The later structure of the epidermis is the morphological expression of the stepwise differentiation andmaturation process towards cell keratinization. In the stratum spinosum and stratum granulosum inter-cellular processes lead to the formation of the stratum corneum.




Furrows, wrinkles, lines, ridges, plains: in the course of life increasing amounts of furrows andwrinkles are formed in what started as smooth child’s skin. Furrows are wrinkles caused bymoving appear at the joints. Age-related wrinkles and furrows appear as signs of the aging ofthe skin or the linked emotions on account of the mimetic facial musculature (laughter lines,frown lines). The Skin surface is covered by a complex hydrolipidic film (skin surface film). It consists primarilyof secretions from sweat glands and sebaceous glands and houses the physiologicalflora of the skin.

Skin color (also complexion) is an individual characteristic that is determined above all by the pigmentation of the skin and the structure of the blood vessels. Various pigments have an effect on the color ofthe skin. The quantity of melanin is a particular decisive factor in humans. The color of the skin, whether fair, medium or dark, depends in part on the blood supply to the skin, and primarily on the melanin,or coloring matter, which is deposited in the stratum germinativum and the papillary layers of the dermis. The pigment’s color varies in different people. The distinctive color of the skin is a hereditary traitand varies among races and nationalities.The amount of melanin in the skin is genetically determined, but more melanin is also produced underexposure to sunlight (ultraviolet rays) within a certain wavelength. There are two types of melanin: oneis eumelanin a brown-to-black pigment, and the other is pheomelanin, a red-to-yellow pigment.Eumelanin determines the skin type and with this the skin color. Pheomelanin then produces, especially in people with light skin types, a reddish or yellowish undertone. Red hair is a clear indicator thatmuch more pheomelanin than eumelanin is being produced. This is why the extremely Light Skin TypeI is mainly associated with red hair.


  • Protection

  • Sensation

  • Heat Regulation

  • Exertion

  • Secretion

  • Absorption


Through its sensory nerve endings, the skin responds to heat, cold, touch, pressureand pain. Extreme stimulation of sensory nerve endings produces pain. A minor burn is verypainful, but a deep burn that destroys nerves may be painless. Sensory endings, responsive totouch and pressure, are situated near hair follicles.


Through its sensory nerve endings, the skin responds to heat, cold, touch, pressureand pain. Extreme stimulation of sensory nerve endings produces pain. A minor burn is verypainful, but a deep burn that destroys nerves may be painless. Sensory endings, responsive totouch and pressure, are situated near hair follicles.


The healthy body maintains a constant internal temperature of about 98.6degrees Fahrenheit (37 degrees Celsius). As changes occur in the outside temperature,the blood and sweat glands of the skin make necessary adjustments in their functions.Heat regulation is a function of the skin, the organ that protects the body from the environment.The body is cooled by the evaporation of sweat.


Perspiration from the sweat glands is excreted from the skin. Water lost by perspirationcarries salt and other chemicals with it.


Sebum is secreted by the sebaceous glands. Excessive flow of oil form the oil glandsmay produce seborrhea. Emotional stress may increase the flow of sebum.


This function is limited, but it does occur. Female hormones, when an ingredient of a face cream, may enter the body through the skin and influence it to a minor degree. Fatty materials, such as lanolin cream, are absorbed largely through the hair follicles andsebaceous gland openings.



Melanocytes are the pigment-producing cells of the skin and are located in the basal cell layer of theepidermis and in the hair follicles.They synthesis melanin and pass these in the form of what are called melanosomes to the surroundingkeratinocytes. Melanin delivers important skin protection against ultraviolet rays. Melanin-producingcells together with the surrounding keratinocytes form what is called a melanocyte unit.Skin color is not determined by an increase in the quantity of melanocytes, rather to a much greaterdegree by how long melanosomes remain in the keratinocytes.

1. Hair: protects against heat loss and the rays of the sun.

2. Horny Layer: protects against injury and dehydration. 

3. Melanocytes: protect the genetic information in cell nuclei against UV radiation.

4. Free Nerve Endings: reception of tactile stimuli and sensations of pain.

5. Lamellar Corpuscles: reception of pressure stimuli.

6. Sweat Glands: production of sweat, through evaporation protects against overheating.

7. Cold Receptors: reception and cold stimuli. 

9. Heat Receptors: reception of heat stimuli.

10. Hair Follicle Muscle: thermal insulation through causing the vellus hairs to stand erect. 

11. Sebaceous Gland: production of sebum (fat)

12. Tactile Corpuscles: reception of tactile stimuli.

13. Fatty Deposits: protection against pressure and heat loss.

14. Blood Vessels: temperature regulation and provision of nutrients and oxygen to the cells


The skin is a surface organ (not a compact organ) that covers and protects the outside of the organism(it is an “integument”). The cutis consists of the epidermis and dermis. Its total area is around 1.5 to 2m(adult), and it is between around 1 and 4mm thick (excluding the subcutis). The outer skin transformsinto the mucous membrane of the body’s inner surface at the body orifices.

