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Spring 1 > Skin + Diseases > Flashcards

Skin + Diseases Flashcards

1
Q

What are the functions of the skin? (6)

A

Thermoregulation
Protection/Barrier - controls chemicals going in and out
Cutaneous sensations - mediates pain, warmth, cold
Blood Reservoir
Metabolic functions - synthesis of Vit D from modified cholesterol molecules
Safeguards internal organs

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2
Q

What is the integumentary system?

A

Skin and it’s derivatives - hair, nails, seat and oil glands

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3
Q

Name the main layers of the skin? (3)

A

Epidermis, Dermis and Subcutaneous tissue

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4
Q

What does the epidermis contain? (4)

A

Stratum corneum,
granular cell layer,
spinous cell layer
basal layer

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5
Q

What does the dermis contain? (6)

A 
Sebaceous gland
Nerves
Hair follicles 
Sweat glands
Erector pilli muscle 
collagen and elastin fibre
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6
Q

What does the subcutaneous tissue contain? (3)

A

Artries
Veins
Adipose tissue

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7
Q

What cells are present in the Epidermis?

A

keratinocytes
melanocytes
merkel cells
Langerhan’s cells

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8
Q

What are keratinocytes?

A

produce keratin, the fibrous proteins forms the protective layer. Comes from basal layer and move up to SC.

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9
Q

What are melanocytes?

A

Produce pigment melanin. protects nucleus from UV radiation

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10
Q

What are merkel cells?

A

low abundance cells - sensory receptors for touch

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11
Q

What are Langerhan’s cells?

A

Dendritic cells that come from bone marrow to epidermis. Antigen - presenting cells

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12
Q

What are the main layers of the dermis and what are their functions?

A

Papillary layer - forms dermal papillae to produce structure like nipples and ridges

Reticular layer - deepest layer - 80% of dermis. layer of irregualr connective tissue, contains collagen

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13
Q

Describe the function of eccrine sweat glands?

A

Produces sweat. drains into pores which lead to the surface of the skin

Hypotonic sweat - made of 99% water, urea, lactic acid, antibodies, salts and Vit C

Regulated by the sympathetic autonomic nervous system

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14
Q

Describe the function of apocrine sweat glands?

A

Produce sweat (Sweat + fats + proteins) which drains into hair follicles

Found in certain places: armpits, nipples, perianal area, ear canal, eye lids and parts of external genitalia

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15
Q

Give 3 examples of modified apocrine sweat glands

A

Ciliary eye glands - if bacteria infected = stye
Ceruminous glands - ear wax
Mammary glands - milk

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16
Q

Describe the activity of sebaceous glands?

A

All over the body except the palms and soles of feet

secrete sebum which lubricates and softens hair and skin - has bactericidal activity and under hormonal control (androgens)

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17
Q

Describe the structure of the nails

A

Thin keratinised layer with lower lipid levels than SC

Difficult to deliver drugs if nail is intact but easier when damaged

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18
Q

What is good about the transdermal route?

A

Transdermal route = controlled systemic delivery

  1. Large surface area
  2. Easy cessation is problematic
  3. Good patient compliance
  4. Avoids 1st pass hepatic metabolism
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19
Q

What are the 3 routes for permeation?

A

Sunt route - through the hair follicles, sweat glands
Transcellular- through the cells
Intercellualr - between the cells

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20
Q

What is the rate limiting factor for the transcellular and intercellular routes?

A

The multiple lipid bi-layer

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21
Q

Describe the stratum corneum lipids?

A

unique and different to other membrane lipids
two areas:
crystalline
liquid cyrstalline

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22
Q

Define Permeant

A

molecule moving into or through the skin

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23
Q

Define Flux

A

(J) - rate at which permeant crossing the skin e.g ug/cm2/h

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24
Q

Define Permeability coefficient

A

(Kp) the speed at which the permeant transports e.g cm/h

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25
Q

Define Diffusion coefficient

A

fundamental property of permeant in a particular membrane e.g. skin e.g. cm2/h

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26
Q

When we use the Fickian diffusion equation what assumptions do we make?

A
  1. only applies to isotropic media - but the skin is NOT and is heterogeneous
  2. That the stratum corneum is not affected by excipients but IT IS
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27
Q

What is the flux equation?

