• Evaluate ABCs. Note general appearance, color, and mental status. Check for increased work of breathing; assess perfusion by checking capillary refill and pulses.
Vital signs: Tachycardia is a sign of compensated shock. Hypotension signifies decompensated shock
Pay close attention to oral mucosa. Bright red lips or strawberry tongue suggest Kawasaki disease. Ulcerative lesions of erythema multiforme (EM) or vesicles of enterovirus are diagnostic clues.
• Note altered mental status (confusion, agitation, or lethargy) and meningeal signs such as a positive Kernig or Brudzinski sign.
• Perform a complete joint examination. There may be a painless joint effusion in Lyme disease. Joint swelling, warmth, morning stiffness or pain may occur in rheumatologic processes such as juvenile idiopathic arthritis (JIA).
• The rashes of RMSF, ehrlichiosis, erythema multiforme, Stevens-Johnson syndrome, enterovirus, group A streptococcus, Kawasaki disease, and drug reactions may involve palms and soles.
Tests for Consideration
Complete blood count (CBC) with differential:
Leukopenia suggests overwhelming infection or viral suppression;
Leukocytosis and thrombocytosis are nonspecific for infection;
Thrombocytopenia in sepsis, RMSF, and ehrlichiosis;
Thrombocytosis in Kawasaki disease $116
Blood culture: If ill-appearing $152
• Complete metabolic panel: Hyponatremia occurs in RMSF and other tick-borne illnesses $237
• Liver transaminase levels: Elevated levels may signal organ inflammation or inadequate perfusion $132
• RMSF acute and convalescent titers $349
• Group A streptococcus antigen $148
• Rapid respiratory panel to check for adenovirus $325
• Lumbar puncture if clinically indicated:
• Enterovirus polymerase chain reaction (PCR) $300
• Lyme PCR $180
• Gram stain $180
• Culture $152
• Cell count $150
• Glucose and protein $75
• Urinalysis: To check for hematuria, proteinuria, or casts $95
• Urine culture $148
• Prothrombin time (PT) and partial thromboplastin time (PTT): If petechiae and/or purpura $105
Erythrocyte sedimentation rate (ESR): To monitor inflammatory response in HSP or Kawasaki disease $85
• Renal biopsy: For persistent HSP $1325
IMAGING CONSIDERATIONS
Kawasaki Disease
KD represents a febrile multisystem vasculitis with preferential involvement of medium-size arteries. Inflammation may involve all three layers of the vessel wall, with possible aneurysm formation. An infectious etiology has been postulated.
TPThe child is extremely irritable. In classic Kawasaki disease, there is fever for at least 5 days, with at least four of the following:
  • Bilateral nonexudative conjunctivitis
  • Erythema of oral and pharyngeal mucosa with strawberry tongue, dry cracked lips
  • Edema and erythema of hands
  • Rash
  • Cervical lymphadenopathy, unilateral >1.5 cm
In incomplete or atypical Kawasaki disease, patients present with 5 days of fever and fewer than four additional findings. This is more common in infants under 1 year, in whom diagnosis is more difficult but who have higher rates of coronary artery aneurysms. Also possible are myocarditis, hydrops of the gallbladder, mild hepatitis, aseptic meningitis, arthritis, and urethritis.
DxDiagnosis is clinical, and there are three phases:
  • Acute febrile phase lasts 1 to 2 weeks: fever and other signs and symptoms, including perineal desquamation
  • Subacute phase lasts 2 to 4 weeks. Fever and other symptoms have resolved, but irritability, anorexia, and conjunctivitis persist; new periungual desquamation of fingers and toes, marked thrombocytosis of up to 1,000,000/mm 3 , and coronary artery aneurysm formation.
  • Convalescent phase up to 8 weeks from onset; all symptoms resolve. ESR and C-reactive protein (CRP) are normal.
Echocardiogram is done at diagnosis and if normal, is repeated at 2 to 3 weeks and again 6 to 8 weeks after onset.
TxIntravenous immunoglobulin (IVIG) 2 g/kg within 10 days of onset decreases symptoms and markedly reduces coronary artery aneurysm formation. Children with KD are also treated with high-dose aspirin (antiinflammatory dosing) for 14 days, or until afebrile for 3 to 4 days, followed by low-dose aspirin (antithrombotic dosing) until 6 to 8 weeks from onset. Persistent or recurrent disease may require a second course of IVIG. Factors associated with poor outcome include male gender, age <1 year, prolonged fever, or fever recurrence after an afebrile period. 1 See Nelson Essentials 88.