Skin

Question 1

Which structures make up the integumentary system?

Answer 1

1. Skin
2. Nails
3. Hair
4. Glands

Question 2

Role of integumentary system?

Answer 2

• Helps other body systems maintain their function
• eg. helps immune - first line defence against pathogens (hair, nails)
• helps absorb vitamin D (bone health)
• Tiny nose hairs helps prevent dust entering lungs.

Question 3

3 main layers of skin

Answer 3

1. Epidermis
2. Dermis
3. Hypodermis

Question 4

Epidermis

Answer 4

1. Top layer of skin
2. made of melanocytes, keratinocytes, langerhans
3. gives skin its colour + provides waterproof barrier

Question 6

Dermis

Answer 6

1. Middle layer + thickest
2. contains sweat + oil glands and hair foliciles

Question 7

Hypodermis

Answer 7

1. Bottom layer
2. fatty layer - helps insulate the body

Question 8

3 main glands

Answer 8

1. Sebaceous glands
2. Eccrine glands
3. Apocrine glands

Question 9

Sebaceous gland

Answer 9

1. Found on face, chest, upper back
2. produce sebum which keeps skin + hair soft

Question 10

Apocrine glands

Answer 10

Found primarily in the axilla (armpit)
sweat

Question 10

Eccrine gland

Answer 10

all over body - mostly on palms and sole of feet
waste product elimination and temperature control (sweat)

Question 11

Keratinocytes

Answer 11

1. Epidermal cell which produces keratin and is formed by the basal layer
2. They move up through the epidermis and eventually become the outer keratinised layer of corneocytes - Cornification
3. This process takes 35 days
4. Corneocyte layer is largely responsible for the physical protective barrier of skin.

Question 12

4 types of hypersensitivity reactions

Answer 12

• Type I - intermediate
• Type II - antibody dependent cytotoxicity
• Type III - immune complex disease
• Type IV - cell mediated or delayed

Question 13

Type I - intermediate reaction MOA, appearance

Answer 13

Mechanism - antigen exposure causes allergen-specific IgE on the surface of mast cells to degranulate
Appearance:
Mild - urticaria (hives)
Severe - anaphylaxis
Treatment - Antihistamines

Question 14

Type II - antibody dependent cytotoxicity

Answer 14

Mechanism - IgG antibodies direc

Question 15

Type III - Immune complex disease

Answer 15

Mechanism - Immune complexes are depositied on the walls of capillaries in the skin. Complement activation, platelet aggregation and lysosomal enzyme release cause vascular damage ( leucocytoclastic vasiculitis)

Appearance: discoloured spots

Question 16

Type IV - Cell mediated or delayed

Answer 16

24-48hr after alergen contact
Mechanism - lymphocytes in the lymph nodes are sensitised by dendretic cells and start immunosurveilance of the tissue. On reencounter with their sensitising antigen-MHC complex and they become activted

Question 17

Routes of infection

Answer 17

1. Violation
2. Obstruction

Question 18

What is most commone bacteria in skin conditions

Answer 18

1. Staphylococcal
2. Streptococcal

Question 19

Clinical presentation fo bacterial skin conditions:

Answer 19

Erythema, pain, swelling, warmth

Question 20

Complications of bacterial skin conditions

Answer 20

1. Abcess
2. sepsis
3. post-inflammatory hyperpigmentation, MRSA (difficult to treat bacteria)

Question 21

Viral skin infections

Answer 21

1. Most common in people who are engaged in activity around livestock, in the wild, or contact
2. Childhood coindtions: measles, rubella, chickenpox

Question 22

Systemically infecting viruses:

Answer 22

Hand foot and mouth disease caused by enterovirus infection

Question 23

Locally infecting viruses:

Answer 23

1. Herpes simplex (cold sores)
2. Herpes zoster (shingles)
3. warts

Question 24

Fungal infections most common places to occur

Answer 24

1. Skin (ringworm, athleets foot, thrush, pityrasis versicolor) 2. Nail 3. Scalp (scalp ringworm)

Question 25

Primary skin lesions

Answer 25

1. moles, birthmarks 2. aquired during life, eg from wart, acne, allergic reactions, psoriasis etc 3. Enviromental agents eg, sunburn, pressure, temp extremes)

Question 26

Secondary skin lesions

Answer 26

1. Either as a natural progression or result of person picking or scratching at primary lesions 2. seperation of nail plate from nail bed or psoriasis scales

Question 27

Why are we increased risk of skin infections with age?

Answer 27

1. Melanocytes decline 2. Langerhans cells decrease in density and responsivness 3. Decreased density of the dermal layer 4. Loss of elastic tissue and collagen 5. increased exposure to UV, smoking, pollution 6. increase in disorders that can lead to skin conditions 7. Increase in prescription drugs which can have skin side effects 8. reduced motility

Question 28

Differences found in darker skin compared to lighter

Answer 28

1. thicker dermins and smaller collagen fibres 2. increased melanocyte activity and melanin content, increased fibrolast density

Question 29

Acne Vulgaris

Answer 29

1. most common skin disorder 2. seburn and epithelial cells clog glands 3. produces whiteheads and blackheads 4. anaerobic bacteria trigger inflammation (pimple) 5. largley gormonally induced (androgens stimulate sebum production) 6. treatment: antibiotics, topical creams, birth control pills

Question 30

Acne skin Type II

Answer 30

* Presence of post-inflammatory erythema but lack of post-inflammatory hyperpigmentation (PIH)

Question 31

Acne skin type IV

Answer 31

see pic

Question 32

acne skin type v

Answer 32

see pic

Question 33

Treatment for Acne

Answer 33

Minor: OTC topical benzoyl peroxide Moderate/Severe: 1. topical retinoids 2. topical/oral antibiotics 3. azaelic acid 4. in woman, combined oral contracneptive 5. Specialist - Isotretinoin caps

Question 34

Eczema treatment

Answer 34

Symptomatic treatment - there is no cure Self-care: 1. Reduce scratching, keep nails short, anti-scratch mittens on babies) 2. avoid triggers eg. soap, detergent, pets Topical: 1. emolients used at least BD for dry skin even if eczema improves 2. Wash with emolients instead of soap (dermol 500, Qv gentle wash) 3. Topical corticosteroids to reduce swelling, redness, itching during flares.

Question 35

How should you apply emolients

Answer 35

Use spoon or spatula as parrafin = fire risk

Question 36

Eczema apperance in different skin tones: Black

Answer 36

Dark purple, grey higher risk of post-inflammatory dyspigmentation (flat dark spots)

Question 37

Eczema appearance in Light brown/olive skin tones

Answer 37

Dark red/brown circular ot folicular patterns may be more common

Question 38

How does psoriasis present in Type 1

Answer 38

see pic

Question 39

psoriasis presentation type 2

Answer 39

see pics

Question 40

Psoriasis treatment

Answer 40

* Primary care or specialist referral * Topical * Phototherapy (UV light) * Systematic

Question 41

Variations in clinical presentation in: acne, eczema, psoriasis

Answer 41

see table

Question 42

Ringworm appearance

Answer 42

Skin type 2 - Redness and scaly erythematous, clearly visible red circular borde, pale inner circle Skin type V-IV circular, scale lesion, raised edges No visible inflammation, redness

Question 43

Ringworm treatment

Answer 43

Pharmacy first: Miconazole 2% cream, terbinafine, clotrimazole may be required to use for for > 4 weeks

Question 44

Variations in clincial presentation of skin conditions: Tinea versicolor, Melasma, Contact dermatitis, Rosacea

Answer 44

see pic