1. Chapter 4 Skin and Body Membranes Pathology
Essentials of Human Anatomy & Physiology, 7th ed.
by Elaine N. Marieb

2. Skin and Body Membranes: Integumentary System, Pathology
Pathology – the study of disease; any deviation from a healthy, normal, or efficient condition. (pathos=suffering, logos=to study)

3. Pathologies of the Integumentary System:
Skin and Body Membranes: Integumentary System, Pathology
Pathologies of the Integumentary System:
1. Skin Color Abnormalities
2. Acne
3. Skin Abnormalities: ringworm, boils, cold sores, warts, contact dermatitis, pityriasis rosea, psoriasis, eczema, decubitis ulcers (bedsores)
4. Burns
5. Hypothermia
6. Heat exhaustion/heat stroke
7. Tissue repair
8. Skin cancer

4. Skin and Body Membranes: Integumentary System, Skin Color Abnormalities
Cyanosis
If hemoglobin is poorly oxygenated, blood and skin appears blue
Most apparent in areas of thin skin (lips or beneath nails)
Common during heart failure and severe breathing disorders
Response to extreme cold

5. Skin and Body Membranes: Integumentary System, Cyanosis

6. Skin and Body Membranes: Integumentary System, Skin Color Abnormalities
Erythema (redness): may indicate embarrassment (blushing), fever, hypertension, inflammation, skin injury, infection, or allergy

7. Skin and Body Membranes: Integumentary System, Skin Color Abnormalities
Pallor (AKA Blanching) (pale): may indicate emotional stress (fear, anger), anemia, low blood pressure, or impaired blood flow into the area

8. Skin and Body Membranes: Integumentary System, Skin Color Abnormalities
Jaundice (yellow cast): usually signifies a liver disorder in which excess bile pigments are deposited in body tissues because the liver is unable to excrete bile normally.

9. Skin and Body Membranes: Integumentary System, Skin Color Abnormalities
Contusions (bruises): reveal sites where blood has clotted in tissue spaces; clots are called hematomas.

10. Skin and Body Membranes: Integumentary System, Skin Color Abnormalities
Vitiligo: the immune system malfunctions, and antibodies attack normal melanocytes; person has patches of irregular white spots on their skin

11. Skin and Body Membranes: Integumentary System, Acne
Acne: an active infection of the sebaceous glands with “pimples.” Can be mild or severe, resulting in permanent scarring.

12. Skin and Body Membranes: Integumentary System, Acne
Whitehead: forms when a sebaceous gland’s duct becomes blocked with sebum
Blackhead: forms when blocked sebum oxidizes and dries

13. Ringworm Caused by fungal infection Beard: tinea barbae (folliculitis)
Skin and Body Membranes: Integumentary System, Skin Abnormalities
Ringworm
Caused by fungal infection
Beard: tinea barbae (folliculitis)
Body: tinea corporis
Feet: tinea pedis (Athlete’s foot)
Groin: tinea cruris (jock itch)
Scalp: tinea capitis
Easily communicable (skin, combs, unwashed clothing, shower and pool surfaces)
Pets can transmit disease, too (esp. cats)

14. Tenia corporis
Tenia pedis
Tenia barbae

15. Caused by bacterial infection
Skin and Body Membranes: Integumentary System, Skin Abnormalities
Boils and carbuncles
Caused by bacterial infection

16. Caused by herpes simplex virus
Skin and Body Membranes: Integumentary System, Skin Abnormalities
Cold sores
Caused by herpes simplex virus

17. Skin and Body Membranes: Integumentary System, Skin Abnormalities
Warts
Caused by a virus (usually some subspecies of human papillomavirus, HPV)
Warts are contagious, and usually infect the skin through areas of broken epidermis.
They typically persist for months, but can last for years, and often recur.

18. Exposure to allergen or irritant causes reaction
Skin and Body Membranes: Integumentary System, Skin Abnormalities
Contact dermatitis
Exposure to allergen or irritant causes reaction

19. Pityriasis rosea Common among young adults
Skin and Body Membranes: Integumentary System, Skin Abnormalities
Pityriasis rosea
Common among young adults
Believed to be caused by a virus
Not thought to be contagious
Most often last weeks. (3-12 weeks)
The rash starts with a single large patch called a herald patch. After several days, more skin rashes will appear on the chest, back, arms, and legs. Usually oval shaped patches. (Sun exposure helps.)

