Advanced Diploma of Skin Therapy key terms

The outermost layer of the epidermis, made of flattened, keratin-filled cells that form the skin's main barrier against water loss, irritants, and microorganisms.

The combined protective role of the skin's outer layers, including physical, chemical, and immunological defences that keep irritants out and moisture in.

The measurable amount of water that evaporates through the skin surface, used as an indicator of barrier integrity and hydration status.

The natural shedding of dead surface skin cells as the bonds between them break down, a process that slows in dry or aged skin.

A cell in the basal epidermis that produces melanin pigment and transfers it to nearby keratinocytes, determining skin and hair colour.

A cell in the dermis that synthesises collagen, elastin, and ground substance, maintaining skin structure and supporting wound repair.

A gland attached to a hair follicle that secretes sebum, an oily substance that lubricates skin and contributes to acne formation when overactive.

A six-point classification of skin based on colour and its tendency to burn or tan, used to estimate photodamage and treatment risk.

The categorisation of skin as normal, dry, oily, combination, or sensitive based on oiliness, hydration, and reactivity observed during analysis.

A temporary or treatable state such as dehydration, acne, or sensitivity that differs from a fixed skin type and guides product and treatment choice.

A blocked hair follicle filled with sebum and dead cells; open comedones darken at the surface while closed comedones remain covered by skin.

Darkened patches left after inflammation or injury to skin, caused by excess melanin production and more common in deeper skin tones.

A client's voluntary agreement to a treatment after receiving clear information about its nature, benefits, risks, alternatives, and costs.

A condition, medication, or circumstance that makes a treatment unsafe or inadvisable, either absolutely or only under certain precautions.

A small controlled application of a product or ingredient to check for an allergic or irritant reaction before a full treatment.

An unwanted reaction or injury arising during or after a treatment, which must be documented, managed, and reported according to policy.

A written account of a client's consultation findings, products used, settings, outcomes, and aftercare advice, kept for legal and clinical reference.

A structured documentation format recording subjective client reports, objective observations, assessment of findings, and the plan for future care.

A structured conversation before treatment that gathers health history, expectations, and lifestyle information to build a safe, suitable treatment plan.

Systematic examination of the skin using observation and touch, sometimes with tools, to identify type, condition, and treatment needs.

An ultraviolet light device used in skin analysis to reveal fluorescence patterns that can indicate dehydration, pigmentation, or bacterial activity.

Application of an acid solution to remove controlled layers of skin, improving texture, pigmentation, and acne while requiring careful client selection.

A whitening of the skin surface during a chemical peel that signals protein coagulation and indicates the depth of peel achieved.

The process of stopping an acid peel by applying a neutralising agent, followed by removal, to prevent excessive penetration and injury.

A technique using fine needles to create controlled micro-injuries in the skin, stimulating collagen production and improving scars and texture.

The ongoing breakdown and rebuilding of collagen fibres in response to injury or ageing, which gradually changes skin firmness and texture.

The staged sequence of inflammation, tissue formation, and remodelling that the body follows to repair skin after injury or controlled damage.

A device emitting broad-spectrum light pulses absorbed by pigment and blood vessels, used for hair reduction and some skin rejuvenation.

The principle that light energy can target a specific structure such as pigment or a vessel while limiting damage to surrounding tissue.

Injection of a purified neurotoxin that temporarily reduces muscle movement to soften dynamic wrinkles, requiring prescriber oversight and aftercare advice.

An injectable gel, often hyaluronic acid based, placed in or beneath the skin to restore volume and smooth contours.

The routine washing or sanitising of hands at defined moments to prevent transferring microorganisms between clients, surfaces, and the practitioner.

Baseline infection control measures applied to every client, including hand hygiene, gloves, and safe handling of blood and body fluids.

A process that destroys all microorganisms, including spores, on reusable instruments, usually by autoclave before storage and reuse.

The boundaries of tasks and decisions a practitioner is trained, insured, and legally permitted to perform within their professional role.

Directing a client to another qualified professional when their needs exceed the practitioner's competence, scope, or available resources.

Coverage that protects a practitioner against claims of negligence or harm arising from treatments delivered within their insured scope.

The ethical and legal duty to keep client information private, sharing it only with consent or where required by law.

Instructions given after treatment about skincare, sun protection, and warning signs, helping clients manage recovery and recognise complications.