Transcript Pharmacy Technician*s Course. LaGuardia Community College

Structure of the Skin
 The largest organ of the body. Its surface area is responsible for the
regulation of body temperature
 Has three layers
 Epidermis which contains keratinocytes. Keratinocytes contain keratin
which is a strong tensile protein responsible for much of the skin’s
physical barrier properties.
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Has five inner layers of the stratum corneum at the top and the stratum basale
The stratum basale is primarily made up of stem cells keratinoblasts, melanin
producing melanocytes and merkel cells for touch perception and langerhans
cells of the immune system
 Dermis is the layer of the skin that contains blood vessels, immune cells
and fibroblasts that produce collagen and elastin. Mast cells in this
layer release histamine which produces hives in response to allergic
reaction
 Hypodermis contains a fatty layer where adipocytes are located. This is
attached to the fascia of muscles
Picture courtesy of : http://www.best-antiaging-guide.com/images/human-skin.jpg
 Rapidly dividing stem cell keratinocytes in the basal layer
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grow and divide in this layer
As the days pass the mitotic cells migrate into the upper
layers of the epidermis dehydrate and begin to degenerate
By the time the keratinocytes arrive at the stratum
corneum they are dead and the keratin protein becomes
hardened and resistant to the environment and most
chemical insults
In the average person this migration of cells from the
basale layer to the stratum corneum occurs every 30 days.
In diseases like psoriasis this turnover rate is dramatic
increase to as little as 72 hours producing scaly skin
Functions of the skin
 Provides a physical barrier to infections
 Provides a barrier to the lose of water
 Temperature regulation via sweating
 Enable the sense of touch
 Vitamin D is synthesized from cholesterol
Immune function of skin
 The skin is not a sterile environment. On the skin, bacteria
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and fungi are present.
The normal flora of the skin provides a competitive
environment that protects against invasion by more
pathogenic organisms
Skin contains immune system cells including lymphocytes
(small degree), mast cells, and dendritic cells
Mast cells contain histamine and when the mast cells meet
an antigen they release histamine to produce a “wheal and
flare” reaction
Dendritic cells capture and process antigens, these cells
carry the “invader” to regional lymph node to initiate a
possible immune reaction
 Medical terminology involving the skin
 Macule: flat pigmented lesion
 Papule: Slightly raised lesion (<5 mm) (pimple)
 Maculopapular: combination of the two usually the papule is
in the center of the macule. Sometimes called morbilliform
(“measle like”)
 Erythema: beffy red section of skin
 Plaque: raised area of skin with clear borders.
 Nodule : a raised lesion (> 5mm)
 Vesicle: a small raised lesion filled with clear fluid (Blister)
 Bulla: a large raised lesion filled with clear fluid
 Pustule: a raised lesion filled with pus and bacterially infected
fluids
Diseases of the skin
 Autoimmune diseases of the skin
 Psoriasis. In psoriasis the immune system of the body attacks
the cells of the upper layers of the skin. The patient develops
rashes, intense erythema that leads to scales and blisters
localized to plaques areas. Can be painful
 T cells enter the epidermis and attack the keratinocytes of the
skin which produce chronic inflammation
 Drugs that suppress the immune system are used
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Topical steroid preparations: Desoximetasone (Topicort®),
Fluocinolide (lidex®).
Coal Tar agents: Anthralin cream (Psoriatec®)
Topical immune system medications: Pimecrolimus (Elidel®)
Vitamin D derivatives: Calcipotriene (Dovonex®)
 If topical therapy fails then internal therapy can be
tried:
 Methotrexate: 5-25 mg PO weekly
 Cyclosporin (Neoral ®, Sandimmune®, Gengraf ®): 5
mg/kg daily
 Mycophenolate (Cellcept®):250-500 mg/day
 All these agents are agents that suppress the immune
system
ATOPIC DERMATTIS (ECZEMA)
 Eczema is similar to psoriasis but less severe
 Eczema is believed to be a hereditary allergic reaction of
the skin to a normally benign antigen(s)
 Eczema is sometimes called “atopic dermatitis” and is
commonly associated with asthmatic patients
 Affected areas are itchy, red, and warm to the touch.
