5-fluorouracil (5-FU) A chemotherapy agent that is given as a treatment for some types of cancers; used as a topical peeling agent; also known as Efudex when used on the skin

Acetic acid A mild organic acid derived from vinegar.

Acetylcholine An enzyme found at the neuro muscular joint. Involved with muscle movement.

Acid Mantel – a thin coating on the stratum corn rum that protects the skin from infection. It has a ph of 4.0 – 6.5

Acidic – any substance that has a ph of less than 7

Actinic keratosis – Precancerous lesions of the skin, generally from sunlight exposure.

Adipose cells – fat cells

Alkaline- any substance that has a ph over 7.0

Alpha arbutin – skin brightener derived from plants such as blueberries and cranberries. Helps to fade scarsand pigmentation.

Alpha hydroxy Acids – Mild organic acids used in cosmeceutical products. AHAs “unglue” cells in the epidermis, allowing keratinocytes to be shed at the stratum granulosum, providing skin with a healthier texture.

Anthranilates- Weak UVB filters. They absorb mainly in the near UVA portion of the spectrum.

Antimicrobials – An agent that halts or prevents the development of microorganisms.

Antioxidants – Helps to maintain the skin’s barrier function by fighting off free radicals that can contribute to disease and the ageing process.

Apocrine sweat glands – the larger of the two sweat glands that are housed in axillary, pubic and perianal areas.

Appendages- any anatomic structure that’s associated with a larger structure. For the skin it’s appendages include hair follicles, sweat glands and nails.

Ascorbyl Palmitate – a fat soluble form of ascorbic acid

Atopic dermatitis – a skin irritation or rash of unknown origin.

Atrophic – to undergo deterioration 

Atrophic Scars – flat, small, round and generally inverted scars, usually seen in acne or chicken pox scarring.

Avascular – Lacking in blood vessels and thus having a poor blood supply.

Azelaic Acid – Anti-inflammatory ingredient derived from grains useful for killing off acne bacteria and reducing inflammatory conditions such as rosacea.

Bakuchiol – despite being structurally different, bakuchiol is thought to have similarr benefits to retinol without the negative side effects. It has anti-inflammatory, antioxidant and anti-bacterial properties.

Basal Cell Carcinoma (BCC) – A slow-growing tumour that generally does not metastasise. It is the most common form of skin cancer, which usually occurs in areas of repeated sunburn

Basophils – A type of white blood cell

Bearberry – A botanical used in skincare products and peeling agents to treat hyperpigmentation.

Benzophenone – A chemical absorber that responds to UV light by generating a free radical capable of rapid polymerisation.

Beta Hydroxy Acid – An isometrically distinct relative of alpha hydroxy acid

Beta Peel – A 20% or 30% salicylic acid peel solution

Blackheads or Comedones – pores blocked with sebum that when oxidised turn black in colour hence the name.

Caffeine – anti-inflammatory and antioxidant properties.

Camphor – Used topically as an anti-itching agent. Derived as a gum from evergreens native to China and Japan.

Carbon Dioxide (CO2) Laser – Aggressive type of laser used for skin resurfacing that vaporises skin and caused thermal injury allowing for improved collagen production.

Cautery – Tissue destruction, usually done using electricity.

CBD – Antioxidant, anti-inflammatory and moisturising properties. Encourages skin to produce lipids.

Cellulitis – A potentially serious infection of the skin.

Ceramides – A class of lipids that do not contain glycerol cholesterol.

Chemical Peeling – The use of chemical agents to destroy layers of the skin.

Chemoexfoliants – The use of chemical agents to exfoliate the stratum corneum 

Cholesterol – A precursor to most steroid hormones; a single molecule is called alcohol.

CICA – helps reduce inflammation and irritation. Rich in amino acids, fatty acids and antioxidents.

Cinnamates – A derivative of cinnaminic acid useful for protection against low levels of UVB rays. Also makes sunscreens waterproof.

Citric Acid – An AHA derived from citrus fruit such as oranges and grapefruit.

Collagen – An insoluble protein found in connective tissues. Particularly, type 1 collagen forms a network in the epidermis, and it is credited with providing skin with its tensile strength and firmness.

Cornified – Hardening or thickening of the skin. 

Cosmeceutical – products that do more than decorate or camouflage but less than prescription medication would do.

Croton Oil – A fixed oil extracted from the croton plant (castor oil). 

D-alpha tocopherol – An antioxidant 

Deep epidermal wounding – an injury that reaches deep into the epidermis, as with peeling solutions.

Deep peels – a peel depth extending into the papillary dermis or upper reticular dermis. Most notable of deep peels are phenol.

