An Introduction to Dermatology

Describe features of the skin (1)

Largest organ in the body, 16% of total body weight, cell turnover of 28 days (important to consistently apply drugs to skin/re-use medicines). 20-33% of population affected by skin disease during lifetime

1 of 40

Describe features of the skin (2)

GPs spend 10% of their time dealing with skin conditions. 735 skin related consultations in 1 month across 20 pharmacies. Financial burden on NHS. Affects QOL

2 of 40

Describe features of the skin (3)

Eczema – most common skin condition in primary care. OTC medicines for skin conditions. Some medicines require specialist advice. Skin condition could indicate other conditions e.g. chickenpox

3 of 40

Describe features of the skin (4)

Skin conditions affect QOL in comparison to other diseases – more visual. QOL taken into account when determining skin treatment

4 of 40

Outline the skin structure

Epidermis, dermis, subcutaneous, sensory nerves, motor nerve. Stratum corneum, sweat pores, merocrine sweat glands, arrector pili muscle, hair bulb, apocrine sweat gland, adipose tissue, arteriole, venule. Medications target different layers

5 of 40

What is psoriasis?

Chronic inflammatory skin disease. Increased epidermal cell turnover (thickening/scaling), stratum corneum replenishing faster than normal. Inflammatory cell infiltration. Relapsing/remitting. Traps dry skin (red/hot/inflamed)

6 of 40

What is the incidence of psoriasis?

Affects 2% of population. Peak onset in young adults, can occur at any age, usually 2nd-3rd decade of life. Men and women equally affected

7 of 40

What are the causes of psoriasis?

Antigen, T-cell activation, release of inflammatory cytokines, epidermal hyper-proliferation. Genetic factors involved - 1/3 have family history

8 of 40

What are the precipitating factors for psoriasis? (1)

Injuries (cuts, abrasions, sunburn). Streptococcal infection. Hormonal events (often improves during pregnancy, relapses in postpartum period). Sunlight (usually improves but 10% will get worse)

9 of 40

What are the precipitating factors for psoriasis? (2)

Drugs (beta blockers, lithium, antimalarials, withdrawal of systemic steroids - rebound effect). Alcohol, smoking, stress

10 of 40

Describe features of chronic plaque psoriasis (1)

90% of cases. Red plaques - well defined edge covered with silvery scales (vary in size). Scale - flakes of stratum corneum, accumlated or shed. Can affect any area (usually skin folds, scalp, knees/skins, outside of elbows, lower back)

11 of 40

Describe features of chronic plaque psoriasis (2)

Plaques can crack and bleed - scratching/removing scales - pinpoint bleeding (could cause infection). Usually symmetrical in distribution. Not many painkillers effective for skin conditions

12 of 40

What are the other types of psoriasis? (1)

Plaque psoriasis, scalp psoriasis, guttate psoriasis (drop-like, acute form, occurs in children/young adults, after streptococcal infection, multiple/pink/scaly drop-like plaques over trunk/limb)

13 of 40

What are the other types of psoriasis? (2)

Flexural (affects skin folds e.g. armpits, groin, under breasts, shiny and moist, prone to secondary infection)

14 of 40

What is the difference between eczema and dermatitis?

Eczema (endogenous cause, atopic eczema). Dermatitis (exogenous cause, allergic contact dermatitis, irritant contact dermatitis)

15 of 40

Describe features of eczema (1)

Accounts for 30% of GP consultations. Impaired barrier function of skin. May be due to genetic defect in production of lipids that normally holds keratinocytes firmly together. Causes water loss, dry cracked and itchy skin

16 of 40

Describe features of eczema (2)

Easier entry of irritants/allergens cause an inflammatory response and infections. Acute vs chronic

17 of 40

Describe features of acute eczema (1)

Inflammatory cells infiltrate epidermis and dermis, dermal blood vessels dilate, fluid leaks out of dilated blood vessels. Symptoms - red/hot/swollen/very itchy skin, blisters form which can rupture, exudate/crusting

18 of 40

Describe features of acute eczema (2)

Immediate phase, blisters form/can rupture, leaky skin (dilated blood vessels, changes in osmosis, water moves out of vessels/onto the skin)

19 of 40

Describe features of chronic eczema (1)

Chronic, intense scratching leads to thickening of epidermis, can fissure. Symptoms - dry/thick/leathery skin, pain, secondary infection

20 of 40

Describe features of chronic eczema (2)

Skin layer is thicker than normal, compensate for lack of integrity

21 of 40

Atopic eczema affects which people in the population?

