The document discusses the structure of skin relating to conditions like dry skin, acne, and pigmentation. It begins with an overview of basic skin histology, describing the two main regions of the epidermis and dermis. It then provides more detail on the layers, cells, and functions of the epidermis and dermis. The document also discusses dry skin, its causes and treatments. For acne, it covers causes like genetics and bacteria, as well as common treatment options. Finally, it briefly introduces skin pigmentation and some related terminology starting with "mela."

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Structure of skin relating to problem like dry skin, acne , pigmentation
RR COLLEGE OF PHARMACY
SUBMITTED BY: SUBMITTED TO:
PAWAN DHAMALA ASST. PROF. SRILATHA.K.S
2nd SEM , M.PHARMACY
DEPARTMENT OF PHARMACEUTICS

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• Structure of skin
• Dry skin
• Acne
• Skin pigmentation

3. STRUCTURE OF SKIN
Basic Skin Histology
• The skin is considered the largest organ of the body and has many
different functions.
• The skin is divided into two main regions, the epidermis, and the
dermis.
• The dermis is attached to an underlying hypodermis, also called
subcutaneous connective tissue.
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4. Functions of skin
1. Protective function : It is the first line of defense. It protects our body from infection,
pathogens, and harmful UV irradiation.
2. Sensory function: Free nerve endings on the skin are sensitive to pain, touch, heat and cold,
resulting in either voluntary or reflex activities.
3. Secretory function: Sweat help in temperature regulation and sebum makes skin smooth.
4. Heat regulatory function: Sweating and cutaneous blood flow help in temperature
regulation.
5. Excretory function: Through the secretion of glands of the skin – water, salt, fatty substances
and urea are excreted.
6. Synthetic function : Sun’s ultraviolet rays help in synthesis of natural vitamin D. Skin can
also manufacture melanin pigment.
7. Water balance: Skin serve a useful means in regulating water balance of the body by
perspiration.
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5. What is contained in an inch of the skin?
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 Millions of cells (9,500,000)
 Intricate network of blood vessels (19
yards)
 Nerves (78 yards)
 Pores for Sebaceous glands (95 -
100)
 Pores for Sweat glands (650)
 65 hairs
 Nerve endings to record pain (1,300)
 Sensory cells at the end of nerve
fibers (19,500)
 Sensory apparatuses for heat (78)
 Sensory apparatuses for cold (13)
 Pressure Apparatuses (160 – 165)

6. Divisions of the Skin
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7. Epidermis – cuticle or scarf skin
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 Epidermis protects the delicate tissues of the body from injury.
 Epidermis is made of soft keratin, a protein which is found in the epidermis as dry
scales.
 Outermost layer of the skin; sheds daily with completely new cuticle layer by
28th day; tightly packed, scale like cells; turnover slows with age.
 Contains no blood vessels, but contains many small nerve endings.
 Dispute over how many layers in epidermis, between 4 – 6.
 Bottoms layers are sometimes classified together, known as the basal layer.

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1.Stratum corneum: is a dead horny layer; tightly packed, scale like cells
containing keratin surrounded by lipids, continuously shed & replaced.
2. Stratum lucidum: dead clear layer, transparent cells through which light can
pass (onlyon hands and feet; not present where there are hair follicles).
3. Stratum granulosum: granular layer; cells that look like distinct granuals; these
cells aredying
4. Stratum spinosum: prickle cell layer; as cells undergo mitosis below, they are
pushed upward into this layer; begins basal layer.
5. Stratum basale: basal layer - also called stratum germinativum, which refers to
lowest row of cells to make up basal layer (living stratum).
Stratum Germinativum: composed of single layer of cells, lowest layers of cells to
make up basal layer; mitosis happens here and cells begin journey to surface, to
replace older cells that sheds; approximately 28 days for journey; pigment granules
produced here (melanocytes) to give skin color.

9. • Keratinocytes
About 90% of the cells in the epidermis are keratinocytes, which produces a tough,
fibrous protein called keratin. This protein is the main structural protein of the
epidermis, and it provides many of the skin’s protective properties.
The old keratinocytes at the upper surface of the skin constantly sheds off.
Meanwhile, cells in the lower layers of the epidermis divide continually, producing new
keratinocytes to replace those that sheds off.
By the time the cells reach the uppermost layer of the epidermis, they are dead and
completely filled with the tough protein.
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Epidermis
Keratinocytes , Melanocytes, Langerhans Cells, Merkel Cells

