Medicine - Dermatology

Question 1

Describe a macule

Answer 1

<0.5cm flat area of discolouration

Question 2

Describe a patch

Answer 2

> 0.5cm flat area of discolouration

Question 3

Describe a papule

Answer 3

<0.5cm palpable lesion

Question 4

Describe a nodule

Answer 4

> 0.5cm palpable lesion

Question 5

Describe a vesicle

Answer 5

<0.5cm fluid filled lesion

Question 6

Describe a bullae

Answer 6

> 0.5cm fluid filled lesion

Question 7

Describe a pustule

Answer 7

<0.5cm small pus filled vesicular lesions

Question 8

Describe an abscess

Answer 8

> 0.5cm pus filled vesicular lesions

Question 9

Describe a plaque

Answer 9

raised, flat topped area often with surface discharge

Question 10

Describe toxic epidermal necrolysis (TEN)

Answer 10

A derm emergency
Drug induced blistering and skin detachment disorder
Ass. with fever and >10% body SA involved

Question 11

What can cause toxic epidermal necrolysis (TEN)

Answer 11

Drugs! - epilepsy drugs, allopurinol, NSAIDs

Question 12

How does TEN present?

Answer 12

• bullae

- Niklosky’s sign +ve (the epidermis sloughs easily when pressure is applied)

Question 13

How is TEN managed?

Answer 13

• stop offending drug

- supportive

Question 14

What is Stevens Johnson Syndrome?

Answer 14

same as TEN but <10% body SA involved

Question 15

What is erythema multiforme and its S/Sx

Answer 15

A derm emergency
hypersensitivity reaction associated with drugs/certain infections:
- HSV
- mycoplasma pneumoniae

Has classical target appearance
Mucosal-cutaneous involvement: therefore mucosal erosions and difficulty urinating

Question 16

How is erythema multiforme classified and treated?

Answer 16

EM minor = <10% body SA affected and no mucosal involvement
EM major = mucosal involvement

usually resolves by itself in 2-3 weeks, supportive treatment and antibiotics/antivirals depending on the cause

Question 17

What is acute urticaria and its causes

Answer 17

A derm emergency
Itchy wheals, oedema and erythema
acute (<6 weeks)
mainly due to FOOD/DRUG allergic reactions, but also viral/bacterial infections or vaccinations

Question 18

How is acute urticaria managed and what complication can arise?

Answer 18

Antihistamines
Steroids
Immunosuppression

Complication = anaphylactic shock!

Question 19

What is erythroderma and its causes

Answer 19

A derm emergency
intense widespread reddening of the skin
Normally associated with other skin conditions - dermatitis, psoriasis

Question 20

What are S/Sx of erythroderma

Answer 20

warm, itchy scaly skin
Nail thickening
serous oozing
generalised lymphadenopathy

Question 21

How is erythroderma treated and what complications can arise

Answer 21

Emollients
Topical steroids
Antibiotics
Antihistamines

Complications:
dehydration/electrolyte imbalances
hypothermia
hypoalbuminaemia = oedema
secondary skin infections

Question 22

Describe cellulitis and its RFx

Answer 22

Acute spreading dermal infection

RFx: PVD, DM, skin breaks, oedema, DVT, eczema

Question 23

What are cellulitis S/Sx

Answer 23

erythema
oedema
warmth
tenderness
discomfort
disruption of the cutaneous barrier

Question 24

How is cellulitis investigated?

Answer 24

Hx and Ex
Bloods
Blood cultures
Skin biopsy
MRI (?nec fasc), X-ray (?osteomyelitis)

Question 25

What classification system is used for cellulitis

Answer 25

Enron classification

Question 26

How is cellulitis treated?

Answer 26

``` Moderate = IV flucloxacillin Severe = IV Flucloxacillin, Clindamycin, Gentamycin ```

Question 27

Describe necrotising fasciitis and its RFx

Answer 27

life threatening soft tissue infection rapidly progressive and pain out of proportion - IVDU, immunosuppression, hospitalisation, skin lesions, VSV infection

Question 28

What are the two types of nec fasc?

Answer 28

Type 1 - polymicrobial (in existing wounds) | Type 2 - group A strep only (in previously healthy tissue, usually strep pyogenes)

Question 29

What antibiotics are used to treat nec fasc?

Answer 29

``` IV: fat must be clinically gross flucloxacillin metronidazole benzylpen clindamycin gent ```

Question 30

Describe impetigo and its cause

Answer 30

golden crusty skin lesions, contagious, common in children - caused by staph aureus usually mild and self-limiting

Question 31

What is tinea and how is it diagnosed/treated?

Answer 31

Superficial fungal infection of skin (ring worm, athletes foot) or nails Diagnose with skin scrapings and treat with antifungal creams (-azoles)

Question 32

What is pityriasis rosea?

Answer 32

Common rash in young adults, cause unclear may be prodromal cold symptoms usually herald patch and then christmas tree rash usually self resolving but may need anti-itch and steroid creams

Question 33

Describe vitiligo hypopigmentation

Answer 33

an acquired pigmentation disorder, usually symmetrical | immune destruction of melanocytes = less melanin

Question 34

Describe eczema (dermatitis) and its various subtypes

Answer 34

Itchy, dry, sore red skin - atopic: linked to allergy - seborrheic: over skin with sebacious glands - discoid: circular patches - varicose: gravitational - contact: delayed T4 hypersensitivity reaction - pompholyx: restricted to hands/feet

Question 35

What is the pathophys behind dermatitis and its presentation?

