• http://www.anatomy.wisc.edu/courses/gross/

Skin Diseases and Conditions

SKIN FACTS…

• Your skin is the largest organ of your body.• The average adult has 21 square feet of skin

which weights between 7 – 10 pounds, and has approximately 300 million skin cells.

• On average, each square-half inch of skin contains: 10 hairs, 100 sweat glands, and 3.2 feet of tiny blood vessels.

• Skin is the thickest on the palms and soles (1.2 to 4.7 mm) and thinnest on the lips and around the eyes.

SKIN FACTS…

• In your lifetime, you will shed approximately 40 pounds of skin.

• You have a totally “new” epidermis every 25 to 45 days.

• On a hot day, it is possible to sweat out up to 7 liters of body water in one day!

SKIN FACTS…

• Your hair appearance is due to the shaft shape (flat shaft = curly hair, oval shaft = wavy hair, round shaft = straight hair)

• Hair color itself is due to melanin; gray hair is a result of a lack of melanin

• Average hair growth is 2 mm per week• Nails grow at a rate of 0.5 to 1.2 mm per day,

with fingernails growing faster than toenails• Both hair and nails are simply HEAVILY

keratinized skin!

Blemishes

• Whitehead: occurs at your sebaceous (oil) glands when the duct is blocked by sebum (oils), dead cells, and/or bacteria

• Blackhead: when whitehead oxidizes and dries out

Athlete’s Foot

• Results from fungus infection

• Stimulated by warm, moist environment

• Skin becomes itchy, red, and peels

Boils

• Results from a deep bacterial infection

• Inflammation of hair follicles and sebaceous glands, common on back of neck

• Usually filled with white pus• Can be caused by ingrown

hairs, splinters, or plugged sweat glands

Cold Sores

• Also called fever blisters

• Caused by a herpes simplex virus infection

• Usually occur around the lips and mouth

• While the sores will heal, the virus will remain in the body

Canker Sore

• An oral ulcer caused by a break in the mucous membrane

• Many things can trigger, but most commonly caused by some sort of trauma to the mouth

Warts

• Rough, raised spots on skin caused by a viral infection, most commonly HPV

• There are over 130 strains of HPV, which can affect totally different areas of the body!

– Feet (plantar warts)

– Genital warts

– Some don’t have any effects at all!

• Warts can be treated with medications or by “freezing” it off

Contact Dermatitis

• Itching, redness, and swelling of the skin

• Caused by exposure of the skin to chemicals (irritants)

• Most common example is poison ivy

Impetigo

• Caused by strep and staph bacteria

• Pink, fluid-filled lesions that develop on skin

• Highly contagious, usually passed by contact

• Common in young children

Psoriasis

– Reddened epidermal lesions covered with dry, silvery scales

– Scaling occurs when cells in the outer layer of skin reproduce faster than normal and pile up on the skin's surface

– Cause unknown; may be hereditary

– Attacks triggered by trauma, infection, hormonal changes, weather changes, and stress

Frostbite

• Damage due to extreme cold

• At or below 0oC, blood vessels in skin constrict to preserve body temperature

• If this occurs for long periods of time, it can damage the tissue

• Likely to happen farthest from the heart (extremities)

Frostbite

Dandruff

• Flaking of the skin, usually at scalp

• Can be caused by dry skin, psoriasis, or contact dermatitis

Skin Conditions• Corns

– smaller than calluses – have a hard center surrounded by

inflamed skin– develop on parts of your feet that

don't bear weight, such as the tops and sides of your toes

• Calluses– develop on the soles of the feet,

especially under the heels or balls, on the palms, or on the knee

• Both corns and calluses are caused by rubbing and friction to an area, stimulating production of tough, keratinized skin

Stretch Marks• Fiber matrix located in dermis (dense

connective tissue) break down

• Creates a lack of support, which leads to dermal & epidermal stretching

• Caused by both skin stretching, as well as hormonal changes

Wrinkles• Loss of strength and

elasticity of skin due to aging

• Also, lower production of new cells at stratum basale layer

• Emphasized by age, sun damage, repeated facial movements, and natural effects of gravity

• More likely to have if fair-skinned, or spend time in the sun

Skin Conditions

• Albinism– Genetic condition that causes melanocytes in stratum

basale layer not to produce melanin– Results in light skin tone, blond hair– Easily sunburned– Higher risk of skin cancer– Usually have poor vision, due to a damaged retinal

pigment epithelium, which helps to nourish the retina– Can be found in ANY racial group

http://abcnews.go.com/2020/overcoming-social-stigma-albinism/story?id=8551660

WEIRD SKIN CONDITIONS

You don’t need to take notes on these!!!