Defatted – The use of isopropyl alcohol or acetone to remove all oils from the skin which allows peel solutions to work evenly.

Dermal-epidermal Junction – The superficial side of the dermis, connected to the epidermis.

Dermaplaning – The use of a sharpe blade to exfoliate the stratum corneum.

Dermis – The second layer of skin responsible for attaching the skin to the body.

Desmosomes – Small hairlike structures in the spiny layer of the epidermis.

Dibenzoylmethanes – A UVA Ray absorber.

Discoid lupus – Cyclic breakouts and remissions of a scaly red rash

Dynamic Rhytids – Wrinkling that occurs as a result of facial movement.

Dyschromia – Discolouration of the skin

Eccrine Sweat Glands – The smaller of the two sweat glands that reside all over the body.

Elastin – Connective tissue proteins

Emollients – A product that has a softening or soothing effect on the skin.

Eosinophils – Granulocyte blood cell characterised by multi-shaped nuclei; present in full thickness wounds.

Epidermal Cells – Cells found in the outer most layer of skin.

Epidermal Growth Factor – A protein that stimulates cell growth.

Epidermis – Outermost, avascular, protective layer of skin.

Epidermolysis – Separating of the epidermal cells.

Epithelialisation – The growth of new skin over a wound.

Epithelium – Membranous tissue covering internal organs and lining skin appendages.

Eribium Laser – Type of laser that causes less thermal injury than a CO2 laser while still causing epidermal and papillary dermal injuries.

Erythema – A spot on the skin showing diffused redness caused by capillary congestion and dilation.

Ester – a fragrant water and fat soluble compound formed by the combination of an organic acid and alcohol removing water from the compound.

Exfoliation – The process of removing dead skin cells from the outer most layer of the skin; very superficial and superficial peels are exfoliants rather than true peels.

Fatty Acids – One of many molecules that are long chains of lipid-carboxlic acid found in fats and oils.

Filaggrin – Synthesises lipids (fats) that are thought to serve as “intercellular cement” an important component of NMF.

Fitzpatrick Skin Typing – A method of skin typing that considers skin’s complexion, hair colour, eye colour, ethnicity, and the individuals reaction to unprotected sunlight exposure.

Folliculitis – An infection of the hair follicle, such as ingrown hairs.

Four Humours – Early medical concept that states the character of a man is determined by the specific balance of the four fluids running through the body: black bile, yellow bile, blood and phlegm.

Free Radicals – Molecules lacking an even number of electrons. Free radicals play an important role in tissue ischemia, injury and ageing.

Frost – Coagulation of protein in the skin that turns the skin a white colour.

Full Thickness Wounds – Wounds that penetrate to a specific depth in the papillary dermis of upper reticular dermis. These wounds are associated with slower healing and scarring will usually develop.

Generalised Post Traumatic Dyschromia – Hyperpigmentation caused by an insult.

Ginseng – A herbal remedy with antioxidant and anti-inflammatory properties.

Glabella – The area in between the eyebrows.

Glycolic Acid – Alpha Hydroxy Acid derived from sugar cane. It has a small molecular size that allows for easier penetration into the skin.

Glycosaminoglycans (GAGs) – Polysaccharide chains, mist prominent in the dermis that bind with water, smoothing and softening the surface from below.

Granulocytes – White blood cells involved in immune response; these include neutrophils, eosinophils, and basophils.

Hemochromatosis – Dyschromia characterised by a build up of pigments; known as hemosiderosis.

Herpes Simplex (cold sores) – An infectious disease caused by herpes simplex virus (HSV-1), characterised by thin walled vesicles that tend to occur repeatedly in the same place on the skin’s surface.

Humectants – Moisturising agents

Hyaluronic Acid – An individual molecule of HA can hold 1000 times it’s own weight in water and is used in skincare to enhance hydration levels. HA is also used for dermal fillers.

Hydroquinone – A safe topical bleaching agent that inhibits the production of tyrosine within melanocytes.

Hyper pigmentation – The over production of melanin.

Hypertrophic Scar – Overly developed scar tissue that rises above the skin level, often over fed by an abundance of capillaries. These scars usually regress over time.

Hypodermis – a layer of subcutaneous fat and connective tissue lying beneath the epidermis.

Hypo pigmentation – Lack of melanin production

Impetigo – A skin infection from staphylococcal or streptococcal bacterial.

Inflammatory phase – The early wound healing phase during which blood and fluid collect and substances begin to fight infection and promote healing.

Integumentary System – The skin and it’s appendages (nails, hair, sweat glands and oil glands).

Ischemia – A localised restriction of blood flow usually caused by an obstruction of normal circulation.