Lesions may enlarge and become scaly. The rash are very
itchy and the scratching can damage the skin further.
 Treatment includes:
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Topical Steroids
Vitamin D derivatives (Dovonex)
Vitamin A derivatives (retinoids): Differin® (Adapalene)
Topical immune modulators: Pimecrolimus (Elidel®)
Acne
 Inflammatory reaction in the skin called by excessive production of
sebum in the sebaceous glands of the skin located near hair follicles.
 Bacteria known as Propriobacterium acnes feeds on the fats and release
fatty acids which causes the skin to become inflammed
 A severe form of acne is nodulocystic acne which can form life long
scars
 Therapy:
 Benzoyl Peroxide (Oxy 10, Brevoxyl®, Acne 10®)
 Topical antibiotics combined with benzoyl peroxide i.e Benzaclin ® is
Clindamycin and benzoyl peroxide
 Topical Vitamin A derivatives: Retin A® (tretinoin )
 Oral Contraceptive in females: Ortho Tri Cyclen®
 Nodulocytic acne: Accutane ® (isotretinoin) A oral medication.
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Must be registered in the FDA’s iPLEDGE system
Bacterial Infections
 Most commonly seen infections are impetigo in
children and folliculitis in adults
 Both are caused by staphylococcal infections
 Cured by penicillin type antibiotics:
 Dicloxacillin 500 mg capule three times a day for 10 days
Viral Infections
 Chicken Pox: Varicella Zoster Virus is the cause.
Highly contagious by either touch or airborne
sneezing. No medication really effective, sometimes
acyclovir is tried in immunosuppressed patients.
Calamine lotion® is effective in suppressing itch and
crusting the lesions.
 Measles: very contagious. caused by the respiratory
virus Rubeola (not really a skin disease but has skin
manifestation)
 Shingles: Varicella Zoster virus is the cause. If this is
seen in young patients it can mean HIV infection
Cancers of the skin
 Any skin lesion that is large, raised, asymmetric,
changes in color, and has raggy edges should raise the
suspicion of cancer
 Malignant melanoma is a cancer of the pigment
producing cells of the skin and can be fatal if allowed to
spread to other areas of the body
 Basal Cell Carcinoma is a serious cancer; however, it can
be cured with chemotherapy
Miscellaneous disorders of the skin
 Wrinkles are caused by a lack of elastin in the skin and
reduce sebum production. It is common in old age
and sun exposed skin
 Rosacea is also known as “adult” acne. Its cause is not
known
 Burns
 Decibutus ulcers
Skin manifestations to drug
 Skin is often the window to seeing an incipient drug allergy
 Intense itching, wheals, hives may indicate an Type 1
hypersensitivity to a drug (anaphylactic reaction)
 Penicillins and other beta lactams
 Sulfa drug
 Antiseizure drugs (Carbamazepine)
 Upon subsequent exposure a life threatening reaction can
occur
 Morbilliform reaction: Type 4 hypersensitivity to a drug.
Usually occurs with 72 hours after drug exposure
 Usually not life threatening but uncomfortable to the patient
 Stevens Johnson Syndrome and Toxic Epidermal Necrolysis
 A drug reaction involving CD8 lymphocytes and epidermal
antigens and the drug
 SJS and TEN represent a dermatological emergency
 The reaction involves confluent separation of the epidermis
from the dermis and a denuding of the skin
 Therapy involves that used for severe third degree burns
 IV Corticosteroids is controversial
 IVIG 2 gm IV X1 or 0.4 g /day X 5 days has being tried with
some success.
 Common drug precipants: Penicillins, sulfonamide drugs,
phenytoin, lamotrigine, and some NSAIDS
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