Derm

Question 1

Acne classification

Answer 1

mild: open and closed comedones with or without sparse inflammatory lesions

moderate acne: widespread non-inflammatory lesions and numerous papules and pustules

severe acne: extensive inflammatory lesions, which may include nodules, pitting, and scarring

Question 2

acne mx

Answer 2

mild to moderate
- 1st line: 12-week course of topical combination therapy (adapalene & benzoyl peroxide / tretinoin & clindamycin / benzoyl peroxide & clindamycin )
- only benzoyl peroxide if pt wants to avoid others/ CI

moderate to severe
- 12wks: first 2 combinations above OR oral lymecycline/ doxycycline with topical adapalene/ benzoyl peroxide/ azelaic acid
- COCP are alternative to oral abx in women - like abx, should be used w topical.
- Dianette (co-cyprindiol) used as 2nd line - has anti-androgen effects. Increases VTE compared to other COCP

Oral isotretinoin: only under specialist supervision

IMPORTANT
- pregnancy is a contraindication to topical and oral retinoid treatment
- oral tetracyclines avoided in pregnant & breastfeeding & <12yrs. oral erythromycin used in pregnancy instead
- oral antibiotics needs to be co-prescibed with another topical therapy - but not topical abx!!

Question 3

acne referral should be considered in the following scenarios:

Answer 3

mild to moderate acne has not responded to two completed courses of treatment

moderate to severe acne has not responded to previous treatment that includes an oral antibiotic

acne with scarring

acne with persistent pigmentary changes

acne is causing or contributing to persistent psychological distress or a mental health disorder

Question 4

Actinic keratoses mx

Answer 4

prevention of further risk: e.g. sun avoidance, sun cream

fluorouracil cream: typically a 2 to 3 week course

topical diclofenac: may be used for mild AKs. Moderate efficacy but much fewer side-effects

topical imiquimod

cryotherapy

curettage and cautery

Question 5

antihistamins classification, examples & receptor

Answer 5

H1 inhibitors

Examples of sedating antihistamines:
chlorpheniramine
(have sedating & antimuscarinic SEs)

Examples of non-sedating antihistamines
loratidine
cetirizine

Question 6

Athlete’s foot cause & mx

Answer 6

tinea pedis.

fungi in the genus Trichophyton.

topical imidazole, undecenoate, or terbinafine first-line

Question 7

Bowen disease

Answer 7

1st line = topical 5-fluorouracil

cryotherapy
excision

Question 8

Bullus pemphigoid vs pemphigus vulgaris

Answer 8

both autoimmune

Bullus pemphigoid
- sub-epidermal blistering, typically around flexures
- against hemidesmosomal proteins BP180 and BP230.
- no mucosal involvement
- immunofluorescence shows IgG and C3 at the dermoepidermal junction

Pemphigus vulgaris
- abs against desmoglein 3, a cadherin-type epithelial cell adhesion molecule
- mucosal ulceration is common & first px
- skin blistering- flaccid, easily ruptured vesicles and bullae
- Nikolsky’s sign

Question 9

what can you use to assess the extent of the burn

Answer 9

Wallace’s Rule of Nines: head + neck = 9%, each arm = 9%, each anterior part of leg = 9%, each posterior part of leg = 9%, anterior chest = 9%, posterior chest = 9%, anterior abdomen = 9%, posterior abdomen = 9%

Lund and Browder chart: the most accurate method

palmar surface is roughly equivalent to 1% of total body surface area (TBSA). Not accurate for burns > 15% TBSA

Question 10

depth of the burn px

Answer 10

1st degree - Superficial epidermal - Red and painful, dry, no blisters

2nd degree - Partial thickness (superficial dermal) - Pale pink, painful, blistered. Slow capillary refill

2nd degree - Partial thickness (deep dermal). Typically white but may have patches of non-blanching erythema. Reduced sensation, painful to deep pressure

Full thickness - Third degree- White (‘waxy’)/brown (‘leathery’)/black in colour, no blisters, no pain

Question 11

burns Referral to secondary care criteria?

Answer 11

superficial dermal burns of more than 3% TBSA in adults, or more than 2% TBSA in children

all deep dermal and full-thickness burns.

superficial dermal burns involving the face, hands, feet, perineum, genitalia, or any flexure

circumferential burns of the limbs, torso, or neck

any inhalation injury

any electrical or chemical burn injury

suspicion of non-accidental injury

Question 12

Dermatitis herpetiformis dx

Answer 12

skin biopsy: direct immunofluorescence shows deposition of IgA in a granular pattern in the upper dermis

Question 13

Eczema herpeticum mx

Answer 13

( primary infection of the skin by herpes simplex virus 1 or 2, usually in atopic eczema )

admitted for IV aciclovir.

