Paediatric Dermatology

Question 1

Age range of eczema

Answer 1

Atopic eczema worse between ages 2-4
Worse pre-puberty (no sebum production to act as a barrier)
Tends to improve into teen years and beyond

Question 2

Distribution of atopic eczema in different age groups

Answer 2

Infants: cheeks often first affected
Toddlers: Extensor aspects of joints and genitals
School age on: flexural pattern

Question 3

Perioral dermatitis cause and treatment

Answer 3

typically occurs after beclamethasone, treatment is to stop using creams on the face +/- oral tetracyclines

Question 4

Management of eczema

Answer 4

Bathing: lukewarm watern, soap-free cleanser
Dilute K+ permangenate compresses for acute severe patch
Avoid wool
Emolliients after bathing
Topical steroids
Pimecrolis/tacrolimus for severe refractory eczema
Antihistamines may help reduce irritation, e.g. at night
Systemic steroids
MTX, AZA, phototyherapy for severe cases

Question 5

Steroid creams suitable for facial dermatitis

Answer 5

Hydrocortisone 0.5% or 1%
Suitable for face and other body parts with thin skin

Others are too strong

Question 6

Common causes of nappy rash

Answer 6

Usually a form of irritant contact dermatitis (due to bile salts and ammonium hydroxide in waste)
Other causes: candida, impetigo, seborrhoeic dermatitis etc.
NOT due to dermatophyte fungal infections (tinea)

Question 7

Management of nappy rash

Answer 7

Use disposable nappies over cloth
Gently clean with water and soft cloth
Pat dry gently, allow to air dry
Apply protective emollient ointment
give evening fluids early to reduce night time wetting
Observe if certain foods are related to rash (e.g. orange juice increasing stool acidity)
+/- mild topical steroid (e.g. hydrocortisone)

Question 8

Definition of acne vulgaris

Answer 8

Cutaneous disorder affecting adolescents and young adults involving hyperkeratisation, increased sebum production, infection and inflammation of the pilosebaceous follicles

Question 9

Predisposing and provoking factors of acne vulgaris

Answer 9

Family history
Stress
high BMI (in females)
PCOS
Meds: steroids, hormones, AEDs, EGFR inhibitors
Application of occlusive cosmetics (e.g. make up)
High environmental humidity
Diet high in dairy and high GI foods

Question 10

pathophysiology of acne vulgaris

Answer 10

increased proliferation and reduced desquamation of keratinocytes lining follicle - partial obstruction of follicle with sebum and keratin- inflammatory cells + sebum acts as growth medium for PROPIONIBACTERIUM ACNES - enzymes produced by bacterium promote degradation and rupture of follicular wall

Sebaceous glands are enlarged and sebum production increased by prepubertal levels of DHEA (androgens)

Question 11

Pathogen responsible for acne vulgaris

Answer 11

Propionibacterium acnes

Question 12

Management of acne

Answer 12

Investigate for hyperandrogenism in females (PCOS)
if Mild:
topical benxoyl peroxide (clearasil)
Low dose COCP
Antiseptic washes with salicylic acid
Light/laser therapy
MODERATE: as above plus
tetracycliness for 6 months (or erythromycin or trimethoprim if allergic)
Antiandrogen therapy: COCP, cyproterone acetate + ethinylesrtadiol and/or spironolactone
Isotretinoin (reduces sebum production, only use for 6-12m at a time)
SEVERE:
higher dose antibiotics, oral isotretinoin, referral to derm

Question 13

Bacteria responsible for impetigo

Answer 13

Strep pyogenes

Bullous impetigo: Staph aureus

Question 14

Common sites of impetigo

Answer 14

Exposed areas (hands and face) or in skin folds (esp. armpits)

Question 15

Appearance of impetigo

Answer 15

Round oozing patches of pustules enlarging every day
Clear blisters = bullous impetigo
May be golden yellow crusts

Question 16

Management of impetigo

Answer 16

Soak with water/whitevinegar mixture
Antiseptic ointment (betadine, hydrogen peroxide, chlorhexadine)
Oral fluclox 7 days
Cover affected areas,avoid close contact with others, stay home from school until crusts dried out, use separate towels and flannels, change ans wash clothes and linen daily

Question 17

Scalded skin syndrome definition

Answer 17

Red blistering skin that looks like a burn or a scald due to a staphylococcal infection of the skin and the release of epidermolytic toxins A and B

Question 18

Presentation of scalded skin syndrome

Answer 18

Begins with systemic symptoms: fever, irritability, widespread erythema
Rash develops within 24-48 hours
- tissue paper-like wrinkling of the skin followed by appearance of bullae
- particularly affects armpits, groin, orifices
- top layer of skin peels in sheets, leaving exposed moist, red tender area
- NIKIOLSKY SIGN PRESENT
May be painful and tender around infection site
May have associated weakness and dehydration
Confirm diagnosis with biopsy and bacterial culture

Question 19

Management of scalded skin syndrome

Answer 19

Hospitalisation
IV antibiotics (fluclox) = oral in several days if respond well
Supportive treatment (paracetamol, maintain fluid and electrolyte intake, skin care)
Usually heal completely within 5-7 days of starting treatment

Question 20

Copmlications of scalded skin syndrome

Answer 20

If untreated, or if treatment unsuccessful
Sepsis
Cellulitis
Pneumonia
Death in severe infection

Question 21

Scarlet fever definition

Answer 21

A bacterial illness with a distinctive rash of tiny pink-red spots covering the whole body in children who have recently had impetigo or a throat infection caused by strep pyogenes

Question 22

Age range and risk factors for scarlet fever

Answer 22

4-8y (older kids have developed antibodies against strep toxins, children under 2 still have maternal antibodies)
Risk factors:
- living in overcrowding
- close contact with someone who has a strep infection

Question 23

Clinical features of scarlet fever

Answer 23

1-4 day incubation
Sudden fever with:
sore throat, swollen neck glands, headache, nausea and vomiting, loss of appetite, strawberry tongue, abdominal pain, body aches, malaise
Characteristic rash (12-48 hours after onset of fever)
- starts below ears, neck, chest, armpits and groin - covers body over 24h
Scarlet spots - boiled lobster appearance
As progresses, looks like sunburn with goosebumps
Rough sandpaper like feel
Pastia lines
fever peaks by day 2 returns to normal in 5-7d
Rash starts to fade and peel like sunburn by day 6

Question 24

Cause of pastia lines

Answer 24

rupture of fragile blood vessels in skin folds

Occurs in scarlet fever

Question 25

Cause of scarlet fever

Answer 25

Group A strep (strep pyogenes) exotoxin

Question 26

Management of scarlet fever

Answer 26

Penicillin/amoxycillin for up to 10 days
ADDITIONAL:
Paracetamol PRN
Eating soft foods, drinking cool liquids
Oral antihistamines or calamine lotion for itch
Keep fingernails short

Question 27

Complications of scarlet fever

Answer 27

Rheumatic fever
Otitis media
Pneumonia
Septicaemia
Glomerulonephritis
Osteomyelitis
Death

Question 28

How contagious is chicken pox

Answer 28

> 90% to non-immune household contacts

Question 29

Management of alopecia areata

Answer 29

Steroid injections and creams

Question 30

Psoriasis treatment algorithm

Answer 30

1. Emollients, topical vitamin D, coal tar,
2. Topical steroids, retinoids or dithranol
3. Phototherapy
4. Oral MTX, retinoids, cyclosporin

Question 31

Type of skin condition that sometimes occurs as a sequel to strep throats

Answer 31

Guttate psoriasis