Paeds Rashes
Kawasaki
disease
Epidemiology: infants and children effected; 85% <5yrs, 30% <1yr; peak occurrence 18-24/12; most common cause
of acquired paediatric heart disease; incr in Asian / Blacks; 9-20:100,000
medium sized vessels (inc. coronary, renal, hepatic,
Pathophysiology: Generalised systemic vasculitis of
splanchnic) of unknown cause (likely post-infectious, due to super Ag bacterial toxins)
Diagnostic Criteria
1) Fever >5 days (abrupt onset; in 100%)
2) 4 out of 5 of following within 3/7 of rash: can have <4 if echo shows
CAD; those <6m old may have incomplete presentation (2-3 criteria)
a. Bilat non-exudative bulbar conjunctival injection (with
perilimbic sparing) – present in 80%
b. Pharyngeal oedema / red cracked lips / strawberry tongue
– present in 90%; lasts 2-3/52; dry, crack and fissure by 6/7
c.
d.
e.
Cervical lymphadenopathy – present in 60-98%;
usually solitary, unilateral, >1.5cm
Diffuse erythema and swelling of hands and feet during
acute phase (predilection for perineum, usually
accompanies onset of fever; erythema, oedema) 
periungal desquamation during convalescent phase (after 23/52); present in 85-95%
Polymorphous generalized rash – present in 99%
May also get arthritis (35%), hepatitis (40%), AP, D+V, urethritis is sterile
pyuria (70%), asceptic meningitis (25%), pericardial effusion / arrhythmia
(20%), gallbladder hydrops (<10%), carditis and CCF (<5%; usually resolves by
6-8/52)
Phases:
Acute febrile phase: weeks 0 - 2; myocarditis (25%; resolves alone), pericarditis (resolves alone), pericardial effusion
(rarely large), valvular dysfunction, LV dysfunction (50%), arrhythmias; MI (1%); conduction defects (20%); coronary
arteritis begins
Subacute phase: weeks 2 -3
Convalescent phase: weeks 4 - 6
Symptoms: fever for 1-2/52; tachycardia out of proportion to fever, gallop rhythm
Ix: ECG: non-specific ST-T waves changes (in 7%)
CXR
bloods (anaemia for age, decr alb, incr plt, incr WBC, incr ALT, incr ESR and CRP ++, decr alb), ASOT / anti-DNAase B
urine (sterile pyuria)
echo (perform at initial presentation  at 2/52  at 6/52  at 1yr; may not need to do initial echo if present
<10/7 with normal ECG)
Complications: Coronary artery aneurysms (20% untreated children) occur in 2nd – 4th week (can be as early as 3/7 or
be delayed 6-8/52; RF for development: male, <1yr, >5yrs, fever >10/7, decr alb / Hb, clinical signs of cardiac
involvement); stenosis, thrombosis; MI is leading cause of death; 75% fatalities occur within 6/52; children <6/12 at
incr risk of developing cardiac complications so have lower threshold for diagnosis in this group; mortality <1%;
excellent prognosis if trt within 10/7 and normal echo
Treatment: Supportive care
IVIG 2g/kg over 12hrs  symptomatic improvement in 90%, prevents aneurysm in 95% (decr risk of heart
Scarlet
Fever
abnormality from 20% to 3-5% if given in 1st 10/7); if ongoing fever, may require 2nd dose; aim to commence early than
D5
High dose aspirin 30-50mg/kg/day until fever gone  3-5mg/kg OD for 6-8/52  helps prevent thrombosis; no
evidence that it prevents the formation of aneurysms; must continue on low dose therapy indefinitely if develop
aneurysms, otherwise stop at 6/52
Corticosteroids if refractory to above treatment
Cause: Group A beta-haemolytic strep  erythrogenic toxin
Incubation: 2-4/7 (ie. Short)
Sx: Acute onset fever, sore throat, headache, V, AP  exanthem develops over 1-2/7
Red tonsils and pharynx covered in exudates
Tongue white coating through which red hyptertrophied papillae project (white strawberry tongue)  white
coating disappears after 4-5/7  red strawberry tongue
Bright red / haemorrhagic spots on soft palate.
After 12-48hrs  Red, finely punctate 1-2mm blanching papules (rough sandpaper) on neck, axillae and groin 
Rapidly spreads to trunk and extremities. Linear petechial eruptions in antecubital and axillary folds (Pastia’s lines).
Fades at 6/7. Desquamates at 2/52, on hands and feet 1st.
Facial flushing and circumoral pallor.
