Definition , structure of skin relating to dry skin, acne, pigmentation PDF/PPT

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Definition , structure of skin

relating to dry skin, acne,




Cosmetic means any article intended to be rubbed, poured, sprinkled or sprayed
on, or introduced into, or otherwise applied to, the human body or any part thereof
for cleansing, beautifying, promoting attractiveness, or altering the appearance and
includes any article intended for use as a component of cosmetic.

Definition of “Cosmetic Products”

The European Union Cosmetics Directive defines a cosmetic as “any substance
or preparation intended to be placed in contact with the various
external parts of the human body (epidermis, hair system, nails, lips
and external genital organs) or with the teeth and the mucous
membranes of the oral cavity with a view exclusively or mainly to
cleaning them, perfuming them, changing their appearance and/or
correcting body odors and/or protecting them or keeping them in good



A cosmetic is deemed to be misbranded –
• If it contains colour which is not prescribed, or
• If it is not labelled in prescribed manner, or
• If the label or container of anything accompanying the cosmetic bears any

statement which is false or misleading in particular.

[Cosmeceuticals- Cosmetic product with pharmaceutical grade ingredients]


A cosmetic is deemed to be spurious-
• If it is imported under a name which belongs to another cosmetic, or
• If it is an imitation of, or a substitute for, or resembles another cosmetic
• If the label of the container bears the name of an individual or company

purporting to be the manufacturer of the cosmetic, which individual or
company is fictitious and does not exist, or

• If it purports to be the product of a manufacturer of whom it is not truly a



Structure of Skin



Skin has three distinct layers, namely the outermost epidermis, the dermis and
hypodermis or subcutaneous layer.
(a) Epidermis:
The epidermis is made up of many layers of cells.
▪ Outermost layer of the skin, composed of stratified squamous epithelial cells
▪ Microscopic sections of epidermis shows 2 main parts:
a) The stratum corneum( Horny layer)
b) The stratum Germinativum ( Viable epidermis)

➢ Process of differentiation is by mitosis resulting in migration of cells from basal
layer towards skin surface.

➢ The epidermis varies in thickness from 75 to 150 micrometers in most areas. And
up to 4mm in palms of the hands and soles of the feet.

Stratum corneum: It forms outermost layer of epidermis ( 10-15 micrometre).
It is quite dry and consists primarily of blocks of cytoplasmic protein matrices
(keratin) embedded in the extracellular lipid.
The keratin containing cells known as corneocytes, have an interlocking arrangement.
Stratum Germinativum: It is the generative layer of epidermis. Contains basal cells.



(b) The dermis:
The dermis is the layer of skin beneath the epidermis that consists of
epithelial tissue .The dermis is tightly connected to the epidermis by a
basement membrane.

It also harbors many nerve endings that provide the sense of touch and
heat. It contains the hair follicles, sweat glands, sebaceous glands, apocrine
glands, lymphatic vessels and blood vessels.

The blood vessels in the dermis provide nourishment and waste removal
from its own cells as well as from the Stratum basale of the epidermis.

Dermis consists of:
Collagen and elastin: collagen forms the major constituents of the fibrous
proteins which gives the skin its tensile strength.
Elastin; makes up a smaller percentage and tends to be interwoven among
the collagen bundles. These elastin fibers allow the skin to deform and
return to its original state once the pressure or tension is removed.



Ground substance: Consists of salt, water and glycosaminoglycans. It
forms complex with protein molecules known as proteoglycans.
Mast cells: Second major cell type in the dermis, can be found close to the
small blood vessels. They are responsible for the synthesis and secretion
of heparin (anticoagulant), histamine and prostaglandins, both are
vasoactive substance.

(c) Hypodermis or Subcutaneous Tissue:
• The hypodermis or subcutaneous fat tissue supports the dermis and

epidermis. It serves as a fat storage area.
• This layer helps to regulate temperature, provides nutritional support

and mechanic protection.
• It carries principal blood vessels and nerves to skin and may contain

sensory pressure organs.
• The subcutaneous layer is quite elastic.



Problems related to the skin

I. Dry skin

II. Acne

III. Pigmentation

IV. Prickly heat

V. Wrinkles and

VI. Body odor.



(1) DRY SKIN: Dry skin is an awkward condition set apart by
scaling, tingling, and breaking.
Dry skin is a condition described as absence of water in the
most shallow layer of the skin.
• Dry skin has a low level of sebum and can be prone to sensitivity.
• It usually feels “tight“ and uncomfortable after washing unless some type

of moisturizer or skin cream is applied.
• Chapping and cracking are signs of extremely dry, dehydrated skin.
• It looks dull, especially on the cheeks and around the eyes. There may be

tiny expression lines on these spots and at the corners of the mouth



• The oil glands do not supply enough lubrication to the skin. As a result, the

skin becomes dehydrated.
• Dry skin could be due to a genetic condition.
• Poor diet. Nutritional deficiencies, especially deficiencies of vitamin A and

the B vitamins, can also contribute to dry skin.
• Environmental factors such as exposure to sun, wind, cold, chemicals, or

cosmetics, or excessive bathing with harsh soaps.
• Conditions such as dermatitis, eczema, psoriasis.

Ichthyosis Vulgaris
Allergic Eczema
Primary Hypothyroidism
Heat Emergencies




Xeroderma or xerodermia “dry skin”, is a condition which can safely be treated
with emollients or moisturizers.