A

Flux = aD/yh

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28
Q

Describe how we measure the delivery through the skin using the FRANZ CELL

A
  1. Skin between the donor and the receptor
  2. receptor must dissolve the drug
  3. stir, keep at 32 degrees
  4. take samples and assay with time
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29
Q

What is the main drive for drug delivery?

A

Thermodynamic activity

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30
Q

What are key characteristics in selecting a good molecule candidate for skin? Hint MW, LogP, Aqueous solubility

A

. MW 300-500 2. LogP 1 - 3.5 3. Aqueous solubility > 100 mg/ml

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31
Q

Give the rationale for topical delivery (4)

A
  1. low oral bioavailability 2. Short half-life 3. Potential to induce insulin resistance at high doses in diabetic patients 4. long-term treatment
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32
Q

What is basal cell carcinoma (rodent ulcer)?

A

Basal cell carcinoma is a type of skin cancer. It’s the least malignant and most common form of skin cancer. It’s common in later life. Lesions are often on sun-exposed areas of the face. Lesions appear shiny, dome-shaped nodules that later develop during central ulcer with pearly, beaded edge It’s relatively slow-growing and metastasis seldom occurs before detection

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33
Q

What’s the treatment for basal cell carcinoma (rodent ulcer)?

A

Treatment: - full cure by surgical excision - radiotherapy useful in large superficial forms - cryo-therapy can be used for superficial forms

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34
Q

What is squamous cell carcinoma?

A

Squamous cell carcinoma arises from keratinocytes of stratified squamous epithelium. lesions are scaly red papules that can ulcerate and bleed found on head (scalp, ears, lower lips) and hands grows rapidly and metastases if not removed

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35
Q

What is malignant melanoma?

A

It is the most dangerous of all skin cancers. Exposure to UV radiation is a major cause It’s common on head, face, hands, back (men) and lower left (women). It’s highly metastatic and resistant to chemotherapy it occurs spontaneously in melanocytes and can begin wherever there is a pigment

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36
Q

What advice would you to people in regards to the dangers of sunbathing?

A
  • avoid sun exposure during hours 11am-3pm - wear a sun hat - apply high protection sunscreen e.g. SPF30 and re-apply at regular intervals
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37
Q

What is the USA criteria for recognising melanoma?

A

ABCD(E) A: Asymmetry - one half doesn’t match the appearance of the other half B: Border irregularity - the edges are ragged, notched, or blurred C. Colour - the colour (pigmentation) is not uniform. Shades of tan, brown and black are present. Dashes of red, white and blue add to a mottled appearance D: Diameter - the size of the mole is great than 1/4 inch (6mm). E: Elevation - any growth of a mole should be evaluated

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38
Q

Describe the 7-point checklist for melanoma (UK criteria)

A

Major criteria: - change in size - change in shape - change in colour Minor criteria: - diameter > 6mm - inflammation - oozing/bleeding mild itch or altered sensation

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39
Q

What type of infection is candidiasis?

A

Candidiasis are fungal infections (meaning thrush)

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40
Q

Where on the body does tinea capitis occur? At what age is it usually seen in and how is it spread?

A

the scalp. Usually seen in children and is spread by close-contact (especially in schools and households)

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41
Q

Where on the body does tinea corporis occur? Name some of its symptoms

A

the body (truck and/or limbs). Symptoms include isolated erythematous and scaly lesions or clusters of round or oval red patches

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42
Q

Where on the body does tinea cruris occur? Where is it more common in? What are some of the symptoms?

A

Groin. It’s common in warmer climates and involves itching in the groin thigh skin folds or anus. it’s red, raised, scaly patches that may blister and ooze.

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43
Q

Where on the body does tinea pedis occur?

A

feet (also known as athletes foot). It appears in toe clefts It presents as red, scaly eruption that itches.

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44
Q

What is tinea?

A

Tinea is used to describe skin mycoses. It’s sometimes called ‘ringworm’

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45
Q

What is onchomycosis?

A

nail infection

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46
Q

What is the treatment for localised ringworms?

