Topical Skin Care and Baumann Skin Typing

Comprehensive vocabulary flashcards covering the Baumann Skin Typing System, skin hydration mechanisms, moisturizer types, sensitivity categories, pigmentation pathways, and aging processes as described in the lecture notes.

Helena Rubinstein

The cosmetics entrepreneur who identify four basic skin types in the early 1900s: dry, oily, combination, and sensitive.

Cosmeceuticals

Cosmetic products that may confer some biological function in the skin.

Baumann Skin Typing System (BSTS)

A classification system based on four parameters (dry or oily; sensitive or resistant; pigmented or nonpigmented; and wrinkled or unwrinkled) yielding 16 potential skin-type permutations.

Xerosis

The medical term for dry skin, characterized by dull color, rough texture, and an increased amount of ridges.

Stratum Corneum (SC)

The outermost layer of the skin, often described as a 'bricks and mortar' structure where keratinocytes are the bricks and lipid bilayers are the mortar.

Transepidermal Water Loss (TEWL)

The process where water escapes from the stratum corneum, which is prevented by the lipid bilayer when it is intact.

Natural Moisturizing Factor (NMF)

An intracellular, hygroscopic compound released by lamellar bodies in the upper levels of the stratum corneum that potently binds to water molecules.

Filaggrin

A protein that confers structural support and strength to lower SC layers and is broken down into free amino acids to form Natural Moisturizing Factor (NMF).

Aquaporin-3 (AQP3)

A member of the aquaglyceroporins family located in the plasma membrane of human epidermal keratinocytes that facilitates the transport of water, glycerol, and urea.

Ajuga turkestanica

The only herb extract mentioned that has been shown to enhance the activity of Aquaporin-3 ($AQP3$).

Sebum

Oily secretion from sebaceous glands containing wax esters, sterol esters, cholesterol, di- and triglycerides, and squalene.

Occlusives

Oily compounds that coat the stratum corneum to impede TEWL, such as petrolatum, paraffin, and mineral oil.

Humectants

Water-soluble and hygroscopic compounds that attract water from the atmosphere and underlying skin layers, such as glycerin, urea, and sodium hyaluronate.

Emollients

Substances primarily composed of lipids and oils that hydrate and smooth the skin by filling gaps between desquamating corneocytes.

Glycerin

A potent humectant with a hygroscopic capacity similar to NMF that expands the stratum corneum by augmenting corneocyte thickness.

Alpha Hydroxy Acids (AHAs)

Naturally occurring organic acids like glycolic acid and lactic acid that function as both humectants and exfoliants.

Salicylic acid

The lone beta hydroxy acid ($BHA$) which acts as a chemical exfoliant but does not have humectant properties.

Propionibacterium acnes

The bacteria that migrates into hair follicles and triggers an inflammatory response in the development of acne.

Rosacea

An acneiform condition in adults characterized by facial redness, flushing, papules, and the development of prominent telangiectases.

Lactic acid stinging test

A widely accepted approach for identifying 'stingers' or individuals with nonallergic neural sensitivity.

Melanocytes

Cells that produce melanin (skin pigment) and transfer it via melanosomes to keratinocytes.

Tyrosinase

An enzyme that breaks down tyrosine into DOPA and then dopaquinone to yield melanin.

Protease-activated receptor (PAR)-2

A seven transmembrane G-protein coupled receptor in keratinocytes that, when activated, triggers the engulfment of melanosomes.

Telomeres

Specialized structures that protect the ends of chromosomes and whose shortening is considered a gauge of intrinsic aging.

Extrinsic aging

The preventable premature aging of the skin caused by exogenous factors like smoking, poor nutrition, and solar exposure.

Matrix metalloproteinases

Enzymes such as collagenase and stromelysin that are triggered by UV exposure and attack the collagen and connective tissue of the skin.