It is very important for technician to have a thorough understanding of the skin to be successful in thisindustry. Adequate time must be devoted to learning the anatomy of the skin. New information is constantly being released about the effects of pigment implanted within the skin. It is important to keep upto date with this information.The skin is the largest and one of the most important organs of the body. A healthy skin is slightlymoist, soft and flexible, possesses a slightly acid reaction, and is free from any disease or disorder. Itstexture (feel and appearance) ideally is smooth and fine grained. A good complexion is an indication ofthe fine texture and healthy color of the skinThe skin varies in thickness, being thinnest on the eyelids and thickest on the palms and soles. Con-tinued pressure over any part of the skin may cause it to thicken and develop into a callous. The skinof the scalp is constructed similarly to the skin elsewhere on the human body. However, the scalp haslarger and deeper hair follicles to accommodate the longer hair of the head.

  • Epidermis

  • Dermis or corium

  • Subcutis or hypodermis


  • Stratum corneum or horny layers

  • Stratum lucidum or clear layer

  • Stratum granulosum or granular cell layer

  • Stratum spinosum or spinous layer

  • Stratum basale or basal cell layer


The stratum corneum, or horny layer, is theouter fayer of the skin. Its scale-like cells arecontinually being shed and replaced byunderlying cells coming to the surface. Thesecells contain keratin, a protein substance. Theoverlapping cells are covered by a thin layerof oil which helps make the stratum corneumalmost waterproof.


The stratum lucidum, or clear layer, consists ofsmall transparent cells through which light canbe passed.


The stratum granulosum, or granular fayer,consists of cells that look like distinct granules.These cells are almost dead and undergoa change into a horny substance.


The stratum germinativum, formerly known asthe stratum mucosum and basal layer andMalpighian layer, is composed of several layersof differently shaped cells. The deepest layer is responsible for the growth of theepidermis. It also contains a dark skin pigment called melanin, which protects the sensitivecells below from the destructive effects of excessive ultra-violet rays of the sun or of anultra-violet lamp.


The dermis is the true skin. It is a highly sensitive and vascular layer of connective tissue. Within itsstructure are found numerous blood vessels, lymph vessels, nerves, sweat glands, oil glands, hair follicles, arrector pili muscles and papillae. The dermis consists of two layers: the papillary, or superficiallayer, and the reticular, or deeper layer.

The papillary layer lies directly beneath the epidermis. It contains small cone-shaped projectionsof elastic tissue that point upward into the epidermis. These projections are called papillae. Some of these papillae contain looped capillaries; others contain nerve fiber endings,called tactile corpuscles. This layer also contains some of the melanin skin pigment. 

Subcutaneous tissue is a fatty layer found below the dermis. This tissue is also called adipose or sub-cutis tissue and varies in thickness according to the age, sex and general health of the individual. Itgives smoothness and contour to the body, contains fats for use as energy, and also acts as a protec-tive cushion for the outer skin. Circulation is maintained by a network of arteries and lymphatics.


A lesion is a structural change in the tissues caused by injury or disease. There are three types:

  • Primary

  • Secondary

  • Tertiary

The intradermal cosmetic technician is concerned with primary and secondary lesions only. Knowingthe principal skin lesions helps the intradermal cosmetic technician to distinguish between conditionsthat may or may not be treated in the clinic setting.A symptom is a sign of disease. The symptoms in diseases of the skin are divided into two groups:

1. Subjective refers to symptoms that can be felt, as itching, burning or pain. 

2. Objective refers to symptoms that can be seen, as pimples, pustules or inflammation.


a blister containing a watery fluid, similar to a vesicle, but larger.


a small, discolored spot or patch on the surface of the skin, neither raised nor sunken, asfreckles.


a small, elevated pimple in the skin, containing no fluid but which may develop pus.


an elevation of the skin having an inflamed base, containing pus.


a solid lump larger than a papule. It projects above the surface or lies within or under theskin.


an external swelling, varying in size, shape and color.


a blister with clear fluid in it. Vesicles lie within or just beneath the epidermis. (Ex: Poison Ivy)


an itchy, swollen lesion that lasts only a few hours. (Ex: Hives)


Crust, Excoriation, Fissure, Scale, Scar (Cicatrix), Stain, Ulcer, Disease, Acute Disease, Chronic Disease, Contagious Disease, Infectious Disease, Skin Disease, Allergy, Congential, Epidemic, Inflammation, Occupational Disease (such as Dermatitis), Parasitic Disease, Seasonal Disease, Systemic Disease, Venereal Disease. 