10. • Melanocytes
Scattered among the keratinocytes in the epidermis are melanocytes, cells that produce a
dark pigment called melanin. This pigment gives color to the skin and protects it from the
sun’s ultraviolet rays.
Differences in skin color result from differences in the amount of melanin produced and
how melanosomes which are packets of melanin, arranged in the keratinocytes.
A type of melanin called pheomelanin makes red headed people more sensitive to the sun.
A total lack of melanin, a genetic condition called albinism, makes people extremely
sensitive to the sun. People with albinism have very light skin, hair, and eyes.
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11. • Langerhans cells
The epidermis also contains a type of immune cell known as a Langerhans cell.
Produced in the bone marrow, langerhans cells take up sentry like positions in the
epidermis, where they help cells of the immune system recognize potentially
dangerous microorganisms and chemicals.
• Merkel cells
Another cell in the epidermis is the Merkel cell, found in sensitive, hairless areas
such as the fingertips and lips.
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12. Located in the deepest layer of the epidermis, merkel cells contact nerve endings in the
dermis below, and function as a type of touch receptor.
• Dermis – derma or true skin
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 Made of collagen and elastin (protein fibers); gives skin
strength, form, flexibility
 Dermis contains blood vessels, fat cells, oil and sweat
glands held together by collagen
 Dermis is the thickest layer of connective tissue; binds
epidermis to subcutaneous tissue
 Network of nerves, blood and lymph vessels provide
nutrition to itself and epidermis.

13. • Dermis – 2 layers
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1. Papillary Layer: superficial layer
 The upper part of the dermis is known as the papillary layer. It is characterized by
dermal papillae, which are small, cone shaped projections of elastic tissue that point
upward, containing nerve fiber endings for sense of touch. In the thick skin on the
palms and toes, the epidermis conforms to the shape of the underlying dermal papillae,
forming ridges and valleys that we know as fingerprints. These ridges provide traction
that helps people grasp objects and surfaces.

14. Some dermal papillae contain touch receptors called Meissner’s corpuscles, and
many contain loops of tiny blood vessels. The extensive network of blood vessels
in the dermal papillae plays an important role in the regulation of body
temperature. The blood vessels dilate in hot environments to help dissipate heat,
and they constrict to conserve heat in cold environments.
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2. Reticular Layer: deeper layer
The lower layer of the dermis is called the reticular layer. It is made of mainly coarse
collagen and elastic fibers. Skin appendages such as glands and hair follicles are often
anchored in the reticular layer of the dermis.
The reticular layer also contains several different types of sensory receptors, nerve cells
specialized to detect various stimuli.

15. • Collagen
The main structural component of the dermis is a protein called collagen. Bundles of collagen
molecules pack together throughout the dermis, accounting for three-fourths of the dry weight
of skin. Collagen is also responsible for the skin’s strength.
• Elastin
Another protein in the dermis, elastin, is the main component of elastic fibers. These protein
bundles give skin its elasticity. Collagen and elastin are produced by cells called fibroblasts,
which are found scattered throughout the dermis.
• Subcutaneous Tissue
 Fatty layer; attaches dermis to underlying structures.
 Composed of adipose and connective tissue.
 Serve as shock absorbers for vital organs, stores energy.
 Varies in thickness according to age, sex, general health of individual.
 Gives smoothness, shape to body, contains fats for use as energy, heat insulator.
 Circulation is maintained by network of arteries, and lymphatics (removes bacteria
and foreign materials, produces antibodies to fight infection).
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16. DRY SKIN
Dry skin, also called xerosis, is a very common skin condition that occurs at all
ages. Usually, it doesn't represent a serious problem but sometimes it can be
difficult to treat. Moreover, it might be correlated to other skin diseases or
associated to pathological conditions such as diabetes, hypothyroidism and
hyperthyroidism, Sjögren syndrome, malnutrition.
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17. • Dry air (low humidity), probably the most common cause of dry skin, causes an
evident reduction of water content.
• Furthermore, dry skin results when lipids are depleted and there is not enough
water in the stratum corneum for it to function properly. Atopic dermatitis, a
common dry skin condition in childhood, shows reduced lipids levels in the
stratum corneum and, consequently, an important loss of water.
• Severe dry skin is a feature of the inherited group of disorders called ichthyosis:
the most common form of ichthyosis is defined ichthyosis vulgaris, characterized
by fine scaling that is most prominent over the legs and usually presents within the
first few months of life.
• Furthermore, xerosis may represent a symptom in other skin diseases such as
asteatotic eczema, lichen and psoriasis.
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19. What causes dry skin?
Simple causes of lipids depletion include harsh soap, itchy clothing,
long and hot showers or baths.
An important environmental factor is represented by the exposure to hot
or cold weather with low humidity levels.
Xerosis often worsens in the winter, when several factors contribute to
skin dryness: low temperature and low humidity associated to very hot
and drying heating, cause a decreased amounts of water in the stratum
corneum.
 During summer, constant exposure to air conditioning may produce
similar effects.
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20. Treatment and prevention
These are easy suggestions that are important to keep in mind:
•Choose short showers over baths. Long baths or showers, especially in hot water,
increase the loss of natural oils from the skin and worsen skin dryness. The shower should
be in warm rather than hot water. Apply a moisturizer after shower or hands washing.
•Apply moisturizing creams, emollients or ointments moisturizers several times a day:
they are fundamental in dry skin treatment because they reconstitute cutaneous hydro-
lipidic film holding water in the skin. Cream moisturizers, when applied they disappear
when rubbed into the skin because of they are more popular than other treatments. They
protect damaged and sensitive skin and make skin softer and smoother. They preserve
natural skin lipids and limit dehydration trapping and sealing water in the stratum
corneum.
•Choose a non-alcohol-based moisturizer.
•Use a mild non-soap skin cleanser. Harsh soaps remove the oils from the surface of the
skin and dry it out.
•Avoid antibacterial soaps.
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21. •Place a humidifier in your home or add it to the central heating system to maintain the
air moisturized during the winter and in dry weather.
•Avoid rubbing or scratching the skin.
•Wear gloves, hats, and scarves in the winter.
•Avoid dehydration caused by drinking alcohol and by neglecting to replace fluids lost
through sweating.
•Avoid itchy clothing because it might get more itchy. Dry skin is especially sensitive to
contact irritants and it may worsen itching and redness.
ACNE
Acne, also known as acne vulgaris, is a long-term skin disease that occurs when hair
follicles are clogged with dead skin cells and oil from the skin. 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, including the face, upper
part of the chest, and back. The resulting appearance can lead to anxiety, reduced self-
esteem and, in extreme cases, depression or thoughts of suicide.
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22. What are the causes of Acne?
Genetics is thought to be the primary cause of acne in 80% of cases. The
role of diet and cigarette smoking is unclear, and neither cleanliness nor
exposure to sunlight appear to play a part. During puberty, in both sexes,
acne is often brought on by an increase in hormones such as testosterone.
A frequent factor is excessive growth of the bacterium Propionibacterium
acnes, which is normally present on the skin. Many treatment options for
acne are available, including lifestyle changes, medications, and medical
procedures. Eating fewer simple carbohydrates such as sugar may help.
Treatment of Acne
Treatments applied directly to the affected skin, such as azelaic acid,
benzoyl peroxide, and salicylic acid, are commonly used. Antibiotics and
retinoids are available in formulations that are applied to the skin and
taken by mouth for the treatment of acne. However, resistance to
antibiotics may develop as a result of antibiotic therapy. Several types of
birth control pills help against acne in women.
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23. Isotretinoin pills are usually reserved for severe acne due to greater
potential side effects. Acne commonly occurs in adolescence and
affects an estimated 80–90% of teenagers in the Western world.
Although acne becomes less common in adulthood skin disease
common during adolescence.
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Signs & Symptoms
-Scars Atrophic scars
-Hypertrophic scars
-Keloid scars
-Pigmentation
Causes
- Genes
- Hormones
- Infections
- Diet
- Stress
- Environmental factor
- Medication
Medication
-Benzoyl peroxide
- Retinoids
-Antibiotics
-Hormonal agents
-Azelaic agent
- Salicylic agent
- Other mediations
- Combination therapy

