← Diagnosis and Management Guides
Pediatric Rash
Key considerations: Meningococcemia (petechiae/purpura + fever + toxic), Kawasaki disease, Stevens-Johnson Syndrome / TEN
Cannot miss
- Meningococcemia (petechiae/purpura + fever + toxic)
- Kawasaki disease
- Stevens-Johnson Syndrome / TEN
- Staphylococcal Scalded Skin Syndrome (SSSS)
- Henoch-Schonlein Purpura (IgA vasculitis)
- Rocky Mountain Spotted Fever
Likely diagnoses
- Viral exanthem
- Hand-foot-mouth disease
- Urticaria (hives)
- Contact dermatitis
- Eczema flare
- Scarlet fever (strep)
Red flags
- Petechiae or purpura (especially with fever)
- Mucosal involvement (mouth, eyes, genitals) — think SJS/TEN
- Toxic or ill-appearing child with rash
- Peeling or desquamating skin
- Rapidly spreading rash with systemic symptoms
- Fever ≥5 days (Kawasaki)
- Target lesions spreading centrally (erythema multiforme)
Workup
- history: Onset and progression of rash; Associated fever — duration and height; Pruritus (itch); Medication exposure in last 2-4 weeks (drug reaction); Sick contacts, daycare attendance; Immunization status; Tick exposure (RMSF, Lyme); History of similar rashes; exam: Distribution and morphology of rash: macular, papular, vesicular, petechial, purpuric; Blanching vs non-blanching (press glass on skin); Mucosal involvement: oral, conjunctival, genital; Desquamation or Nikolsky sign (blister with lateral pressure — SSSS, TEN); Lymphadenopathy; Joint involvement (HSP, Kawasaki); Palms and soles involvement (RMSF, syphilis, Kawasaki, hand-foot-mouth); labs: CBC with differential and platelet count if petechiae/purpura; Blood culture if febrile with petechiae; CRP, ESR if Kawasaki suspected; Urinalysis if HSP suspected (renal involvement); Strep rapid test if scarlet fever suspected; imaging: Echocardiogram if Kawasaki suspected (coronary artery aneurysms); None routinely needed for most rashes; bedside: Glass test: press clear glass on rash — non-blanching = petechiae/purpura = emergency workup
Management
- immediate: Febrile child with petechiae/purpura: empiric IV ceftriaxone for meningococcemia BEFORE cultures return; SJS/TEN: stop offending drug, call burn center or dermatology, supportive care; general: Most pediatric rashes are viral and self-limiting; Photo-documentation of rash for comparison; specific: diagnosis: Meningococcemia; steps: IV ceftriaxone 100mg/kg IMMEDIATELY; Fluid resuscitation; ICU admission; Prophylaxis for close contacts; diagnosis: Kawasaki disease; steps: Diagnose: fever ≥5 days + 4 of 5 criteria; IVIG 2g/kg single infusion; High-dose aspirin until afebrile, then low-dose aspirin 3-5mg/kg/day; Echocardiogram at diagnosis, 2 weeks, 6-8 weeks; diagnosis: HSP (IgA vasculitis); steps: Supportive care: hydration, NSAIDs for joint pain; Monitor urinalysis weekly x4 weeks (renal involvement in 30-50%); Steroids ONLY for severe GI symptoms or nephrotic-range proteinuria; Nephrology referral if renal involvement
Disposition
- admit: Meningococcemia or sepsis; SJS/TEN; Kawasaki disease; SSSS; HSP with significant GI or renal involvement; discharge: Viral exanthem with well appearance; Urticaria without anaphylaxis features; HSP with mild symptoms and normal urinalysis; Scarlet fever with oral antibiotics prescribed; consults: Dermatology for SJS/TEN or SSSS; Cardiology for Kawasaki; Nephrology for HSP with renal involvement; Infectious disease for RMSF or meningococcemia
Clinical pearls
- Non-blanching rash (petechiae/purpura) + fever = MENINGOCOCCEMIA until proven otherwise — give antibiotics immediately
- Kawasaki disease: incomplete Kawasaki can be diagnosed with fever ≥5 days + 2-3 criteria + elevated CRP/ESR + supportive labs
- SJS/TEN: mucosal involvement distinguishes from other drug reactions — check mouth, eyes, genitals
- HSP: palpable purpura on BUTTOCKS AND LOWER EXTREMITIES is classic — always check urinalysis for hematuria/proteinuria
Source and review
- AAP Red Book 2024, AHA Kawasaki Disease Guidelines, Pediatric Dermatology (Paller & Mancini). Last reviewed: 2024-11-01