Cleansing, Moisturizing
Change in lifestyle
Humidify during winter
Applying cool cloths
Avoiding heat

1)Cleansing :-
•Apply moisturizers and or emollients while the skin is still moist;
apply liberally once a day at a minimum and reapply when required.
•A barrier cream may be useful for hands and feet.
•When scaling is present, consider a keratolytic such as a urea-based
moisturizer, salicylic acid, lactic acid, or glycolic acid for mildly,
moderately, and severely dry skin.
Consider a higher concentration keratolytic product on hands and feet.



2) Skin Care Products



Dry skin needs plenty of thorough but gentle cleansing, regular stimulation with
massage and generous quantities of oil and moisture.
Washing dry skin with soap and water not only removes grime but also the
natural oils protecting the skin.
A moisturizer increases the water content of the outer layers of the skin and gives
it a soft, moist look.

Eat a balanced diet that includes vegetables, fruits, grains, seeds, and nuts.
Drink at least 2 L of water every day to keep the skin well hydrated. Eat foods
such as garlic, onions, eggs, and asparagus that are high in sulfur, which helps to
keep the skin smooth and youthful.



(2) ACNE:
Acne, also known as acne vulgaris
Its an inflammatory skin condition that occurs when oil and dead skin cells
block the pore opening, causing sebum (oil) to build up inside the pore.

It is characterized by blackheads or whiteheads, pimples, oily skin,
and possible scarring.
• It primarily affects areas of the skin with a relatively high number
of oil glands



• Stage 1: Clogged Pores. Cells lining

pores shed and mix with excess sebum
produced by sebaceous glands,
forming a plug, which leads to clogged

• Stage 2: Bacteria. Accumulated
sebum and dead cells attract propioni
bacterium naturally found in skin,
which feeds on oil and multiplies
rapidly inside pores.

• Stage 3: Inflammation. This
bacterial overgrowth triggers the
natural inflammatory response
causing swelling and redness. This can
ultimately lead to discoloration and



• Genes
• Hormonal activity, such as occurs during menstrual cycles and puberty
• Infections against anaerobic bacterial species Propionibacterium acnes
• High-glycemic-load diets
• Stress can aggravate the skin by triggering release of androgens and cortisol.

These stress hormones can stimulate an overproduction of oil. When this excess
oil mixes with dead skin cells, it promotes bacterial growth and can cause acne
to develop or worsen.

• Acne is caused by the excess production of sebum from skin.
• Several medications like lithium, hydantoin, isoniazid, glucocorticoids, iodides,

bromides, and testosterone.




➢ Too much washing will only irritate the skin further and worsen their acne.
Gently washing the face daily with mild cleanser or soap, pat dry and use
appropriate acne treatment.

➢ Antibiotics used for mild to moderate inflammatory acne.
• They have activity against P. acnes, act on the surface of the skin to reduce the

stimulus for inflammation of the lesions, inhibit the growth of bacteria and
reduce inflammation. Topical antibiotics used in acne treatment are
erythromycin, clindamycin etc.

➢ Benzoyl Peroxide
•Benzoyl peroxide is a topical disinfectant, originally employed as a peeling agent
for treating acne .
•Benzoyl peroxide has proven bactericidal activity against P. acnes by releasing
free radical oxygen, which degrades the bacterial proteins

➢ Azelaic Acid
•Azelaic acid is a natural dicarboxylic acid that inhibits protein synthesis of the P.
acnes species .
•It is an effective agent because it has bacteriostatic, anti-inflammatory,



➢ Use anti-androgen (e.g. oral contraceptive pills) to regulate androgen, to prevent
excess sebum production. This method is only suitable for women.

➢ Some acne scar will remain permanent, so patients should use appropriate acne
treatment as soon as possible.

Help clear dead skin
Help clear blackheads
This allows sebum to move freely again
The spots heal




Skin color is due to a pigment, called melanin. Melanin is produced by melanocytes

( cells present in the basal layer of the epidermis) and is responsible for the

coloration of skin, hair and eyes.

• Melanin is synthesized by melanocytes within melanosomes and transferred to


Pigmentation disorders are disturbances of human skin color, either loss or

reduction, which may be related to

➢ loss of melanocytes or the

➢ inability of melanocytes to produce melanin or

➢ transport melanosomes correctly.

•Pigmentation is the coloring of an individual’s skin. The color of skin appears

normal when a person is healthy.

• A person’s skin may change color and grow darker (hyperpigmentation) or lighter

(hypopigmentation) because of illness and/ injury.





Two types:
(a) Hyperpigmentation:
• This is the disorder due to abnormal pigmentation which occurs on a smack

area of the skin, due to an increased local synthesis of melanin in epidermis.
• This can be further stimulated by exposure to UV or X-ray irradiation.


• Old bleaching agents
➢ Hydroquinone (tyrosin inhibitor)
➢ Corticoïds

• Associated with « peeling » / dermabrasion products
➢ Vitamin A
➢ Glycolic acid

• Best treatment: Kligman trio
➢ Corticoïds(dexamethasone)
➢ Hydroquinone
➢ Retinoic acid



Synthesis of lesser amount of melanin in part of skin can cause
hypopigmentation, which is called vitiligo, i.e patchy depigmentation of
the skin.
A decrease or total absence of melanocytes in the depigmented areas
has been observed.


UV narrow band
• For 10 years: unknown risk cancer
Topical treatments
• Tacrolimus
• Cortic

Definition , structure of skin

relating to dry skin, acne,

Surgery: too invasive technique
• If spot entirely healed, no relapsing