A

Imidazoles (e.g. clotrimazole, miconazole) or terbinafine Apply 3 times daily for 1-2 weeks

47
Q

What is the treatment for Athletes foot?

A

Terbinafine 1% cream or spray

48
Q

What’s the treatment for widespread tinea infections

A

Adults: Oral antifungal -Terbinafine (250mg OD) or Itraconazole (100mg OD) for 1-2 months Children: Griseofulvin

49
Q

What is the role of NMF (natural moisturising factors)?

A
  • flexibility - cohesion - hydration - plays as a buffer (as pH increases, NMF decreases) - integrity
50
Q

What happens when there is a loss of filaggrin?

A

A loss of filaggrin results in: - corneocyte deformation (meaning flattening of the surface skin cells) - a reduction in NMF - an increase in skin pH which encourages serine protease activity (the enzymes which digests lipid-processing enzymes and desmosomes in addition to promoting skin inflammation)

51
Q

What are the symptoms of atopic eczema (dermatitis)? (4)

A
  1. Dry
  2. Scaly
  3. Erythematous
  4. Itchy rash (particularly noticeable on face, scalp, neck inside elbows and behind knees) N.B. If often resides in childhood but can continue into adulthood
52
Q

What are the 3 possible triggers for eczema (Dermatitis)?

A
  1. Internal inflammation 2. Eternally applied chemicals e.g. soaps 3. Environment e.g. humidity
53
Q

How does irritant contact eczema usually occur?

A

It results from damage to skin from topically applied liquids or chemicals in absence of an allergic mechanism

54
Q

How does allergic contact eczema occur?

A

Patients are allergic to a specific allergen. Whenever skin comes into contact with that allergen, then a eczematous rash occurs e.g. from nickel (jewellery, studs), leather, dyes, plans etc

55
Q

What are the available treatments for eczema (dermatitis)? (3)

A
  1. Emollients e.g. aqueous cream, emulsifying agents (to maintain hydration of SC and reduce water evaporation) - also helps avoid dryness and cracking of the skin 2. Topical steroids e.g. 1% hydrocortisone to reduce inflammation and itchiness 3. Sedating oral antihistamines e.g. chlorphenamine (Piriton) at night N.B. Avoid soaps, wool fabrics and synthetic materials (as it irritates the skin)
56
Q

Define seborrheic eczema (4)

A

t’s a common, harmless scaling rash, affecting the scalp, face and other areas (eyebrows, ears, folds of underarms and groin). - it’s non-contagious -may be aggravated by illness, physiological stress, fatigue, change of season, reduced general health - may predispose to psoriasis

57
Q

What advice would you give to someone with seborrhoeic eczema? (3)

A
  1. Reduce exposure to allergen e.g. houe dust mite, moulds, grass pollens, etc. 2. keep cool - wear loose cotton clothing avoid wool and dusty conditions, wear gloves when handling chemicals, solvents, detergents etc. 3. Use soap-free cleansers
58
Q

What’s the treatment for someone with seborrhoeic eczema on their scalp?

A

Medicated shampoos containing: - ketoconazole - selenium disulphide - zinc pyrthione - coal tar - salicylic acid to be used 2x week for at least a month

59
Q

What’s the treatment for someone with seborrhoeic eczema on their face, ears, chest and back?

A

Ketoconazole cream OD for 2-4 weeks Hydrocortisone cream can also be used - applied up to BD for 1-2 weeks

60
Q

Define systemic lupus erythematosus

A

mainly affects women between 35-45 years old symptoms include: - ‘butterfly’ rash on cheeks and nose - fatigue - rapid hair loss - non-specific join pains often exacerbated by sunlight/other stresses that increases skin circulation

61
Q

Define psoriasis

A

It’s a chronic, scaling disease associated with skin redness or inflammation. It appears raised, rough and reddened areas with fine silvery scales.

