermost stratum corneum together with its lipids, which limits water loss and blocks irritants, allergens, and microbes. When compromised, clients report tightness, stinging, and redness, and active ingredients penetrate more aggressively.

A cell in the basal layer of the epidermis that produces melanin and transfers it to nearby keratinocytes. Its activity determines baseline pigmentation and drives responses such as darkening after inflammation or injury.

A dermal cell that synthesizes collagen, elastin, and glycosaminoglycans. Modalities such as microneedling and radiofrequency aim to stimulate fibroblast activity to improve firmness, thickness, and texture.

The slightly acidic surface film of sebum, sweat, and cellular debris, normally near pH 4.5 to 5.5. It supports barrier enzymes and discourages pathogens, and alkaline cleansers can disrupt it.

The time required for keratinocytes to move from the basal layer to shedding at the surface, roughly 28 days in young adults. It slows with age and photodamage, producing dullness and congestion.

A gland attached to a hair follicle that secretes sebum to lubricate skin and hair. Its activity is hormone-driven, concentrated in the T-zone, and overactivity contributes to congestion and acne.

A measure of acidity or alkalinity on a zero-to-fourteen scale that governs how an ingredient behaves on skin. Low pH favors exfoliating acids, while formulas near skin pH suit sensitive or barrier-compromised clients.

An ingredient such as glycerin or hyaluronic acid that binds water and draws it into the stratum corneum. It improves hydration and pliability but generally needs an occlusive layer to prevent moisture loss.

A substance such as vitamin C, vitamin E, or niacinamide that neutralizes free radicals generated by ultraviolet light and pollution, helping limit collagen breakdown and pigment formation. It is best applied before sun exposure.

Water-soluble acids such as glycolic and lactic acid that loosen bonds between dead surface cells, promoting exfoliation and smoother texture. Their effect depends on concentration, pH, and contact time.

Salicylic acid, a lipid-soluble exfoliant that enters pores to dissolve sebum and debris. It suits oily and acne-prone skin, and aspirin allergy is a contraindication.

A caustic peel acid that coagulates proteins in the epidermis and dermis, producing depth-related frosting and peeling. Higher concentrations carry greater risk of scarring and pigmentation and exceed basic esthetic scope in many settings.

A classic superficial peel combining resorcinol, salicylic acid, and lactic acid in ethanol. Resorcinol can affect thyroid function and cause pigmentation, so screening and short contact times are essential.

An alkaline solution, usually based on sodium bicarbonate or sodium hydroxide, applied to stop an acid peel at the intended depth. Prompt, complete application prevents overexfoliation, burning, and pigment injury.

Whitening of the skin during a peel caused by protein coagulation in the epidermis. Light, patchy frosting signals superficial depth, while dense solid white indicates deeper injury requiring immediate cessation and cooling.

The natural or treatment-induced shedding of corneum cells in flakes or sheets after exfoliation. Mild flaking is expected after a peel, but prolonged or painful peeling suggests barrier damage.

Darkened patches that follow inflammation or injury to the skin, most common in medium to deep skin tones. Prevention depends on controlling inflammation and avoiding aggressive treatment of reactive skin.

The principle that a light device can injure one target while sparing surrounding tissue when wavelength, pulse duration, and fluence are matched to that target. It underlies safe laser hair removal and vascular treatment.

A molecule in tissue, such as melanin, hemoglobin, or water, that absorbs particular wavelengths of light and converts them to heat. Matching wavelength to the intended chromophore determines a device's clinical effect.

A non-laser device that emits broadband light through filters to treat pigmentation, redness, and unwanted hair. Because the light is neither coherent nor collimated, results depend on filter choice, skin type, and operator skill.

The energy delivered per unit area, usually stated in joules per square centimeter. Higher fluence increases both effect and risk, so settings must match skin type, treatment site, and device specifications.

The time a heated target structure needs to cool to half its peak temperature after absorbing light. Pulses shorter than this value confine heat to the target, which is essential for selective damage.

Wavelength-specific eyewear, shields, or goggles worn by client and operator during light-based treatments. They prevent retinal and corneal injury from direct, reflected, or scattered light.

A technique using fine needles to create controlled punctures in the skin, triggering collagen remodeling and enhancing product penetration. Needle depth, device hygiene, and client screening determine safety and outcome.

The intended result of controlled micro-injury, in which wound healing stimulates new collagen and elastin in the dermis. Improvement develops over weeks and usually requires a series of sessions.

A modality that delivers electrical current to heat dermal tissue, contracting existing collagen and stimulating new production. Depth and risk depend on the device, energy settings, and the client's skin condition.

Mechanical exfoliation with crystals or a diamond-tipped handpiece that removes outer corneum cells. It suits dullness and mild texture but should be avoided on active acne, rosacea, and compromised skin.

The complete destruction of all microorganisms, including spores, usually by autoclave or dry heat. It is required for items that penetrate skin or contact blood, such as reusable needles and extraction tools.

An EPA-registered product carrying label claims against specified pathogens, used on nonporous surfaces and tools that cannot be sterilized. The label contact time must be followed exactly for the product to work.

Infection-control practices applied to every client regardless of known health status, including hand hygiene, gloves, and barrier protection. They assume any blood or body fluid may carry infectious organisms.

A documented discussion in which the client learns the procedure, its risks, alternatives, and aftercare, then agrees voluntarily to proceed. It protects both client and provider and must be obtained before treatment begins.

The legally defined services, devices, and treatment depths a licensed professional may perform under Washington statute and administrative rules. Exceeding it risks client harm and professional discipline.

A small controlled application of a product to a discreet area, observed for 24 to 48 hours to detect sensitization before full treatment. It is especially important with peel acids, dyes, and adhesives.

A delayed hypersensitivity reaction producing redness, swelling, itching, and sometimes blisters where a substance contacted skin. It may appear hours to days after exposure and requires discontinuation of the product and referral.

An overgrowth of scar tissue that extends beyond the original wound, seen more often in darker skin and on certain body sites. A personal history of keloids is a contraindication for microneedling and deeper peels.