20. Triggered by trauma, infection, stress
Skin and Body Membranes: Integumentary System, Skin Abnormalities
Psoriasis
Cause is unknown
Scaly patches
Not contagious
Triggered by trauma, infection, stress

21. Usually occurs during first 5 years of life (90%)
Skin and Body Membranes: Integumentary System, Skin Abnormalities
Eczema
Immediate hypersensitivity response that results in “weeping” skin lesions and intense itching
Usually occurs during first 5 years of life (90%)
Familial predisposition

22. Decubitus ulcers (AKA Bedsores)
Skin and Body Membranes: Integumentary System, Skin Abnormalities
Decubitus ulcers (AKA Bedsores)
Occur when people lay in the same position for extended periods of time.
Blood flow is cut off from skin under pressure
Skin bacteria eat away at skin without bloodflow (no white blood cells!)

23. Skin and Body Membranes: Integumentary System, Burns
Tissue damage and cell death caused by heat, electricity, UV radiation, or chemicals
Associated dangers
Dehydration
Electrolyte imbalance
Circulatory shock

24. First-degree burns Second degree burns Third-degree burns
Skin and Body Membranes: Integumentary System, Burns
First-degree burns
Only epidermis is damaged
Skin is red and swollen
Second degree burns
Epidermis and upper dermis are damaged
Skin is red with blisters
Third-degree burns
Destroys entire skin layer
Burn is gray-white or black
Often painless, as sensory nerves in dermis are destroyed

25. 1st Degree Burn (superficial)
2nd Degree Burn (partial thickness)
3rd Degree Burn (full thickness)

26. Burns are considered critical if:
Skin and Body Membranes: Integumentary System, Burns
Burns are considered critical if:
Over 25% of body has second degree burns
Over 10% of the body has third degree burns
There are third degree burns of the face, hands, or feet
Burns complicated with musculoskeletal injuries
Circumferential burns

27. Rule of Nines Rule of Palm Way to determine the extent of burns
Skin and Body Membranes: Integumentary System, Severity of Burns
Rule of Nines
Way to determine the extent of burns
Body is divided into 11 areas for quick estimation
Each area represents about 9%
Rule of Palm
Alternate way to determine extent of burns
Patient’s palm is ~1% of body

28. Skin and Body Membranes: Integumentary System, Rule of Nines

29. Treatment of Burns Stop the burning process! Evaluate type of burn
Skin and Body Membranes: Integumentary System, Treatment of Burns
Treatment of Burns
Stop the burning process!
Evaluate type of burn
Flame: Wet down, smother, then remove clothing
Semi-solid (e.g. wax, grease, tar): cool with water. Do not remove substance
Water-based chemical burns: Flush with water for 15 minutes
Organic chemical burns: Flush with alcohol initially, followed by water (15 min.)
Dry chemical burns: Brush off remaining chemical, followed by water (15 min.)

30. Treatment of Burns 3. Remove clothing and jewelry
Skin and Body Membranes: Integumentary System, Treatment of Burns
Treatment of Burns
3. Remove clothing and jewelry
4. Wrap with dry, sterile dressing
5. Burns to eyes
If chemical burn, flush eyes with water for at least 20 minutes
If thermal burn, don’t try to open eyelids. Cover both eyes with sterile, dry gauze pads.

31. Skin Response to Extreme Temperature
Skin and Body Membranes: Integumentary System, Pathology
Skin Response to Extreme Temperature
Hypothermia – cold
Skin response: vasocontriction
Hyperthermia – hot
Skin response: vasodilation

32. Hypothermia Core Body Temperature Symptoms 99-96oF 96-91oF 91-86oF
Skin and Body Membranes: Integumentary System, Hypothermia
Hypothermia
Core Body Temperature
Symptoms
99-96oF
Shivering, vasoconstriction, skin appears pale, cyanosis
96-91oF
Intense shivering, difficulty speaking
91-86oF
Shivering replaced by strong muscular rigidity, muscle coordination is affected, thinking is less clear, possible total amnesia
86-81oF
Loss of contact with environment, stuporous state, muscle rigidity, pulse and respirations are slow
81-78oF
Loss of consciousness, most reflexes fail, heart slows until cardiac arrest