Isohexadecane – A highly emollient cleansing agent.

Jessner’s Solution – Peel solution for the skin that is 14% resorcinol, 14%salicylic acid, and 14% lactic acid in ethanol.

Keloid Scars – Scar formation in which tissue response is excessive in relation to normal tissue repair.

Keratinisation – The process keratin cells go through as they move up to the stratum corneum.

Keratinocyte – Any cell in the skin, hair or nails that produces keratin.

Keratolysis – Separation of the skin cells in the epidermis.

Keratoses – Horny growths on the skin.

Kojic Acid – A bleaching agent derived from bacteria on a Japanese mushroom; most often used in conjunction with hydroquinone or as a stand alone product.

Kola Nut – An African nut tree commonly used for its strong medicinal qualities; also contains high levels of caffeine.

Lactic Acid – An AHA derived from milk.

Lamellar Granules – Control lipids that produce NMF.

Lamellar Ichthyosis – An inherited skin disorder with scaly dry patches of skin; also known as fish scale disease.

Langerhans Cells – Cells that are intimately involved in the immune response of the skin.

L-ascorbic Acid – Topical vitamin C that is both water and fat soluble.

Lentigines – Flat brown spots appearing on aged or sunlight-exposed skin. Commonly called liver spots they are not related to any liver disease.

Leukocytes – White blood cells involved in immune response. These include lymphocytes and monocytes.

Lichen Simplex Chronicus – Itching papules; also known as Vidal’s disease.

Lipids – Fat or fatlike substances that are descriptive, not chemical.

Lipodystrophy – A disruption in fat metabolism.

Lymph – 

Lymphatic Drainage – Drainage of lymphatic fluids.

Lymphocytes – White blood cells involved in the body’s immune system; their numbers increase in the presence of infection.

Macrophages – Part of the immune system in the skin; these cells are scavengers that clear debris in tissue injury.

Magnesium Ascorbyl Phosphate – An ester that converts to vitamin C on the skin.

Malic Acid – An AHA derived from apples.

Melanin – Cells that produce colour in the skin.

Melanocytes – A group of cells in the epidermis that produce the pigment – melanin 

Melasma – An over production of melanin.

Melasma Gravidarum – An increase in melanin production caused by pregnancy.

Milia – A small, white headed cyst filled with keratin.

Natural Moisturising Factor (NMF) – A compound found only in the top layer of skin that gives cells their ability to bind with water.

Necrosis – Death of cells when tissue is deprived of blood supply.

Neutral – pH of 7.0

Neutralisation – A process by which active agents lose their potency, either with the addition of another agent or the loss of time.

Neutrophils – The most common type of white blood cells that kill bacteria and discourage infection.

Nicotinamide/niacinamide – A member of the vitamin B family that has been shown to decrease TEWL.

Non Surgical Aesthetic Skincare – Any non-invasive procedure that is intended to improve overall skin health and appearance.

Occlusion – The state of being closed.

Papillae – Projections of any kind; in the skin, hold the dermis and the epidermis together.

Papillary Dermal Wounding – an injury to the skin that is sufficient to cause bleeding.

Papules – Tiny red spots that don’t form a head. 

Partial Thickness Injuruy – A wound that penetrates only the epidermis or the upper layer of the papillary dermis. These wounds tend to heal more quickly and with less risk of scarring.

Peel Depth – The depth of skin injury by chemical peeling agents.

Peel Percentage – The amount of bioavailability of the active ingredient; not to be confused with pH.

Peptides – These are short chain amino acids and are used in skincare to reinforce the proteins that naturally occur in the skin. There are hundreds of different types of peptides with a variety of functions including maintaining a healthy skin barrier, and increasing hydration.

Poly Hydroxy Acids – Larger molecules means that these don’t penetrate the skin as deeply as AHA’s & BHA’s and are therefore more suited to sensitive skins.

pH Potential of Hydrogen – The scale by which a material is characterised as being acidic (pH of less that 7.0) , alkaline (greater than 7.0) or neutral (7.0).

Phenol (carbolic acid) – Highly corrosive acid used in peel solutions that dissolves cells to make room for newer healthier ones.

Photo damage – Damage caused by repeated and unprotected exposure to sunlight over time, also called solar damage.

Pilosebaceous unit – Hair follicle and accompanying sebaceous glands and arrector pili muscle.

Prebiotics – A food source for probiotics that help to increase the amount of probiotics and lead to a healthy skin barrier and improved hydration.

Probiotics – The good bacteria that lives in our skin and is essential for maintaining skin health.

Post inflammatory Hyperpigmentation – Pigment that occurs in response to skin injury.