Affects 15% of children, nearly all cases develop before 5 years of age, majority recover before teens. Affects both sexes equally

22 of 40

What are the causes of atopic eczema?

Genetic factors involved - 70% have FH of eczema/asthma/hay-fever/urticaria, suggested due to immature immune system and high IgE levels. Symmetrical appearance. Mainly affects cheeks of babies. Adults - eyelids/flexures

23 of 40

What are the precipitating factors for eczema?

Dry skin, stress, extremes of temperature, infection. Patient’s occupation can impact on presentation of eczema e.g. exposure to chemicals in the surroundings

24 of 40

Describe features of allergic contact dermatitis (1)

Allergy to usually harmless substances that have been in contact with the skin e.g. nickel, components of creams/ointments, fragrances, rubber gloves, plants. Consider area affected, timing, exposure. Visible in 48-96 h after contact with allergen

25 of 40

Describe features of allergic contact dermatitis (2)

Activation of T-cells -> release of cytokines. Patch testing can be useful in some patient. Need to determine cause (exposure of skin during patient’s daily routine)

26 of 40

Describe features of irritant contact dermatitis (1)

No allergy involved. Caused by substances which are irritant to skin - chemical/mechanical/irritation e.g. detergents, abrasives, water. Irritants remove oils/lipids form stratum corneum, deeper penetration of irritant, triggers inflammation

27 of 40

Describe features of irritant contact dermatitis (2)

Consider area affected, timing and exposure. More common on women, young children, certain occupations. Irritant penetrates skin, triggers inflammatory process

28 of 40

What is acne?

A skin eruption characterised by inflammation of the sebaceous glands. Usually affects face/back/chest - where sebaceous glands most numerous and active

29 of 40

What is the incidence of acne? (1)

Very common - will affect most people at least once in a lifetime. Main age of onset is puberty. Males and females equally affected. Not exclusively a teenage problem. Mild - non-inflammatory, <20 comedones

30 of 40

What is the incidence of acne? (2)

Severe - extensive nodular cysts, scarring, >125 lesions)

31 of 40

What are the symptoms of acne?

Greasiness, comedone formation. Blackhead - small open follicular papules containing a central black keratin plug. Pigmentation from oxidised melanin (not dirt). Whiteheads - small closed follicular papules, no visible central keratin plug

32 of 40

Describe the pathogenesis of acne (1)

Sebaceous gland increases excretion, microcomedone formation, follicular hypercornification, non-inflammatory lesion, pigment, waxy solidified sebum, follicular occlusion

33 of 40

Describe the pathogenesis of acne (2)

Inflammation, inflammatory lesions, proliferation of Propionibacterium acnes, polymorph infiltrate, pus. Each of these aspects are considered as drug targets, treatments - oral retinoids, ethinyloestradiol cyproterone acetate, topical retinoids

34 of 40

Describe the pathogenesis of acne (3)

Benzoyl peroxide, topical/oral antibiotics

35 of 40

Describe the pathogenesis of acne (4)

Sebaceous gland increases excretion stimulated by androgens (hormonal), follicular occulusion, build up of lipids, inflammation, inflammatory lesion

36 of 40

Describe the pathogenesis of acne (5)

Bacteria can also get trapped in the hair follicle, causing inflammatory response, increase size of hair follicle, can burst above/below the skin, goes to surface/formation of skin

37 of 40

Describe the pathogenesis of acne (6)

Bursts – formation of a scar deep in the skin (caused by broken hair follicles)

38 of 40

Is acne caused by eating too much chocolate/sweets?

No

39 of 40

Is acne caused by not washing your skin?

No

40 of 40

Get Revising

An Introduction to Dermatology

Other cards in this set

Card 2

Front

Back

Card 3

Front

Back

Card 4

Front

Back

Card 5

Front

Back

Comments

Similar Pharmacy resources:

Other cards in this set

Card 2

Front

Back

Card 3

Front

Back

Card 4

Front

Back

Card 5

Front

Back

Comments

Related discussions on The Student Room

Similar Pharmacy resources: