Dermatology

Question 1

Common causes nappy rash

Answer 1

Irritant (contact) dermatitis: most common, ^ if nappies not changed freq enough/ if infant has diarrhoea
Infantile seborrhoeic dermatitis
Candida infection
Atopic eczema

Question 2

Characteristics IRRITANT DERMATITIS nappy rash

Answer 2

Rash over convex surfaces of buttocks, perineal region, lower abdo and top of thighs.
Characteristically flexures spared (differentiates it from other causes nappy rash)
Rash erythematous, may have erosions + ulcers if severe

Question 3

Tx IRRITANT DERMATITIS nappy rash

Answer 3

Mild: emollient
Severe: mild topical corticosteroids

Question 4

Characteristics CANDIDA nappy rash

Answer 4

Erythematous
Includes skin flexures
May have satellite lesions

Question 5

Tx CANDIDA nappy rash

Answer 5

Topical antifungal

Question 6

Infantile seborrhoeic dermatitis clin features

Answer 6

Starts on scalp as erythematous scaly lesion forming yellow layer
Scaly rash can then extend to face, behind ears and then flexures and nappy area
NOT itchy (unlike atopic dermatitis)
Increased risk baby going on to develop contact dermatitis

Question 7

Infantile seborrhoeic dermatitis tx

Answer 7

Responds to emollients
Scalp: low conc salicylic acid + sulphur-containing ointment
If widespread on body: mild topical corticosteroid +/- antibacterial/ antifungal agents

Question 8

Scabies definition

Answer 8

Infestation with 8-legged mite Sarcoptes scabei, burrows down epidermis

Question 9

Scabies clinical features

Answer 9

Severe itching, worse in warm conditions + at night
Infants + young kids: palms, soles and trunk
Older kids: burrows, papules and vesicles between fingers + toes, axillae, flexor aspect of wrists, belt line, nipple line, penis + buttocks

Question 10

Dx scabies

Answer 10

Clin dx
History of itching
Characteristic lesions
Confirmation can be made by microscopy of skin scrapings from lesions (mite, eggs, mite faeces)

Question 11

Complications scabies

Answer 11

2y eczematous/ urticarial reactions

2y bacterial infection

Question 12

Tx scabies

Answer 12

Tx child + WHOLE FAMILY
Permethrin (insecticide) cream below neck, wash off after 8-12h
Benzoate emulsion below neck only
Malathoin lotion

Question 13

Head lice definition

Answer 13

Pediculosis capitis = head lice infestation

Question 14

Presentation pediculosis

Answer 14

Itching of scalp/ nape
Live lice on scalp
Nits (empty egg shells) on hairs 
\+/- 2y bacterial infection (often over nape of neck, can be confused w impetigo)
\+/- suboccipital lymphadenopathy

Question 15

Tx pediculosis

Answer 15

0.5% malathion-containing solution applied to hair, left overnight. Shampoo hair, remove lice and nits with fine-tooth comb. Repeat 1 week later OR
Permethrin cream rinse - leave on for 10 mins only OR
Wet combing every 3-4 days for 2 wks

Question 16

Causes erythema multiforme (HOMID)

Answer 16

Herpes simplex infection
Mycoplasma pneumoniae infection
Other infection
Drug reaction 
Idiopathic

Question 17

Erythema multiforme rash

Answer 17

Target lesions, central papule surrounded by erythematous ring. Lesions may also be vesicular/ bulllous

Question 18

Impetigo definition

Answer 18

Localised, highly contagious, staph aureus and/ or strep pyogenes (group A strep) infection
V CONTAGIOUS

Question 19

RFs impetigo

Answer 19

Pre-existing skin disease e.g. atopic eczema
Infants
Young children

Question 20

Impetigo lesions

Answer 20

Lesions on face, neck and hands
Begin as erythematous macules
Can become vesicular/ pustular/ bullous
Characteristic honey-coloured crusted lesions (due to rupture of vesicles with exudation of fluid)

Question 21

Spread of impetigo

Answer 21

Autoinoculation of infected exudate -> infection of other parts of the body 
Nasal carriage (between people)

Question 22

Mx impetigo

Answer 22

Mild cases: topical antibiotics e.g. mupirocin
Mod-severe: narrow-spectrum systemic abx, e.g. fluclox
OR broad-spectrum e.g. co-amox
Avoid nursery/ school until lesions dry
Nasal cream containing mupirocin/ chlorhexidene/ neomycin

Question 23

Bullous impetigo

Answer 23

Uncommon but potentially serious blistering form of impetigo, caused most commonly by Staph aureus

Question 24

Epidemiology bullous impetigo

Answer 24

Seen particularly in newborn

Question 25

Tx bullous impetigo

Answer 25

Systemic abx e.g. co-amoxiclav

Question 26

Onset and resulution atopic eczema

Answer 26

Usually in 1st year of life, 80% cases present before age 5 Uncommon in 1st 2 months (unlike infant seborrhoeic dermatitis) Mainly disease of childhood: 50% resolve by age 12, 75% by age 16

Question 27

Prevalence atopic eczema in UK

Answer 27

~20% | Prevalence increasing

Question 28

Definition atopic eczema (atopic dermatitis)

Answer 28

Chronic, relapsing inflammatory skin condition characterised by itchy red rash that favours skin flexures e.g. in creases of elbows, behind knees

Question 29

Predisposing factors eczema

Answer 29

FHx atopic disorders: eczema, asthma, alleric rhinitis | PMHx atopic disorders e.g. asthma

Question 30

Dx atopic eczema

Answer 30

Clinical dx If tested, most kids have ^ IgE level If hx suggests particular allergic cause, skin-prick and radioallergosorbent tests (RAST) Exclude immune def disorder if severe/ atypical

Question 31

Clin features atopic eczema

Answer 31

Itching = main symptom Itching -> scratching and exacerbation of the rash Scratched areas become erythematous, weeping and crusted Atopic skin usually dry, prolonged scratching can -> lichenification

Question 32

Distribution eczema rash

Answer 32

Infant >2 months: mainly face, also trunk | Older child: mainly flexor and friction surfaces

Question 33

Complications eczema

Answer 33

2y infection: usually Staph/ Strep - Herpes simplex: less common, but potentially v serious as can extend rapidly -> extensive vesicular reaction (eczema herpeticum) Regional lymphadenopathy

Question 34

Mx eczema

Answer 34

Avoid soap/ biological detergents, cotton clothing Avoid any known allergens, e.g. cows milk Emollients, >=2x day, and after baths Mild steroids (e.g. 1% hydrocortisone) 2x day if needed Stronger steroids: acute exacerbations, keep use to minimum

Question 35

Mx severe eczema

Answer 35

Immunomodulators e.g. tacrolimus, pimecrolimus: if child >2, not responding to corticosteroids, can use in ST Occlusive bandages: helpful if scratching and lichenification problems. Apply overnight

Question 36

Definition of squint (stabismus)

Answer 36

Misalignment of the visual axes, often reported by parents as misalignment of the eyes

Question 37

Non-pathological squint

Answer 37

Newborns usually have transient misalignments up to 3 months old

Question 38

Ix infant with squint

Answer 38

Check red reflexes | Refer for specialist ophthalmological opinion if >3 months

Question 39

Classification of squints

Answer 39

1) Concomitant (non-paralytic, common) | 2) Paralytic (rare) squint varies with gaze direction (due to paralysis of motor nerves)

Question 40

Causes non-paralytic squints

Answer 40

Usually due to refractive error in 1 or both eyes | Especially common in children with neurodevelopmental delay

Question 41

Tx non-paralytic squints

Answer 41

Often treated by correction with glasses | May need surgery

Question 42

Types non-paralytic squints

Answer 42

Squinting eye turns in = convergent (most common) Eye turns out = divergent Vertical misalignment

Question 43

Causes paralytic squint

Answer 43

Paralysis of motor nerves | Can be sinister: SOL, tumour

Question 44

Corneal light reflex test

Answer 44

Used to detect squints Pen-torch held at distance to produce reflections on both corneas simultaneously Light reflection should appear on both corneas simultaneously If doesn't -> squint

Question 45

Cover test

Answer 45

Test to determine presence, type and amount of ocular misalignment When a squint present and the fixing eye covered, the squinting eye moves to take up fixation Perform with object (e.g. toy) near and far away (some squints only present at 1 distance)