62
Q

Name the 5 common causes of psoriasis

A
  1. infection 2. trauma 3. emotional stress/ anxiety 4. cimate factors 5. certain drugs
63
Q

Describe plaque psoriasis

A

it’s the most common form. It manifests itself in form of scattered, raised, scaly patches, often on elbows, knee and scalp. Lesions can become itchy and sore

64
Q

Describe guttate (teardrop shaped) psoriasis

A

This consists of numerous, small discrete patches scattered all over the body

65
Q

Describe flexural (inverse) psoriasis

A

This affects areas of skin-to-skin contact e.g. armpits, buttocks. It tends to occur in later life

66
Q

Describe generalised pustular psoriasis

A

This is an acute, severe eruption of superficial pustules with reddening of the skin and high fever. Pustules don’t contain bacteria and it is not caused by infection. It can occur follwing the use of large quantities of strong steroid creams or steroid tablets to treat psoriasis.

67
Q

Describe pustular psoriasis

A

This is a chronic, localised form on the hands and feet. It occurs in the middle age usually

68
Q

Describe psoriatic arthritis

A

this is an inflammatory joint disease. It usually affects the small joints of hands and feet. The skin changes before the onset of joint pain

69
Q

Name some of the treatments available for the control of psoriasis

A

N.B. Treatment is more for the control, not cure 1. Emollients for hydrating skin

  1. Topical corticosteroids
  2. Calcipotriol (Dovonex) - a synthetic vitamine D3 analogue Applied 1-2 Daily for palpable lesions (once lesions have flattened, treatment can be stopped)
  3. coal tar (contains anti-inflammatory and anti-scaling)
  4. Salicyclic acid
  5. Dithranol to induce remission
  6. Retinoids (topically for mild-moderate plaque psoriasis)
70
Q

Name some of the phototherapy treatments available for the cure of psoriasis (2)

A

Phototherapy treatments includes: 1. UVB light for chronic stable psoriasis and guttate psoriasis 2. PUVA therapy

71
Q

When should systemic treatments for psoriasis be used? Name some of the systemic treatments available for the cure of psoriasis (3)

A

Systemic treatments are used for severe, unstable or complicated forms of psoriasis. 1. Acitretin 2. Cyclosporin 3. Methotrexate (in conjunction with folic acid)

72
Q

Define acne vulgaris

A

They include acne, pimples, zits They’re skin conditions characterised by the formation of: - comedones (blackheads and whiteheads) - papules (pinheads), skin elevation no fluid 5-10 mm diameter - nodules (like papules but bigger than 5-10mm) - cysts (cavity usually containing fluid) - it can be inflammatory or non-inflammatory

73
Q

How do acne vulgaris arise?

A

When hair follicles become obstructed with sebum/dead keratinocytes. They then become infected with normal skin anaerobe leading to inflammation

74
Q

What’s the most common trigger for acne vulgaris? Name other triggers

A

Puberty is the most common trigger. Others include: - hormonal changes in pregnancy/menstrual cycle - occlusive cosmetics, cleansing agents and clothing - stress - certain drugs e.g. oral contraceptives, corticosteroids

75
Q

What is the main aim for the treatment of acne?

A

To reduce sebum production, comedone infection, inflammation and infection

76
Q

What’s the treatment for mild acne vulgaris?

A

Benzoyl peroxide - usually started low and then increase dose if necessary (possible skin irritation but it subsides) - Benzoyl peroxide with clindamycin - Azelaic acid - topical retinoids e.g. tretinoin/ adapalene (however can be irritant) - topical antobacterials e.g. clindamycin, erthromycin (but tends to be ineffective if used alone) N.B Mild to moderate is treated usually topically. Also, topical corticosteroids should not be used

77
Q

What’s the treatment for moderate acne?

A

Antibiotics - tetracycline (1st choice_ - minocycline - doxycycline - erythromycin

78
Q

What’s the treatment for severe acne?

A

Isotretinoin (most effective but has serious side effects)

79
Q

What is rosacea?

A

It’s an inflammatory skin disease affecting the middle third of the face pimples can occur in affected areas also. There’s no blackheads or whiteheads N.B. Not to be confused with acne. In acne, if you have cysts/nodules, there will be black/whiteheads

80
Q

What are some of the symptoms of rosacea?