33. What to do for hypothermia:
Skin and Body Membranes: Integumentary System, Hypothermia
What to do for hypothermia:
Passive rewarming: remove any wet clothing, put on dry clothing, wrap in dry, warm blankets, do not massage extremities
Active rewarming: same as passive rewarming plus: apply heat to body by way of heat packs, hot water bottles, electric heating pads, warm air, even body heat, drink warm fluids (but no stimulants)…Do not warm too quickly! Cold, stagnant blood from the extremities will circulate to the core, dropping core body temperature. This could cause cardiac arrest.
Central rewarming: apply heat to lateral chest, neck, armpits, and groin. –Do not apply heat to extremities.

34. Localized cold injuries – affecting only particular parts of the body
Skin and Body Membranes: Integumentary System, Hypothermia
Localized cold injuries – affecting only particular parts of the body
Most commonly affects the ears, nose, face, fingers/hands, toes/feet
Early = superficial
Brought on by direct contact with cold air, water or cold object. Skin appears red (if light-skinned) or lighter in color (if dark-skinned). In more advanced instances, the skin takes on a grey/white blotchy appearance.

35. What to do for hypothermia: Superficial Local Hypothermia
Skin and Body Membranes: Integumentary System, Hypothermia
What to do for hypothermia:
Superficial Local Hypothermia
Warm affected area: Obtain a container of warm water (~ oF). It should feel comfortably warm. Immerse entire affected area into water until sensation and skin color return to normal.
Do not rub or
massage.

36. Localized cold injuries – affecting only particular parts of the body
Skin and Body Membranes: Integumentary System, Hypothermia
Localized cold injuries – affecting only particular parts of the body
Most commonly affects the ears, nose, face, fingers/hands, toes/feet
Late = deep
Skin becomes numb, due to reduced circulation. Continued exposure to cold leads to all loss of sensation, and the skin becomes dead white with a waxy appearance.

38. What to do for hypothermia: Deep Local Hypothermia
Skin and Body Membranes: Integumentary System, Hypothermia
What to do for hypothermia:
Deep Local Hypothermia
Only if you cannot get to a hospital should you warm the affected area: Obtain a container of warm water (~ oF). It should feel comfortably warm. Immerse entire affected area into water until sensation and skin color return to normal.
Do not rub or massage. Ice crystals may have formed in the affected tissue Agitation could further damage cells.

39. Skin and Body Membranes: Integumentary System, Hyperthermia
Normal body temperature ranges from about oF. Any temperature above that is considered hyperthermic. If body temperature rises above 104oF, it considered life-threatening – seek medical attention!
Core temperature can rise due to exercise, fever, or prolonged exposure to a hot environment. Hyperthermia follows two stages:
Heat Exhaustion
Heat Stroke

40. Characteristics of Heat Exhaustion:
Skin and Body Membranes: Integumentary System, Hyperthermia
Characteristics of Heat Exhaustion:
1. Skin appears moist, red (if light-skinned) or darker (if dark-skinned), and normal-cool to the touch
2. Heavy perspiration
3. Rapid, shallow breathing
4. Normal-weak pulse
5. Weakness and/or dizziness
6. Muscular cramps (usually in legs and abdomen)

41. What to do for Heat Exhaustion
Skin and Body Membranes: Integumentary System, Hyperthermia
What to do for Heat Exhaustion
Get to a cool environment, cool passively
2. Lie down on your back with legs elevated
3. Apply moist towels over cramps
4. Drink water (not too cold) if not nauseated

42. Characteristics of Heat Stroke:
Skin and Body Membranes: Integumentary System, Hyperthermia
Characteristics of Heat Stroke:
Skin appears moist or dry, pale, and hot to the touch
Little or no perspiration
Weakness and/or dizziness, possibly unconscious
No muscular cramps, but possibly seizures
Rapid, shallow breathing
Full, rapid pulse
Dilated pupils

43. What to do for Heat Stroke:
Skin and Body Membranes: Integumentary System, Hyperthermia
What to do for Heat Stroke:
Get to a cool environment, cool actively
Lie down on your back with legs elevated
Remove clothes and place cool packs to neck, groin, and armpits. If you cannot get to a hospital, immerse your entire body in cool water.
Drink water (not too cold) if not nauseated

45. Tissue Repair

46. Nearby capillaries dilate and become leaky.
Skin and Body Membranes: Tissue Repair
When continuous tissues like the skin, mucosae, and blood vessels are broken, the body initiates the inflammatory response.
Injured cells and certain white blood cells release inflammatory hormones (e.g. histamines).
Nearby capillaries dilate and become leaky.
Clotting proteins in the blood form a scaffold that traps platelets, leading to a clot. (stops bleeding and isolates pathogens)
White blood cells attack pathogens, dead cells, and other debris.

48. Fibrosis = Repair by dense fibrous connective tissue (scar tissue)
Skin and Body Membranes: Tissue Repair
Even as the clot is forming, tissue repair begins immediately. Depending on the tissue, and severity of injury, tissues will regenerate or be replaced by scar tissue (or both).
Regeneration = Replacement of destroyed tissue by the same kind of cells
Fibrosis = Repair by dense fibrous connective tissue (scar tissue)
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

49. Blood clot is replaced by granulation tissue.
Skin and Body Membranes: Tissue Repair
Tissue Regeneration
Blood clot is replaced by granulation tissue.
Capillaries grow in from nearby areas, forming new capillary bed.
Fibroblasts produce growth factors (encourage mitosis) and collagen fibers.
Some fibroblasts even help to pull the wound together.
Large white blood cells digest clot.
Granulation tissue is replaced either by original tissue type.
Fibrosis
Same as above, except granulation tissue is replaced by fibrous connective tissue.
Always occurs in cuts, scrapes, punctures, burns to some extent. May be visible at surface or not.
Over time scar tissue might be replaced by original tissue type.
Pure infections rarely lead to fibrosis. (only occurs in destructive infections)

50. Tissues that regenerate easily:
Skin and Body Membranes: Tissue Repair
Tissues that regenerate easily:
Epithelial tissue, fibrous connective tissue, areolar tissue, bone, blood-forming tissue
Tissues that regenerate moderately:
Smooth muscle, dense regular connective tissue
Tissues that regenerate poorly:
Skeletal muscle, cartilage
Tissues that are replaced largely with scar tissue:
Cardiac muscle, nervous tissue within the brain and spinal cord

51. Skin and Body Membranes: Tissue Repair
Sometimes, the body goes overboard with tissue repair. This can lead to hypertrophic scars AKA keloids.

52. Skin Cancer Skin cancer is the most common type of cancer
Skin and Body Membranes: Integumentary System, Skin Cancer
Skin Cancer
Skin cancer is the most common type of cancer
Biggest risk factor is overexposure to UV radiation in sunlight
Graph of skin cancer rates?

53. Basal cell carcinoma Least malignant Most common type
Skin and Body Membranes: Integumentary System, Skin Cancer
Basal cell carcinoma
Least malignant
Most common type
Arises from statum basale

54. Squamous cell carcinoma
Skin and Body Membranes: Integumentary System, Skin Cancer
Squamous cell carcinoma
Arises from stratum spinosum
Metastasizes to lymph nodes
Early removal allows a good chance of cure

55. Malignant melanoma Most deadly of skin cancers Cancer of melanocytes
Skin and Body Membranes: Integumentary System, Skin Cancer
Malignant melanoma
Most deadly of skin cancers
Cancer of melanocytes
Metastasizes rapidly to lymph and blood vessels
Detection uses ABCD rule

56. ABCD Rule A = Asymmetry B = Border irregularity C = Color D = Diameter
Skin and Body Membranes: Integumentary System, Skin Cancer
ABCD Rule
A = Asymmetry
Two sides of pigmented mole do not match
B = Border irregularity
Borders of mole are not smooth
C = Color
Different colors in pigmented area
D = Diameter
Spot is larger than 6 mm in diameter

57. So what can I do to take care of my skin?