“Tree Man”

• HPV causes warts on the body

• The man with this condition does not have an immune system deficiency that leaves him unable to control the warts

Congenital Insensitivity to Pain with Anhidrosis

• aka CIPA

• Genetic mutation that disrupts the development of the small nerve fibers that carry sensations of pain, heat and cold to the brain

• Patients feel no pain

• Patients also do not sweat, as they cannot sense the differences in temperature

Xeroderma Pigmentosum

• Autosomal recessive genetic disorder of DNA repair

• The ability to repair damage caused by UV light is deficient

• Leads to skin malignancies at a young age

• In severe cases, it is necessary to avoid light completely

• Symptoms include: severe sunburn after first (and short) exposure, many freckles, thick & dry skin, eyes painfully sensitive to the sun

Hypertrichosis

• aka Werewolf Syndrome• Nearly all the skin of the body

(except palms and soles of feet) are covered with hair

• There are three types of hair – scalp, vellus (all over body), and androgenic (growth stimulated by puberty and androgens – genitals, upper lip, armpits, etc.)

Hypertrichosis

• With hypertrichosis, vellus hair is also stimulated by androgens, leading to increased growth

Vitiligo• Disorder that causes

dispigmentation in patches of skin

• Melanocytes in a particular area die or are unable to function

• The precise cause of vitiligo is not yet fully understood

• There is some evidence suggesting it is caused by a combination of autoimmune, genetic, and environmental factors

• Common on extremities

Harlequin Icthyosis• Extremely rare genetic disorder where baby is

born with unusually high amounts of keratin in the skin (400 cases in 50 years)

• Skin forms thick, hard, diamond shapes with deep fissures due to its inflexibility, which increases their susceptibility to infection

• In can also cause the eyes, ears, and mouth to contract abnormally

• The survival rate of children born with this disease has improved over the years, but many will die within two days of birth, and treatment will be required for their entire life

• Overnight, they will grow as much skin as a normal body does in 14 days

• Patients must have a daily ritual of scrubbing and creaming their skin every four hours, to prevent their skin from cracking and becoming infected

Aquagenic Urticaria

• Hypersensitivity to the ions found in non-distilled water

• Water on the skin will cause a rash to appear

Colloidal Silver

• Paul Karason had a case of stress-induced dermatitis, but instead of going and getting antibiotics, he tried to treat it with a home-prepared batch of colloidal silver, an long-ago abandoned treatment

And now, back to your regularly scheduled

programming….

…I mean notes…

Burns

• Burn: tissue damage and cell death caused by intense heat, electricity, UV radiation, or certain chemicals

• 2 major issues with burns…– Body looses fluids containing proteins &

electrolytes, which can cause dehydration & shock

– Infections – leading cause of death in burn victims

Burns

• First-Degree Burn– Only epidermis is

damaged– Skin is red and

swollen– EX: sunburn

Burns

• Second-Degree Burns– Epidermis and

upper dermis are damaged

– Skin is red with blisters

Burns

• Third-Degree Burns– Destroys entire

skin layer– Burn is grey-white

or black

Burns

• Burns are considered critical if:– Over 25% of body has 2nd degree burns– OR…– Over 10% of the body has 3rd degree burns– OR…– There are third degree burns of the face,

hands, or feet

Skin Cancer

• Cancer: abnormal cell mass

• Two types– Benign

• Does not spread to rest of the body

– Malignant• Invade other body areas

Skin Cancer

• Skin cancer is most common type of cancer

• Most important risk factor is overexposure to UV radiation

Skin Cancer Types

• Basal Cell Carcinoma– Least malignant– Most common type– Stratum basale altered

so doesn’t form keratin– Usually treated with

surgical removal

Skin Cancer Types

• Squamous Cell Carcinoma– Arises from stratum

spinosum– Grows rapidly and

attacks lymph nodes if not removed

– Treated with surgery or radiation therapy

Skin Cancer Types

• Malignant Melanoma– Cancer of melanocytes (cells in stratum

basale responsible for melanin production)– Most deadly of skin cancers– Attacks lymph nodes and blood vessels– Begins where there is pigment (ex: moles)

Skin Cancer Types

• ABCD Rule– Used for recognizing melanoma by looking at

moles– (A) – asymmetry of mole– (B) – border irregularity– (C) – color, multiple colors on mole area– (D) – diameter is larger than 6 mm (size of

pencil eraser)

Wounds

• A wound is a type of physical trauma where the skin is torn, cut, or punctured

• There are several different types of wounds…

Wound types

• Incisions: caused by clean, sharp-edged object (ex: knife); if only epidermis involved, called “cut”

• Lacerations: irregular wounds, such as tearing of the skin

• Abrasion: epidermis is scraped off; often caused by a sliding fall onto rough surface (scrape)

Wound Types

• Puncture wound: caused by object puncturing skin, such as nail or needle

• Avulsion: tearing away of part of skin, parts of tissue get removed