Complications: OM, sinusitis, rheumatic fever, post-strep GN
Ix: ASOT, swab
Trt: Penicillin 10/7
Measles
Cause: RNA myxovirus
Epidemiology: rare in immunised; now mostly seen in older patients; highly
infectious (90% susceptible close contacts will become infected)
Incubation: 7-18/7 (av 10/7); 14/7 between exposure and rash; patient
infectious from 5/7 before rash to 4/7 after rash
Case definition: 3-4/7 URTI  rash
1. Fever >38 (ie. High)
2. Rash: fever always present at time of onset of rash; behind ears and
at hairline  spreads from head to feet, inc palms and soles;
erythematous maculopapular, red blanching  confluence esp on
face  copper-brownish hue as resolves  desquamates
after 3/7; lasts 1/52
3. 1 of cough / coryza / conjunctivitis / Koplick spots (white,
bluish-white 1mm spots with red base on buccal mucosa; appear 1/7
before rash); may have generalised lymphadenopathy; may be
diarrhoea
Complications: OM (2.5%), pneumonia (4%; responsible for 50% deaths); encephalitis (0.1%; onset 1-2/52
after disease; mortality 10-15%; permanent neuro damage in 40%); subacute sclerosing panencephalitis (can occur 410yrs later, progressive mental deterioration and death); myocarditis, nephritis, hepatitis, pericarditis, keratitis
Ix: swab for PCR (will be +ive within few days, when serology may still be negative; also useful in immunocomp); blood
for serology (IgM = infection, levels peak at 7-10/7; IgG = immunity; may be negative if <4/7 from onset fever, need to
do rpt after 1/52, remains +ive for 3/12, sens 100%, spec 98%); double bag specs and don’t send through lamsen
Trt: Supportive; need infection control measures; notifiable disease; no school / child care for 5/7; admit if: poor PO
intake, resp compromise, CNS complications
Prophylaxis:
Exposed if: enter same room within 2hrs of infected person leaving
Non-immune if: not had 2x MMR and born after 1969, from 6/12 to 1st vaccine, if >4yrs and not had 2nd vaccine,
pregnant, immunocomp, or prem <28/40
Offer MMR if <72hrs (not if pregnant); if immunocomp / pregnant / >72hrs, consider Ig
HSP
Epidemiology: 2:1000; more Asian / Indian; usually 4-6yrs (2-11yrs)
Cause: Allergic vasculitis, follows URTI, IgA mediated; assoc with infection, drugs, vaccines; may be post Grp A strep
Pathology: Small vessels (skin, GIT, kidneys, jts)
Sx:
Palpable purpura on buttocks and legs (extensor surface) – presenting Sx
in 50%; maybe also erythematous, urticarial, echymoses, petechaie
AP (+N+V+D; in 60-80%; diffuse and colicky; occurs after rash; 50%
have blood in stool; 5% get acute GI haemorrhage; 3% get
intussusception)
Migratory polyarthralgia (66-80%; presenting Sx in 25%; usually
resolves after 24-48hrs; in gravity dependent jts)
Renal failure (in 20-50%) – nephritic syndrome; ESRF in <1%
Generalized oedema (eg. Feet; often painful)
Ix: Haematuria and proteinuria in 90%; urine, FBC (plts normal), U+E
Complications: Nephritic / nephrotic syndrome, ARF (<1%), HTN; if
proteinuria = more severe and needs FU; Intussusception (5%); bowel perf
Trt: Usually resolves in 3-4/52; supportive; monitor BP and urine for 6/12; IVF if ill; NSAIDS; Consider prednisone
1mg/kg for 2/52 (if abdo, jt or scrotal disease; may prevent renal complications (2% get long term renal impairment);
helps jt pain, abdo pain, oedema)
Admit if: Abdo, renal complications; symptomatic relief
Notes from: Dunn, Starship Guidelines
Paeds Rashes
How to Describe a Rash
Palpable lesions
Papules <0.5cm
Nodules
>0.5cm
Vesicles <0.5cm, clear fluid
Pustules
Yellow fluid
PurpuraPurple; palpable / non-palpable
Non-palpable lesions
Macules
Alterations in circumscribed area of skin
Pigmentation
Assessment
History Fever, systemic symptoms, prev immunizations, human/animal
contacts, travel, bites/stings, drugs, food, environmental exposure
Initial location of rash, pattern and timeframe of development, initial
Morphology
Examination Vitals
Undress – scalp, ears, neck, MM, skinfolds, digits, web interspaces,
palms, soles
Morphology, location, distribution
ENTEROVIRUSES
Echovirus 9, Coxsackievirus A9
Transmission Fecal-oral, oral-oral, RS-oral