Proliferative Phase – The phase of wound healing during which replacement of protective epithelial tissue occurs over the old wound site.

Protein – A class of complex compounds that are synthesised by all living creatures. Proteins are broken down into amino acids for use, including rebuilding of tissue.

Protein Coagulation – The point at which the peel solution reaches the protein of the skin.

Pseudofolliculitis Barbae – In-grown hairs

Pustules – Spots that contain pus.

Pyruvic Acid – An alpha keto acid that has properties of acids and keytones. Pyruvic acid is a powerful peeling agent.

Radio Frequency – Frequency used with the latest technology for promoting collagen growth.

Reepithelialisation – The replacement of protective epithelial tissue.

Remodelling Phase – Phase of wound healing during which collagen is assembled to replace skin.

Reservatrol – This is a naturally occurring powerful antioxidant.

Resorcinol – Equal parts of hydroquinone and catechol; a peeling agent with similarities to phenol.

Rete-pegs – Anatomic features that hold the dermis and epidermis together.

Reticula – a net like formation or structure; a network.

Reticular Dermis – The sublayer of the dermis that connects the dermis to the epidermis and is home to the skin’s appendages.

RetinA – Topical vitamin A also known as tretinoin.

Retinol – A vitamin A derivative that must first convert to retinoic acid before it can be useful to the skin.

Retinyl palmitate – A vitamin A derivative that must first convert to retinoic acid before it can be useful to the skin. It’s also thought to be useful for collagen synthesis.

Rhytids – Wrinkles

Rolling Acne Scars – Acne scars that appear in a wave pattern over the face

Rosehip Seed oil – Rich in vitamin C, E and fatty acids. Regenerates damaged skin and is suitable for oily/acne skin.

Salicylates – A salt derivative of salicylic acid used as a chemical agent in sunscreens.

Salicylic Acid – Beta Hydroxy Acid (BHA) used in the treatment of acne.

Sebaceous Glands – Small glands usually located next to the hair follicles in the dermis. They release fatty liquids (sebum) onto the hair follicle to soften the hair and skin.

Seborrheic Keratosis – A benign skin tumour common in older adults, thought to develop from prolific epidermal cells.

Sebum – The semi fluid secretion of the sebaceous glands; consists mainly of fat, keratin and other cellular material.

Secondary Intention – The process of healing that includes coagulation and inflammation reepithelialisation, granulation tissue formation, angiogenesis and collagen remodelling.

Selenium – A chemical agent resembling sulphur that helps protect the skin from solar induced skin cancers.

Sodium Lauryl Isethionate – Similar to Sodium Lauryl Sulphate but not as irritating. It is less effective as an emulsifier.

Sodium Lauryl Suplhate – A common ingredient in household detergents and soaps most commonly used as an emulsifier.

Squamous Cell Carcinoma – A malignant cancer of the epithelial cells.

Static Rhytids – Wrinkles that show without reference to movement.

Stratum Basal – The lowest layer of the epidermis. This layer houses the germinal cells and regenerating cells for all layers of the epidermis.

Stratum Corneum – The superficial sublayer of the epidermis; this layer varies in thickness throughout the body.

Subcutaneous – Beneath the skin.

Superficial Peels – a peel depth that extends into the stratum granulosum.

Surfactants – A surface active agent that lowers surface tension.

Tartaric Acid – An AHA derived from grapes.

Telangiectasia – Dilation of a group of small blood vessels.

Titanium Dioxide – Physical sunscreen that scatters light rather than absorbing or filtering it.

Transepidermal Water Loss – The process by which our bodies constantly lose water via evaporation.

Trichloroacetic Acid – Chemical used in peel solutions that dissolves ageing cells to make room for newer healthier cells.

Ubiquinone – Lipid soluble cellular antioxidant present in virtually all cells.

Vasoconstriction – Narrowing of the blood vessels.

Vesiculation – The process of forming blisters.

Vitamin B – Vitamin B is a complex of several water soluble nutrients. Each nutrient is numbered and each has a specific function.

Vitamin C – Vitamin C is an antioxidant that is a necessary factor for the formation of collagen in connective tissue and maintenance of integrity of intercellular cement.

Vitamin E – Vitamin E is an antioxidant that has been show to inactivate free radicals, although the exact mechanism of function is unknown.

Vitiligo – Smooth, depigmented white spots on the skin.

Wound – A disruption of normal tissue that results from pathologic processes, beginning internally or externally to the involved organ.

Wound Healing – The restoration of tissue continuity following injury or trauma.

Zinc Oxide – Physical sunscreen the scatters light rather than absorbing or filtering it.