Answer 35

abnormal filaggrin expression, impaired skin barrier function, increased exposure to foreign antigens, triggers immune mediated response S/Sx: - vesicles and papules - pruritis - xerosis - flexural involvement!!!!!! - erythema - scaling

Question 36

How is dermatitis treated?

Answer 36

``` emollients topical steroids oral Abx antihistamines immunosuppression UV light therapy ```

Question 37

Describe psoriasis and its subtypes

Answer 37

Chronic immune mediated inflammatory condition 20% pts get arthritis Types: - plaque - guttate -> tear shaped, after strep throat infection! - pustular - erythrodermic - flexural/inverse -> in genitals/skin folds - koebner phenomenon -> develops on healthy skin at site of cutaneous injury - palmar/plantar pustulosis

Question 38

Describe the pathophysiology of psoriasis

Answer 38

Hyperproliferation -> increased turnover of skin cells and release of pro-inflammatory cytokines Certain drugs can predispose: lithium, B blockers

Question 39

What are the S/Sx of psoriasis?

Answer 39

``` Itching Burning Silvery, scaly plaques with a pinky salmon base Nail changes (pitting, onycholysis) Auspitz sign ```

Question 40

What is the management of psoriasis

Answer 40

``` Moisturisers Topical steroids Vit D analogue/phototherapy Immunosuppression Oral retinoid Coal tar Dithranol ```

Question 41

Describe acne vulgaris and its subtypes

Answer 41

Skin disease affecting the sebacious glands types: - vulgaris (papulopustular, nodulocystic, comedonal) - fulminans (sudden onset and systemic upset) - rosacea - inversus (in groin/axilla/nasal cleft) - agminate (in middle aged/adult patients)

Question 42

Describe the pathophys of acne vulgaris

Answer 42

Multifactorial XS androgens in puberty Keratinocytes do not shed properly and clog pores Pores infected with propionibacterium acnes

Question 43

What are the treatments for acne?

Answer 43

``` Salicylic acid Topical benzylperoxide Topical Abx and retinoid Oral Abx/retinoid/corticosteroidd Oral isotretinoin! ```

Question 44

Describe rosacea, its causes and presentation:

Answer 44

Chronic skin condition characterised by redness, telangectasia, roughened skin and general inflammation - cause unclear but triggers: climatic exposures, drugs... Presents: redness, flushing, telangectasia, watery/irritated eyes, rhinophyma

Question 45

Describe the two autoimmune blistering skin conditions, their causes, the differences between them and how they are treated

Answer 45

Bullous pemphigoiD = deep blister Bullous pemphiguS = superficial blister Due to autoimmune attack of the epidermal-dermal junction Mainly affects older pts with neurological conditions! (PD, epilepsy, stroke, MS, ALS) Presents with tense erosions and blister which are Nikolsky sign -ve Treated with topical/oral steroids depending severity, anti-inflammatory medications, immunosuppression

Question 46

What cell type is malignant in BCC?

Answer 46

Basal cells Rarely metastasises/kills

Question 47

What cell type is malignant in SCC?

Answer 47

Keratinocytes Increased risk of mets and death

Question 48

What cell type is malignant in melanoma?

Answer 48

Melanocytes?

Question 49

What is Breslow thickness?

Answer 49

Breslow thickness = determines the excision margin - melanoma in situ =5mm margin - <1mm = 1cm - 1-4mm = 1-2cm - >4mm = >2cm

Question 50

What questions are important to ask about a skin lesions?

Answer 50

``` A-E assymetry border colour changes diameter enlarging/evolving ```

Question 51

Describe the cause of alopecia and its types

Answer 51

Autoimmune attack of hair follicles by inflammatory CD4+ T cells causing hair loss Scarring type (irreversible hair loss) - discoid lupus - syphilis - scalp cellulitis - tinea Non-scarring (reversible hair loss) - alopecia areata - alopecia totalis (all head) - alopecia universalis (all body)

Question 52

What are the S/Sx of alopecia areata

Answer 52

``` well circumscribed areas Hair pull test +ve small white hair growth Exclamation hairs Psychological effects: - anxiety - depression - isolation ```

Question 53

What is livedo reticularis and in what conditions would you see it?

Answer 53

mottled red/blue non-blanching skin lesions, associated with RA/SLE/PAN

Question 54

What is acanthosis nigricans and what is it associated with?

Answer 54

Benign, smooth, hyperketotic plaques in intertriginous areas | Seen in DM

Question 55

What is pyoderma gangrenosum and in what conditions is it seen?

Answer 55

Enlarging painful ulcers with purple overhanging edge Seen in: IBD, RA, myeloma, leukaemia

Question 56

What is erythema nodosum and in what conditions is it seen?

Answer 56

Erythematous tender nodules over shins | Associated with IBD/TB/Sarcoidosis

Question 57

In what conditions is erythema multiforme associated with?

Answer 57

Mycoplasmae pneumoniae, HSV