There are several common disorders of the sebaceous (oil) glands which the intradermal cosmetictechnician should be able to identify and understand. The disorders are listed below:

COMEDONES - or blackheads, are worm-like masses of hardened sebum, appearing most frequentlyon the face, forehead and nose. Blackheads accompanied by pimples often occur in youths between the ages of 13 and 20. During theadolescent period, the activity of the sebaceous glands is stimulated, thereby contributing to the formation of blackheads and pimples.

MILIA, or whiteheads, is a disorder of the sebaceous (oil) glands caused by the accumulation of thesebaceous matter beneath the skin. This may occur on any part of the face, neck and, occasionally, onthe chest and shoulders. Whiteheads are associated with fine-textured, dry types of skin.

ACNE is a chronic inflammatory disorder of the sebaceous glands, occurring most frequently on theface, back and chest. The cause of acne is generally held to be microbic, but predisposing factors areadolescence and disturbance of the digestive tract. Acne, or common pimples, is also known as acnesimplex or acne vulgaris.Acne appears in a variety of different types, ranging from the simple (non-contagious) pimple, to serious, deep-seated skin conditions. It is always advisable to have the condition examined and diagnosedby a physician before any service is given.

SEBORRHEA is a skin condition caused by an excessive secretion of the sebaceous glands. An oily orshiny condition of the nose, forehead, or scalp indicates the presence of seborrhea. On the scalp, it isreadily detected by the unusual amount of oil on the hair.

STEATOSIS - is a condition of dry, scaly skin, characterized by absolute or partial deficiency of the sebum, due to senile changes (old age) or some bodily disorders. In local conditions, it may be caused byalkalis, such as those found in soaps and washing powders.

ROSACES, formerly called acne rosacea, is a chronic inflammatory congestion of the cheeks and nose.It is characterized by redness, dilation of blood vessels, and the formulation of papules and pustules. Itis usually caused by poor digestion and over-indulgence in alcoholic beverages.

ROSACES, formerly called acne rosacea, is a chronic inflammatory congestion of the cheeks and nose.It is characterized by redness, dilation of blood vessels, and the formulation of papules and pustules. Itis usually caused by poor digestion and over-indulgence in alcoholic beverages.

STAINS - abnormal brown skin patches, having a circular and irregular shape. Their permanent color isdue to the presence of blood pigment. They occur during aging, after certain diseases, and after disap-pearance of moles, freckles and liver spots. The cause of these stains is unknown.

CHLOASMA - characterized by increased deposits of pigment in the skin. It is found mainly on the forehead, nose and cheeks. Chloasma is also called moth patches or liver spots.

NAEVUS - commonly known as birthmark. It is a small or large ma/formation of the skin due to pigmentation or dilated capillaries.

LEUCODERMA - abnormal white patches in the skin, due to congenital defective pigmentation.

VITILIGO - an acquired condition of the leucoderma, affecting the skin or the hair. The only treatment ismatching cosmetic color, making it less conspicuous.

ALBINISM - congenital absence of melanin pigment in the body, including the skin, hair and eyes. Thesilky hair is white. The skin is pinkish white and will not tan.




Keratoma, or callous, is an acquired, superficial, round, thickened patch of epidermis, due to pressure friction on the hands and feet. If thickening grows inward, it is called a corn.


Moles are small, brownish spot, or blemish on the skin. Miles are believed to be inherited. They range incolor from pale tan to brown or bluish black. Some moles are small and flat, resembling freckles, whileothers are more deeply seated and darker in color. Large, dark hairs often occur in moles. Any changein a mole requires medical attention. CAUTION: Do not treat or remove hair from moles.


The verruca is the technical term for wart. It is caused by a virus and is infectious. It can spread from one location to another, particularly along a scratch in the skin.


This a disorder causing baldness in spots. This condition may be treated under thedirection of a physician. Alopecia refers to a condition of premature baldness or excessive hair loss.The chief causes of alopecia are poor circulation, lack of proper stimulation, improper nourishment,certain infectious skin diseases, such as ringworm, or constitutional disorders. The treatment of alopecia is directed to stimulating the blood supply to the scalp and reviving the hair papillae involved in hairgrowth.



This information has been compiled to help the intradermal cosmetic technician become familiar withcertain common skin disorders with which they may come into contact. Any client with a skin conditionthat the technician does not recognize to be a simple disorder should be referred to a physician. Themost important thing to know is that a client who has an inflammatory skin disorder, which may or maynot be infectious, should be treated. Listed below are a number of important terms with which the intradermal cosmetic technician shouldbe familiar.


the study of the skin, its nature, structure, functions, disease and treatment.


A skin specialist.


the recognition of a disease by its symptoms.


the study of the causes of disease.


the study of disease.


the foretelling of the probable course of the disease.


the study of hair and its diseases.


Contact Gaby on WhatsApp 

at+1 (626) 376-5269