25. SKIN PIGMENTATION
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26. • Words Beginning With "Mela" Many words related to skin pigmentation begin
with the prefix “mela.”
• Melanin, melanocyte and melanoma are three you might hear a lot. All of these
words come from the Greek word "melas" or "melonas," which means black.
• The "in" in melanin refers to a chemical substance, so its literal meaning is a
chemical that makes you black, or dark.
• "Cyte" means cell, so a black cell is melanocyte, and "oma" means tumor, which
makes melanoma a tumor containing melanin .
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Skin pigmentation resides in the epidermis, or the thin outer segment of the three layers
that make up the skin.
The epidermis alone is made up of three tiny sub-layers.
Pigment does not reach the dermis, the middle layer of skin.
You get tan when your epidermis reacts to the ultraviolet (UV) rays of the sun. Your
melanocytes get a message from your skin that says, "Hey, potential damage here.
Protect me’Melanocytes then produce more melanin, which protects skin from sun
damage. Unfortunately, the body's natural protection is not enough to completely prevent
damage and disease caused by the strong rays of the sun.
Hyperpigmentation and Skin
Hyperpigmentation in skin is caused by an increase in melanin, the substance in the
body that is responsible for color (pigment). Exposure to sunlight is a major cause of
hyperpigmentaion, and will darken already hyperpigmented areas. Hyperpigmentation
can also be caused by various drugs, including some antibiotics, antiarrhythmics, and
antimalarial drugs.

28. Hypopigmentation and Skin Hypopigmentation in skin is the result of a
reduction in melanin production. Examples of hypopigmentation include:
•Vitiligo: Vitiligo causes smooth, white patches on the skin. In some people, these
patches can appear all over the body. It is an autoimmune disorder in which the pigment-
producing cells are damaged. There is no cure for vitiligo, but there are several
treatments, including cosmetic cover-ups, corticosteroid creams, calcineurin inhibitors
(Elidel cream, Protopic ointment) or ultraviolet light treatments. New topical treatments
using Janus Kinase inhibitors are being investigated.
•Albinism: Albinism is a rare inherited disorder caused by the absence of an enzyme that
produces melanin. This results in a complete lack of pigmentation in skin, hair, and eyes.
Albinos have an abnormal gene that restricts the body from producing melanin. There is
no cure for albinism. People with albinism should use a sunscreen at all times because
they are much more likely to get sun damage and skin cancer. This disorder can occur in
any race, but is most common among whites.
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29. • A handbook of cosmetics by B.M Mithal & R.N. Saha
• Cosmetic science concepts & principle by Dr. Kamla Pathak & Dr.
Ankur Vaidya
• www.google.com
• www.slideshare.com
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