Question 14

Causes of erythema multiform

Answer 14

viruses: herpes simplex virus (the most common cause), Orf
idiopathic
bacteria: Mycoplasma, Streptococcus
drugs: penicillin, sulphonamides, carbamazepine, allopurinol, NSAIDs, oral contraceptive pill, nevirapine
connective tissue disease e.g. Systemic lupus erythematosus
sarcoidosis
malignancy

erythema multiforme major is associated with mucosal involvement.

Question 15

Erythema nodosum causes

Answer 15

infection:
streptococci
tuberculosis
brucellosis

systemic disease:
sarcoidosis
inflammatory bowel disease
Behcet’s

malignancy/lymphoma

drugs:
penicillins
sulphonamides
combined oral contraceptive pill
pregnancy

Question 16

Erythrasma features

Answer 16

asymptomatic, flat, slightly scaly, pink or brown rash usually found in the groin or axillae.

overgrowth of the diphtheroid Corynebacterium minutissimum

Topical miconazole

Question 17

Fungal nail infection causes

Answer 17

dermatophytes
account for around 90% of cases
mainly Trichophyton rubrum

yeasts
account for around 5-10% of cases
e.g. Candida

non-dermatophyte moulds

Question 18

Fungal nail infection ix & mx

Answer 18

Ix - nail clippings +/- scrapings w microscopy & culture

mx
- if pt unbothered - leave it
- if dermatophyte or Candida infection is confirmed: topical amorolfine if limited; oral terbinafine if more extensive dermatophyte infection; oral itraconazole if more extensive Candida infection

Question 19

Hereditary haemorrhagic telangiectasia fx

Answer 19

autosomal dominant condition

Osler-Weber-Rendu syndrome

multiple telangiectasia over the skin and mucous membranes.

epistaxis : spontaneous, recurrent nosebleeds

telangiectases: multiple at characteristic sites (lips, oral cavity, fingers, nose)

visceral lesions: for example gastrointestinal telangiectasia (with or without bleeding), pulmonary arteriovenous malformations (AVM), hepatic AVM, cerebral AVM, spinal AVM

family history: a first-degree relative with HHT

Question 20

hirsutism & hypertrichosis mx

Answer 20

hirsutism- androgen-dependent hair growth
- weight loss if overweight
- cosmetic: waxing/bleaching
- COCP
- facial hirsutism: topical eflornithine - contraindicated in pregnancy and breast-feeding

hypertrichosis- androgen-independent

Question 21

Hyperhydrosis tx

Answer 21

topical aluminium chloride preparations are first-line.

(iontophoresis, botulinum toxin, surgery)

Question 22

Impetigo mx

Answer 22

1. hydrogen peroxide 1% cream for ‘people who are not systemically unwell or at a high risk of complications’
2. topical fusidic acid - topical mupirocin if resistance suspected

Extensive disease
oral flucloxacillin
oral erythromycin if penicillin-allergic

children should be excluded from school until the lesions are crusted and healed or 48 hours after commencing antibiotic treatment

Question 23

Keloid scars common sites & tx

Answer 23

(in order of decreasing frequency): sternum, shoulder, neck, face, extensor surface of limbs, trunk

more common in young people with dark skin

intra-lesional steroids
excision maybe

Question 24

main features of a melanoma

Answer 24

The main diagnostic features (major criteria):
Change in size
Change in shape
Change in colour

Secondary features (minor criteria)
Diameter >= 7mm
Inflammation
Oozing or bleeding
Altered sensation

Question 25

Pellagra? px?

Answer 25

nicotinic acid (niacin) deficiency. (B3) dermatitis, diarrhoea and dementia.depression may occur as a consequence of isoniazid therapy

Question 26

Periorificial dermatitis? cause? tx?

Answer 26

cause: Topical corticosteroids, and to a lesser extent, inhaled corticosteroids clustered erythematous papules, papulovesicles and papulopustules Management steroids may worsen symptoms should be treated with topical or oral antibiotics

Question 27

Pityriasis rosea features

Answer 27

acute, self-limiting rash- disappears after 6-12 weeks herpes hominis virus 7 (HHV-7) no prodrome, but a minority may give a history of a recent viral infection herald patch (usually on trunk) -> erythematous, oval, scaly patches; distribution parallel to the line of Langer -'fir-tree' appearance

Question 28

Pityriasis versicolor features, mx

Answer 28

also called tinea versicolor, Malassezia furfur patches may be hypopigmented, pink or brown (hence versicolor). Management - ketoconazole shampoo topical - if failure to respond, consider alternative diagnoses (e.g. send scrapings to confirm the diagnosis) + oral itraconazole

Question 29

factors which may exacerbate psoriasis?