A
  1. persistant redness over areas of face and nose that normally blush (forehead, chin, lower half of nose) 2. dilation of blood vessels under skin appearing as thread veins if left untreated, it can affect eyes (gritty sensation, conjunctivitis), ears and nose that swells and grows
81
Q

Name the possible causes of rosacea (5)

A
  1. people who blush easily 2. emotional factors e.g. fear, stress, embarrassment 3. flare-ups can be caused by changes in weather 4. Helicobacter pylori and certain medications e.g. vasodilators and corticosteroids 5. certain foods/ beverages e.g. alcohol, tea, sicy foods, hot soups
82
Q

What are the treatments for rosacea?

A
  1. Topical metronidazole 2. topical azelaic acid 3. oral antibiotics (1st line being tetracycline) 4. Isotretinoin (accutane) N.B. Skin treatments for acne e.g. benzoyl peroxide can make rocasea worse
83
Q

What advice would you give patients with rosacea?

A
  1. Wear sunscreen with SPF > 30 to protect the face from the sun 2. Protect your face in the winter e.g. scarf 3. avoid irritating facial skin by rubbing or touching it too much 4. avoid facial products that contain alcohol or other skin irritants 5. when using moisturiser with a topical medication, apply the skin moisturiser after the medication has dried 6. use products that are labelled ‘non-comedogenic’ 7. avoid alcohol
84
Q

What are scabies? How are they transmitted?

A

Scabies are a human parasite that lives in burrowed tunnels in the stratum corneum. They’re tiny black papules (the mite) that are often visible in one end They’r transmitted through person-to-person physical contact. So in crowded areas e.g. schools

85
Q

Name the different forms of scabies and give a brief description of each (6)

A
  1. Classic scabies - erythematous papules first appear in finger web spaces, wrists, elbows, axillary folds, waistline. Face remain unaffected in adults
  2. Crusted (Norwegian) scabies - due to impaired immune system
  3. Nodular scabies - more common in infants/young children. May be due to hypersensitivity to retained organisms 4. Bullous scabies - occurs in children and also in elderly 5. Scalp scabies - occurs in infants and immuno-compromised patients. Can mimic seborrhoeic eczema 6. Scabies incognito - widespread atypical form resulting from application of topical corticosteroids.
86
Q

What’s the treatment for scabies?

A

1st line treatment: topical scabicides - Permethrin. You apply it to the entire body from the neck down and wash it off after 8-14 hours. Repeat this treatment after 7 days. N.B. For infants and young children, permethrin should be applied to the head and neck, avoiding periorbital and perioral regions. Special attention should be given to fingernails, toenails, and umbilicus. Lindane is not recommended in children under 2 years old or in patients with a seizure disorder because of potential neurotoxicity. Precipitated sulphur 6-10% in petrolatum is applied for 24 hours for 3 consecutive days. It’s safe and effective. Ivermectin is indicated for patients who do not respond to topical treatment, are unable to adhere to topical regimes, or are immunocompromised with Norwegian scabies. Pruritus can be treated with corticosteroid ointments and/or oral antihistamines

87
Q

Describe lice (pediculosis)

A

They infest the scalp, the body, the pubis and the eyelashes. There are 3 kinds and they are all different in terms of morphology and clinical features e.g. head/pubic lice live on the body, whereas body lice live in clothing

88
Q

What are the available treatments for headlice and how do you use it?

A
  1. Mechanical removal (wet combing) - avoids irritation by chemicals 2. Dimetocone (4%) apply to dry hair and scalp, allow to dry naturally, wash off after 8 hours. Repeat after 7 days 3. Malathion (0.5%) apply to dry hair and scalp, allow to dry naturally, wash off after 12 hours. Unpleasant odor. 4. Primethrin (active, but not recommended for head lice
89
Q

What’s the treatment of body lice?

A

There’s no topical treatments since body lice are found in clothing!

90
Q

What’s the treatment for pubic lice and how do you use it?

