Paeds Derm

Question 1

What is the difference between Bullous Impetigo and SSSS?

Answer 1

Both caused by staph producing toxins, SSSS is generalised whereas impetigo is localised

Bullous impetigo may progress to SSSS if the infectious spreads haematogenously

Question 2

What is the difference on examination between SSSS and Staph/Strep toxic shock syndrome?

Answer 2

TSS does not have the perioral crusting on the face, no bullae or desquamation and it has a negative Nikolsky sign
Acral skin peeling/desquamation can occur but usually later in the disease and is much less severe

Question 3

What are the clinical features of the Scarlet Fever rash?

Answer 3

Sand-paper like rash with fine pinpoint papules that may be slightly erythematous&raquo_space; begins to desquamate

Nikolsky negative, rash not painful and the skin isn’t fragile

Question 4

What are the differentials for a bullous or desquamating rash?

Answer 4

Infections
- SSSS
- Late TSS
- Cutaenous candidiasis in neonates
- Bullous impetigo (localised)

Primary autoimmune
- TEN/SJS (meds)
- Pemphigus vulgaris and foliaceous

Post infection autoimmune
- Kawasaki Disease (localised blistering)
- Scarlett fever

Congenital
- epidermolysis bullosa
- epidermolysis ichthyosis

Trauma
- Burns

Question 5

What is the difference between Petechiae and Purpura?

Answer 5

Petechiae are non-blanching purple spots <2mm
Purpura are the same but >2mm

Question 6

What does petechiae in the distribution of the superior vena cava represent?

Answer 6

Less concerning as can occur spontaneously in the context of vomiting, coughing and significant crying
Make sure to check whole body
Purpura in the distribution of the vena cava are more concerning

Question 7

What is the dose of Clindamycin in Strep/Staph toxin diseases (ie SSSS)?

Answer 7

IV clindamycin 10mg/kg max 600mg QID

Question 8

What are the differentials for purpura?

Answer 8

Infectious
- Meningococcal, adenovirus, enterovirus, flu, disseminated sepsis

Mechanical
- NAI, coughing/straining/vomiting (above the nipples/SVC territory), local pressure (ie tourniquet)

Haematological
- DIC, ITP, leukaemia, HUS, aplastic anaemia

Immune
- HSP, vasculitis, drug induced thrombocytopaenia

Question 9

What is eczema herpeticum and how is it described?

Answer 9

Clinical
- A super infection of eczema with HSV 1/2
- Can predispose to further infections such as impetigo
- Vesicular monomorphic rash, may become confluent, surrounding erythema, may have erosions and crusting of lesions
- Typically found on the face, but can occur anywhere with active eczema

Investigation
- Viral swabs for HSV PCR
- Bacterial swabs for M/C/S

Treatment
- Aciclovir 10mg/kg IV if well, 20mg/kg if unwell
- Consider Flucloxacillin/Vancomycin if suspect Staph/strep superinfection

Complications
- Herpes encephalitis
- HSV hepatitis/opthalmicus
- Sepsis/bacteraemia
- DIC/ARDS/Death

Question 10

What is the most common cause of vaginal irritation in pre-pubertal girls? How is it treated?

Answer 10

Vulvovaginitis
- Pre-pubertal vaginal skin is thin and easily irritated
- Moisture, tight clothing, skin irritants and obesity can cause it
- Threadworms are an infectious cause

Exam findings
- Vulval erythema/swelling
- Minimal discharge
- Malodorous
- Adherent labia
- No other signs of trauma etc

Treatment
- Loose cotton underwear
- Avoid tight clothes
- Lose weight if obese
- Use minimal soap in bath/shower, dont use bubble bath or antiseptics
- Vinegar baths help
- Nappy rash cream helps

Question 11

What are the differentials for vulvovaginal disorders in pre-pubertal girls?

Answer 11

• Vulvovaginitis 1
• Vaginal FB
• STI/NAI
• HSV (STI or accidental innoculation)
• Threadworm/Pinworm
• Apthous ulcers (Lipschutz ulcer)
• Inflammatory conditions (Behcetz, Crohns diesease)
• Warts
• Lichen sclerosis
• Birth defects (haemangiomas, urogenital abnormalities)
• SJS/TEN
• Tumours (sarcoma Botryoides)

Question 12

When needing to perform a genital exam on a child, how should this be approached?

Answer 12