Sx
Non-specific febrile illnesses, RTI, GI Sx, meningitis; variety of rashes
Maculopapular rash beginning on face and neck, extending to trunk and feet; may be lesions on
buccal mucosa and soft palate (resemble Koplik spots); maybe petechiae, vesicles, urticaria
Duration
5/7
Enterovirus (hand, foot and mouth disease)
Sx
Fever, anorexia, malaise, sore mouth  1-2/7 later, oral lesions  then cutaneous lesions
Oral lesions: painful 4-8mm vesicles on erythematous base on buccal mucosa, tongue, soft
palate, gingiva  ulcerate
Cutaneous lesions: 3-7mm red papules  grey vesicles on palms and soles (may be dorsum
of feet and buttocks)  heal in 7-10/7
Trt
Hydration, analgesia, mouthwash
Coxsackievirus (herpangina)
Sx
Fever, mouth pain, oral ulcers
Similar ulcers to hand, foot and mouth; but no skin lesions
RUBELLA
Incubation
Sx
Trt
12-25/7
1-5/7 fever, malaise, headache, sore throat  irregular pink macules and papules on face,
spreading to neck, trunk and arms; coalesces then clears
Forchheimer spots: pinpoint petechiae on soft palate that coalesce
Suboccipital and posterior auricular lymphadenopathy
Supportive
ERYTHEMA INFECTIOSUM (FIFTH DISEASE, SLAPPED CHEEK)
Sx
Trt
Abrupt appearance of rash  fiery red rash on cheeks; diffuse erythema of closely grouped
tiny papules on erythematous base; edges slightly raised; circumoral pallor; sparing of
eyelids and chin; lasts 4-5/7
1-2/7 after face rash  nonpruritic macular/maculopapular erythema on trunk and upper
limbs  spreads; lasts 1/52; spares palms and soles; fades with central clearing
Assoc with fever, malaise, headache, sore throat, cough, coryza, N+V+D, myalgia
Supportive
HERPES
Transmission
Sx
Trt
HSV-2 genital, HSV-1 oral
Herpes labialis, gingivostomatitis – painful umbilicated vesicles  unroof and crust over
Eczema herpiticum – break out on area previously affected by eczema
Herpetic whitlow – distal fingers
Consider sexual abuse
Oral acyclovir; supportive
CHICKENPOX
Sx
Trt
Pruritic generalized vesicular exanthem with mild systemic symptoms; starts on trunk / scalp
as faint red macules  vesicular in 24hrs, on erythematous base  dry and crust;
widespread, palms and soles spared; may occur on MM
Supportive if uncomplicated; cleanse lesions to prevent 2Y infection; antivirals only if
immunocompromised
ROSEOLA INFANTUM (SIXTH DISEASE)
Sx
Trt
Abrupt onset fever lasting 3-5/7, cough, coryza, anorexia, abdo discomfort  fever settles
 appearance of rash over 1-2/7. Erythematous, blanching, macular/maculopapular
eruption, discrete rose / pale pink 2-5mm lesions; most on neck, trunk and buttocks;
can also involve face and arms. No MM involvement. Lasts 1-2/7  fades rapidly.
Supportive
IMPETIGO
Cause
Sx
Trt
Staph aureus, beta-haemolytic strep
Lesions on face, neck, and extremities; usually no systemic Sx
Nonbullous: small erythematous macules and papules  thin walled vesicles  pustules 
rupture  golden yellow crust  smooth red surface underneath; may become confluent;
local adenopathy
Bullous: local; toxin causes separation of skin and bullae; thin walled bullae 0.5-3cm, filled
with clear-yellow fluid, rupture easily
Staph scalded skin syndrome: systemic; malaise, fever, irritability, tender skin; extensive
areas of exfoliation; Nikolsky sign +ive
Nonbullous: topical; oral only if severe
SSSS: inpatient, IVABx; may require admission to burns unit
ERYSIPELAS
Cause
Sx
Trt
Group A beta-haemolytic strep
Fever, chills, malaise, vomiting
Local redness, heat, swelling; raised indurated border; well demarcated
Penicillin
SCABIES
Sx
Trt
Severe pruritis; generalized eruption of linear burrows, papules, pustules, vesicles; mostly
affect hand, feet, groin; excoriation from scratching
Permethrin
ERYTHEMA TOXICUM
Sx
Trt
Erythematous macules 2-3cm on face, trunk, extremities; central 1-3mm pustules
None
SEBORRHOEIC DERMATITIS
Sx
Trt
NAPPY RASH
Greasy yellow/red scales, mostly on scalp; not pruritic
Mineral oil
Contact dermatitis: erythematous macular/papular with well demarcated borders; trt with hygeine
Candidal dermatitis: erythematous papular / pustular lesions; scaling around margins; satellite lesions