Answer 29

BLANQ = white in french; white plaques of psoriasis beta blocker lithium alcohol, ACE Is nsaids quines (antimalarials -> chloroquine and hydroxychloroquine) Streptococcal infection may trigger guttate psoriasis. trauma

Question 30

Psoriasis mx

Answer 30

Plaque!! 1st: potent corticosteroid applied once daily plus vitamin D analogue for up to 4 weeks as initial treatment 2nd: if no improvement after 8 weeks - if no improvement after 8 weeks t 3rd - if no improvement after 8-12 weeks - potent corticosteroid applied twice daily for up to 4 weeks - OR coal tar preparation short-acting dithranol can also be used secondary care - Phototherapy - Systemic therapy: oral methotrexate, ciclosporin, retinoids, biologics Scalp !! - potent topical corticosteroids used once daily for 4 weeks Face, flexural and genital !! - mild or moderate potency corticosteroid applied once or twice daily for a maximum of 2 weeks IMPORTANT - 4-week break before starting another course of topical corticosteroids - potent corticosteroids for no longer than 8 weeks - Vitamin D analogues (calcipotriol), unlike corticosteroids they may be used long-term - should be avoided in pregnancy

Question 31

Pyoderma gangrenosum tx

Answer 31

oral steroids as first-line treatment

Question 32

Isotretinoin SEs

Answer 32

teratogenicity - two forms of contraception dry skin, eyes and lips/mouth (most common) low mood raised triglycerides hair thinning intracranial hypertension

Question 33

acne Rosacea mx

Answer 33

simple measures- sunscreen, camouflage predominant erythema/flushing, limited telangiectasia - topical brimonidine gel (alpha agonist) mild-to-moderate papules and/or pustules - topical ivermectin is first-line - topical metronidazole or topical azelaic acid moderate-to-severe papules and/or pustules - combination of topical ivermectin + oral doxycycline Referral for no improvement, rhinopehyma - laser therapy

Question 34

Scabies mx

Answer 34

mite Sarcoptes scabiei permethrin 5% is first-line- to all areas, including the face and scalp malathion 0.5% is second-line all household and close physical contacts should be treated at the same time, even if asymptomatic Crusted (Norwegian) scabies- Ivermectin

Question 35

Seborrhoeic dermatitis associated conditions

Answer 35

otitis externa and blepharitis may develop HIV Parkinson's disease

Question 36

Seborrhoeic dermatitis mx

Answer 36

Scalp 1st. ketoconazole 2% shampoo 2nd. over the counter preparations containing zinc pyrithione ('Head & Shoulders') and tar ('Neutrogena T/Gel') selenium sulphide and topical corticosteroid may also be useful Face and body management - topical antifungals: e.g. ketoconazole - topical steroids: best used for short periods

Question 37

Shingles mx

Answer 37

diagnosis is usually clinical remind patients they are potentially infectious until the vesicles have crusted over, usually 5-7 days following onset - avoid pregnant women and the immunosuppressed - cover lesions Analgesia - 1st. paracetamol and NSAIDs are first-line - 2nd. neuropathic agents (e.g. amitriptyline) - oral corticosteroids maybe - first 2 weeks in immunocompetent adults wlocalized shingles if the pain is severe and not responding to the above treatments Antivirals - within 72 hours for the majority of patients (reduced incidence of post-herpetic neuralgia)

Question 38

Skin manifestations of systemic lupus erythematosus (SLE)

Answer 38

photosensitive 'butterfly' rash discoid lupus alopecia livedo reticularis: net-like rash

Question 39

Spider naevi v telangiectasia

Answer 39

Spider naevi fill from the centre, telangiectasia from the edge .

Question 40

Stevens-Johnson syndrome causes

Answer 40

penicillin sulphonamides!! lamotrigine, carbamazepine, phenytoin allopurinol NSAIDs oral contraceptive pill ( target lesions, vesicles or bullae, Nikolsky sign, mucosal involvement)

Question 41

Tinea types & mx

Answer 41

dermatophyte fungal infections Tinea capitis (scalp ringworm) - most common cause is Trichophyton tonsurans - management (based on CKS guidelines): oral antifungals: terbinafine for Trichophyton tonsurans. griseofulvin for Microsporum infections. & ketoconazole shampoo Tinea corporis (ringworm) trunk, legs or arms - Trichophyton rubrum and Trichophyton verrucosum - oral fluconazole Tinea pedis (athlete's foot)

Question 42

Urticaria mx

Answer 42

non-sedating antihistamines (e.g. loratadine or cetirizine) are first-line - 6 wks a sedating antihistamine (e.g. chlorphenamine) - night time maybe prednisolone is used for severe or resistant episodes

Question 43

Vasculitides types

Answer 43

Large vessel - temporal arteritis - Takayasu's arteritis Medium vessel - polyarteritis nodosa - Kawasaki disease Small vessel ANCA-associated vasculitides - granulomatosis with polyangiitis (Wegener's granulomatosis) - eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome) - microscopic polyangiitis immune complex small-vessel vasculitis - Henoch-Schonlein purpura - Goodpasture's syndrome (anti-glomerular basement membrane disease) - cryoglobulinaemic vasculitis - hypocomplementemic urticarial vasculitis (anti-C1q vasculitis)