Dermatology

Question 1

What is the pathology for eczema?

Answer 1

Defect in filaggrin gene, allows transepidermal water loss and penetration of irritants.

Question 2

How does eczema present?

Answer 2

Itchy, dry, scaly erythematous patches on flexor surfaces (face and extensor surfaces in infants)
Papular and vesicular

Question 3

What is the complication of continuously scratching eczema?

Answer 3

Lichenification

Question 4

What are the management options of eczema?

Answer 4

Emollients
Topical steroids eg hydrocortisone
Topical immunomodulators eg tacrolimus
Non-sedating antihistamine eg cetirizine
Oral Prednisolone
Antiobiotics/antivirals if infected

Question 5

What is the pathology for psoriasis?

Answer 5

Hyperproliferation of keratinocytes and inflammatory cell infiltration

Question 6

How does psoriasis most commonly present in adolescence?

Answer 6

Sudden onset guttate psoriasis following streptococcal infection

Question 7

What is Auspitz sign?

Answer 7

Gentle removal of psoriatic scale resulting in capillary bleeding

Question 8

Different types of psoriasis?

Answer 8

Guttate
Chronic plaque (most common)
Seborrhoeic
Flexural
Pustular
Erythrodermic

Question 9

How does psoriasis present?

Answer 9

Well-demarcated erythematous scale patches on extensor surfaces and scalp
Burning, itching, painful

Question 10

Features of psoriasis other than plaques?

Answer 10

Nail changes eg pitting, onycholysis

Psoriatic arthropathy

Question 11

Types of topical treatments for psoriasis?

Answer 11

Vitamin D analogues
Corticosteroids
Coal tar preparations
Dithranol
Retinoids
Keratolytics

Question 12

3 functions of the skin

Answer 12

Regulation - temperature and fluid balance
Sensation
Protection - first defensive barrier to infection

Question 13

4 stages of wound healing process

Answer 13

Haemostasis
Inflammatory
Proliferative
Remodelling

Question 14

5 layers of epidermis

Answer 14

Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale

Question 15

3 zones of burn in Jackson’s model

Answer 15

Coagulation zone
Zone of stasis
Zone of hyperaemia

Question 16

What is lichee planus?

Answer 16

T cell mediated autoimmune disorder in which inflammatory cells attack an unknown protein within the skin and mucosal keratinocytes

Question 17

Which virus is lichen planus associated with?

Answer 17

Hepatitis B + C

Question 18

Where does lichen planus usually affect?

Answer 18

Flexor surfaces typically wrists and ankles

Sites of trauma

Question 19

What does lichen planus look like?

Answer 19

Violaceous, polygonal papules which join together to form plaques
(5 P’s: purple, pruritic, poly-angular, planar, papules)
Overlying white scales

Question 20

What are the white scales in lichen planus called?

Answer 20

Wickham’s striae

Question 21

How is lichen planus treated?

Answer 21

High potency topical steroids

Question 22

What systemic treatments are there for lichen planus?

Answer 22

Corticosteroids
Ciclosporin
Retinoids

Question 23

Which cells are responsible for histamine release in urticaria?

Answer 23

Mast cells and circulating basophils

Question 24

Risk factors for scabies

Answer 24

Overcrowding
Refugee camps
Hospitals
Prisons
Poverty
Immunosupressed/immunodeficient patients

Question 25

How long after infestation of mite does itch present with scabies?

Answer 25

4-6 weeks

Question 26

Sign of scabies

Answer 26

Burrows in tracks

Question 27

Treatment of scabies

Answer 27

Topical insecticide eg ivermectin (repeat after 8-10 days)

Question 28

Complication of scabies

Answer 28

Secondary staph infection

Question 29

Categories for systemic causes of itch

Answer 29

``` Cholestasis Endocrine Haematological Chronic renal failure Miscellanous ```

Question 30

What are the cholestatic causes of itch?

Answer 30

PBC Extrahepatic obstruction eg gallstones, sclerosing cholangitis Obstetric cholestasis Drugs eg opiates, COCP

Question 31

Name 4 endocrine causes of itch

Answer 31

Thyrotoxicosis Hyperparathyroidism Myxoedema Diabetes

Question 32

Name 4 haematological causes of itch

Answer 32

Hodgkin's lymphoma Iron deficiency Polycythaemia Multiple myeloma

Question 33

Name a non-haematological malignant cause of itch

Answer 33

Bronchial carcinoma

Question 34

What is erythema nodosum?

Answer 34

Inflammation of fat cells under the skin. Hypersensitivity response to a variety of causes eg Group A beta haemolytic strep, primary tuberculosis, , IBD, chlamydia, leprosy. Red tender nodules that last a few weeks and should resolve within a month.

Question 35

What is koebner phenomenon and which conditions can it be seen in?

Answer 35

Appearance of new skin lesions in areas of cutaneous injury, usually caused by scratching in otherwise healthy skin. Occurs mostly in psoriasis, vitiligo and lichen planus.

Question 36

``` Order the following topical steroids according to potency: Betnovate Dermovate Eumovate Hydrocortisone 1% ```

Answer 36

Mild potency: Hydrocortisone 1% Moderate potency: Eumovate Potent: Betnovate Very Potent: Dermovate

Question 37

What is angular cheilitis and what condition is it associated with?

Answer 37

A contact irritant dermatitis due to dribbling of saliva, with secondary proliferation of bacteria or candida. Associated with crohn's disease.

Question 38

What is the definition of cellulitis and what organism is it commonly caused by?

Answer 38

spreading of inflammation in subcutaneous tissue, most commonly caused by streptococcus pyogenes.

Question 39

What is a complication of lichen sclerosis

Answer 39

Oral squamous cell carcinoma

Question 40

What is dermatitis herpetiformis?

Answer 40

Autoimmune blistering skin condition associated with coeliac disease

Question 41

Who is most likely to be affected by dermatitis herpetiformis?

Answer 41

White people Males 20s and 30s

Question 42

How does dermatitis herpetiformis present?

Answer 42

Itchy bullies rash on extensor surfaces eg buttocks, scalp, knees and elbows

Question 43

What investigations would you do for herpetiformis?

Answer 43

Skin biopsy - IgA deposition Anti tissue transglutaminase antibodies IgA endomysial antibodies

Question 44

What is seen on immunofluorescence assay in lichen planus?

Answer 44

IgM deposition

Question 45

What does histology show for lichen planus?

Answer 45

Saw tooth pattern of epidermal hyperplasia | Lymphocytic infiltration

Question 46

What is actinic keratosis?

Answer 46

Thickened scaly skin due to long term sun exposure, UV induced.

Question 47

How is actinic keratosis treated?

Answer 47

5-fluorouracil

Question 48

Complication of actinic keratosis

Answer 48

SCC

Question 49

How is head lice treated?

Answer 49

Dimeticone 4% gel

Question 50

What is gingival hyperplasia and what does it indicate?

Answer 50

Gum overgrowth - can be caused by CCB

Question 51

What is telogen effluvium?

Answer 51

Diffuse hair loss triggered by stress, bereavement, childbirth. Resolves spontaneously within 100 days

Question 52

What is erythrodermic psoriasis?

Answer 52

Dermatological emergency Hypotension, tachycardia, borderline pyrexia Requires hospital admission

Question 53

What skin condition is associated with DM?

Answer 53

Necrobiosis lipoidica diabeticorum

Question 54

Difference in appearance of lichen planus and lichen sclerosus?

Answer 54

Lichen planus - Purple, polygonal, papular, pruritic | Lichen sclerosus - white polygonal papules, forms plaques, itch, dyspareunia, perianal fissures