A
  1. Malathoin - apply 0.5% aqueous preparation over the whole body. Dry naturally and wash off after 12 hours. Repeat this application after 7 days 2. Permethrin - apply 5% cream over the whole body, dry naturally, leave 12 hours or overnight then wash off. Repeat after 7 days
91
Q

Define boils

A

Boils are also called furuncles and carbuncles. They’re tender nodules caused by staphylococcal infection, often due to an infection of the hair follicle A carbuncle is a cluster of furuncles connected subcutaneously, causing scarring. It can be accompanied by fever Furuncles are common on the neck, face, breasts and buttocks It can affect healthy people but more common in obese people

92
Q

Define impetigo an ecthyma

A

This is a superficial skin infection with crusting caused by Streptococci or Staphylococci, or both. Ecthyma is an ulcerative form of impetigo. There’s no predisposing lesion identified in most patients but can follow any break the skin. Ecthyma is characterised by small, purulent, shallow, punched-out ulcers with thick, brown-black crusts and surrounding erythema. Impetigo and ecthyma can cause mild pain or discomfort. Pruritus is common and scratching can spread the infection

93
Q

What are risk factors that can increase the chances of developing impetigo and ecthyma? (3)

A
  • Moist environment - Poor hygiene - Chronic nasal carriage of staphylococci
94
Q

What’s the treatment of impetigo and ecthyma? (3)

A
  • Fusidic acid is used to treat localised diseased (2% 3-4 times daily) - Mupirocin can be used topically is it’s MRSA (2% TDS for 10 days) - Flucloxacillin or clarithromycin (oral antibiotics) is used if it’s extensive
95
Q

Define photosensitivity

A

It’s a reaction of skin to sunlight. The individual can get redness, rash and urticaria within minutes of exposure to sunlight. In extreme cases, it can lead to dizziness, wheezing and other systemic problems

96
Q

Describe the different types of burns available (4)

A

Thermal burns are from any external heat source e.g. flames, liquids, solid objects, gases etc. -

Radiation burns commonly result from prolonged exposure to solar UV radiation (sunburn). It can be from other sources e.g. tanning beds, X-rays, non-solar radiation -

Chemical burns occur from strong acids or alkalis e.g. cement, phenols, cresols. Skin/deeper tissue necrosis due to agents may progress over hours

  • Electrical burns can result from electrical generation of heat. Skin/deeper tissue damage may result despite minimal apparent cutaneous injury
97
Q

Why are burns bad?

A

Burns cause protein denaturation and coagulation necrosis. Platelets aggregate, vessels constrict around coagulated burned tissue. Get inflammation around damaged zone and can get bacterial infection through damaged epidermal layer. Leads to oedema and external fluid leakage. Heat loss can be significant because thermoregulation of damaged dermis is impaired and fluid leakage increases evaporative heat loss.

98
Q

What the classifications of burns and give a brief definition of each (2)

A

First degree is the most common type of burn. Burns are red, blanch markedly with light pressure, are painful and tender. Limited to epidermis

Second degree (partial thickness) - involve part of dermis.
Sub-divided into superficial and deep.
Superficial 2nd degree burns involve upper half of dermis; heal within 2-3 wks. Rarely scar in this period unless become infected. Skin is red/white, blanch with pressure. Intense pain and tender. Vesicles develop within 24 hr.
In contrasts, deep 2nd degree burns involve bottom half of dermis, take >3 wk to heal and scarring is common. May be white, red or mottled. Do not blanch and less painful/tender than more superficial burns. Vesicles may develop. Burns tend to be very dry.

Third degree (full thickness) burns extend through the entire dermis and into the underlying fat

99
Q

What are the steps for the treatment of burns

A

First priorities are same as for any injured patient (airway, breathing, circulation) - Remove clothing that covers burn - Flush chemicals (except powders that are brushed off first) with water - Burns caused by acids, alkalis etc should be flushed with copious amounts of water for at least 20 mins - Small burns can be immersed early in cold water until pain subsides (although this will not limit depth of injury) - IV fluids given to patients who are in shock or with burns >15% BSA - Hypothermia/pain treated appropriately - After cleaning wound, cover burn with topical antibacterial salve (e.g. 1% silver sulphadiazine) and sterile dressing. Prophylactic antibiotics not given - Depending on severity, patient might need to be hospitalized - Dressings are changed daily. Burned cleaned completely with water. Apply a new layer of antibacterial salve and re-apply the clean dressing - Surgery (grafting) is indicated for all 3rd degree burns and for burns that do not heal within 3 weeks (most deep 2nd degree burns)

100
Q

Give the different types wounds (6)

A

Abrasion; graze. Superficial, epidermis scraped off
Laceration; irregular tear
Avulsion; removal of all skin layers by abrasion (bottom right)
Incision; regular slice with clean sharp object (e.g. knife, bottom left)
Puncture; e.g. Nail or needle
Amputation; cut off!

101
Q

What are the 4 different wound classifications?

A
  1. Necrotic: dead (ischaemic) tissue, usually black and covered with dead epidermis
  2. Sloughy: often yellow due to accumulation of cellular debris, serum excudate, bacteria
  3. Granulating: typically deep pink or red with a high vascularized granular appearance
  4. Epithelializing: cells migrating from wound edges to start the process of re-epithelialisation, see a pink wound bed
102
Q

What are the 4 steps in wound healing?

A
  1. Haemostasis 2. Inflammation 3. Proliferation a. Granulation b.Epithelialisation c. Collagen production d. Wound contraction 4. Maturation/ remodelling
103
Q

Define haemostasis

A

When an injury occurs, vasoconstriction takes place and then platelet aggregation happens. A haemostatic plug/clot seals the damaged vessel.

104
Q

Define inflammation

A

This is characterized by redness, heat , pain and swelling. It typically lasts 4-5 days. It initiates the healing process by stabilising the wound through platelet activity (thus stopping bleeding and triggers the immune response). Within 24 hours of the initial injury, neutrophils, monocytes and macrophages are on the scene to control bacterial growth and remove dead tissue. It’s characteristic red color and warmth is caused by the capillary blood system increasing circulation & laying foundation for epithelial growth.

105
Q

Define granulation

A

This is the formation of new capillaries that generate and feed new tissue - angiogenesis. Fibrous connective tissue replaces the fibrin clot and grows from the base of the wound.

106
Q

Define epithliazation

A

This involves the formation of an epithelial layer that seals and protects the wound form bacteria and fluid loss. It’s essential to have a moist environment to foster growth of this layer. It’s initially a very fragile layer that can be easily destroyed with aggressive wound irritation or cleansing of the involved area.

107
Q

define collagen synthesis

A

This creates a support matrix for the new tissue and provides a new tissue its’ strength. This stage is the actual rebuilding of the skin barrier. It’s influenced by the overall patient condition (age, nutrition etc.) and by the condition of the wound bed.

108
Q

Describe maturation

A

This is the final stage of wound healing. It begins around day 21 and may continue for up to 2 years. Maturation begins when collagen synthesis and degradation equalize. In this stage, disorganized collagen fibers are rearranged, cross-linked and aligned along ‘tension lines.’ This is termed re-modelling. As the activity at the wound site reduces, the scar loses its red appearance as blood vessels that are no longer needed are removed by apoptosis.

109
Q

Name the 3 types of wound healing

A

Primary healing: also called healing by first intention, or primary wound closure Secondary healing: healing by secondary intention or secondary wound closure Delayed primary healing: sometimes called healing by third intent or tertiary intention

110
Q

Define primary wound closure and include its advantages

A

This is when wound edges are brought together so that they are adjacent to each other. Most surgical wounds heal by primary intention. Wound closure is performed with stitches, staples or adhesive tape. Advantages include: - Minimises scarring Lowers infection risk

111
Q

Define secondary wound closure and include its advantages

A

This is where the wound is allowed to granulate. Granulation results in a broader scar than primary intent. Healing can be slowed due to drainage from the infection. The wound care must be performed daily to encourage wound debris removal to allow for granulation tissue formation. Advantages include: - Allows removal of foreign bodies Prevents haematoma development (collection of blood outside of blood vessels that would be trapped when wound closed immediately by, for example, stitches)

112
Q

Define delayed primary wound closure

A

This is where the wound is purposely left open. The wound is initially cleaned, debrided (remove dead, damaged or infected tissue) and observed. By the 4th day, phagocytosis of contaminated tissues is well underway, and epithelisation, collagen deposition, and maturation are occurring. Usually, the wound is closed surgically after 4-5 days. But if ‘cleansing’ of the wound is incomplete, chronic inflammation can then occur. This results in significant scarring

113
Q

Describe what hypertronic scars are

A

This is due to the over-production of collagen during the healing causing scars to be raised and above the skin surface. It’s typically a red, raised lump on the skin.

Spring 1 (13 decks)

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