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Infectious Exanthems of Childhood

William C. Koch, M.D.William C. Koch, M.D.Associate Professor of PediatricsAssociate Professor of Pediatrics

Division of Infectious DiseasesDivision of Infectious Diseases

School of MedicineSchool of MedicineVirginia Commonwealth UniversityVirginia Commonwealth University

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Definitions

ExanthemExanthem: a generalized : a generalized cutaneouscutaneous eruption associated with eruption associated with a systemic diseasea systemic disease

EnanthemEnanthem: an eruption on a mucus : an eruption on a mucus membrane associated with a membrane associated with a systemic diseasesystemic disease

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Differential diagnosis of infectious rashes based on:Past history of infection, exposure, Past history of infection, exposure, immunizationimmunizationType of Type of prodromalprodromal periodperiodFeatures of the rashFeatures of the rashPresence of Presence of pathognomonicpathognomonic or or diagnostic signsdiagnostic signsLaboratory diagnostic testsLaboratory diagnostic tests

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Clinical Case #1

7 y/o with 2 day history of fever, 7 y/o with 2 day history of fever, sore throat and abdominal sore throat and abdominal discomfort, 1 day history of discomfort, 1 day history of generalized rashgeneralized rashPE: alert but illPE: alert but ill--appearing; febrile; appearing; febrile; erythematouserythematous, finely , finely papularpapular rash; rash; exudativeexudative pharyngitispharyngitis, tender , tender cervical nodescervical nodes

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Differential Diagnosis of Scarlet Fever

Viral Viral pharyngitispharyngitis and rash and rash “Staphylococcal scarlet fever”“Staphylococcal scarlet fever”ArcanobacteriumArcanobacterium haemolyticumhaemolyticuminfectioninfectionKawasaki DiseaseKawasaki DiseaseToxic Shock SyndromeToxic Shock SyndromeMeaslesMeasles

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Diagnostic Criteria for Kawasaki Disease

Fever lasting at least 5 daysFever lasting at least 5 daysPresence of 4 out of 5 conditions:Presence of 4 out of 5 conditions:

Bilateral Bilateral conjunctivalconjunctival injectioninjectionChanges in the mucosa of Changes in the mucosa of oropharynxoropharynxChanges in the peripheral extremitiesChanges in the peripheral extremitiesUnilateral cervical node enlargementUnilateral cervical node enlargement

Illness not explained by other known Illness not explained by other known diseasedisease

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Complications of Streptococcal Scarlet Fever

SuppurativeSuppurative: cervical adenitis, : cervical adenitis, peritonsillarperitonsillar abscess, etc.abscess, etc.

NonsuppurativeNonsuppurative: rheumatic fever : rheumatic fever and acute and acute glomerulonephritisglomerulonephritis

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Clinical Case # 210y/o with history of URI 410y/o with history of URI 4--5 days ago, 5 days ago, now with rash on face spreading to trunk. now with rash on face spreading to trunk. Mother worried about measles. Attends Mother worried about measles. Attends public school; no travel or exposure public school; no travel or exposure history.history.

PE: PE: afebrileafebrile, doesn’t appear ill except for , doesn’t appear ill except for prominent rash: flushed facial appearance prominent rash: flushed facial appearance with diffuse, with diffuse, erythematouserythematous M/P rash on M/P rash on trunk and proximal extremities; palms and trunk and proximal extremities; palms and soles spared; HEENT exam is normal.soles spared; HEENT exam is normal.

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Differential Diagnosis

MeaslesMeaslesRubellaRubellaErythemaErythema infectiosuminfectiosum (fifth disease)(fifth disease)Infectious mononucleosisInfectious mononucleosisDrug eruptionDrug eruptionOther viral infectionOther viral infection

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Complications of Measles

Otitis mediaOtitis mediaLaryngotracheitisLaryngotracheitis (croup)(croup)Obstructive laryngitisObstructive laryngitisBronchopneumoniaBronchopneumoniaEncephalitisEncephalitisSSPESSPE

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Clinical Case #3

3y/o with 23y/o with 2--3 day history of fever, 3 day history of fever, decreased activity and complaints of decreased activity and complaints of HA. Presents in July; lives in rural area HA. Presents in July; lives in rural area but no history of tick bite or other known but no history of tick bite or other known exposure.exposure.PE: febrile, illPE: febrile, ill--appearing child, but alert appearing child, but alert and cooperative. Neck is supple. Faint and cooperative. Neck is supple. Faint petechialpetechial rash on distal extremities, rash on distal extremities, including palms and soles; none on including palms and soles; none on trunk. Rest of exam normal.trunk. Rest of exam normal.

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Differential Diagnosis of Fever and Petechial Rash

Rocky Mountain Spotted FeverRocky Mountain Spotted FeverMeningococcemiaMeningococcemiaOther Other rickettsialrickettsial infection (infection (ehrlichiosisehrlichiosis, etc.), etc.)Other bacterial infection/sepsis (e.g. Other bacterial infection/sepsis (e.g. H. H. influenzaeinfluenzae, , E. coliE. coli, etc.), etc.)Viral infection, esp. Viral infection, esp. enterovirusesenterovirusesTraumaTraumaTyphoidTyphoid

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Rocky Mountain Spotted Fever (RMSF)

Etiologic Agent: Etiologic Agent: RickettsiaRickettsia rickettsiirickettsii

Distribution: southeastern and south Distribution: southeastern and south central states primarilycentral states primarily

Vectors: dog tick (Vectors: dog tick (DermacantorDermacantorvariabilisvariabilis); wood tick (); wood tick (D. D. andersoniandersoni); ); Lone Star tick (Lone Star tick (AmblyommaAmblyommaamericanusamericanus))

Peak seasons: spring and summerPeak seasons: spring and summer36

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Features of the rash of RMSFBegins as Begins as erythematouserythematousmaculesmacules/papules and becomes /papules and becomes petechialpetechialFirst appears on wrist and ankles, First appears on wrist and ankles, spreading to extremities and proximal spreading to extremities and proximal trunktrunkPalms and soles often involvedPalms and soles often involvedRash usually occurs by sixth day of Rash usually occurs by sixth day of illnessillness

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Treatment of RMSFChloramphenicalChloramphenical or tetracycline is or tetracycline is highly effective if given early highly effective if given early –– during during the first week of illnessthe first week of illness

If the disease proceeds into the second If the disease proceeds into the second week, even optimal therapy becomes week, even optimal therapy becomes progressively less effectiveprogressively less effective

Adequate supportive care is essential: Adequate supportive care is essential: fluid management, monitoring, blood fluid management, monitoring, blood products, etc.products, etc.

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Infectious Exanthems of Childhood

William C. Koch, M.D.William C. Koch, M.D.Associate Professor of PediatricsAssociate Professor of Pediatrics

Division of Infectious DiseasesDivision of Infectious Diseases

School of MedicineSchool of MedicineVirginia Commonwealth UniversityVirginia Commonwealth University

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