common in adolescents, and GAS and S aureus are the most common organisms The diagnosis is clinical, although in some cases ultrasound can be used to aid the diagnosis and CT may be useful to evaluate for deeper extension of the abscess Empiric antibiotics should target streptococci and staphylococci (e.g., clindamycin) Standard precautions should be used Ludwig Angina Ludwig angina is a rapidly progressive cellulitis of the floor of the mouth with spread to other tissue planes, resulting in thrombophlebitis, carotid rupture, and mediastinitis This can be a complication of dental abscesses, especially of the mandibular molars Children with Ludwig angina develop fever, halitosis, odynophagia, submandibular lymphadenopathy, and induration to the floor of the mouth The most feared complication is airway obstruction Anaerobes, including microaerophilic (non-pneumococcal, non-group A) streptococcal species, are most commonly isolated Diagnosis is clinical, but imaging by CT can help evaluate the extent of infection Antibiotics should not be held pending imaging or other diagnostic evaluation Surgical consultation and admission to a critical care unit are necessary with strong consideration for early endotracheal intubation, anticipating that these children may be difficult to intubate Broad-spectrum coverage for aerobes and anaerobes (e.g., clindamycin, piperacillin/tazobactam) should be considered for this fulminant infection Standard precautions should be used Pharyngitis GAS accounts for 15% to 36% of exudative pharyngitis cases in older children and adolescents; the majority of the remaining etiologies are viral The Centor criteria (absence of cough, tender anterior cervical adenopathy, fever, and tonsillar exudate or swelling) were developed to identify adults at higher risk for streptococcal pharyngitis in whom empiric treatment without testing could be considered Testing is recommended prior to treatment to avoid unnecessary antibiotic usage in children; testing is generally not recommended for children younger than years of age Throat swabs should be obtained from both tonsillar pillars and swabs that first touch the tongue should be discarded, as saliva can result in false-negative rapid streptococcal assay results Rapid streptococcal assays show variable sensitivity based on the experience of the person collecting the specimen Reported sensitivities range from 60% to 99%; as such, throat cultures should be sent for all children in whom rapid streptococcal assays are negative The treatment of choice is amoxicillin or penicillin There are good data behind the use of a single-daily dose of amoxicillin (50 mg/kg daily, maximum: g/day) for 10 days For children with difficulty swallowing or in whom nonadherence is a concern, a single intramuscular dose of penicillin should be considered (penicillin G benzathine [Bicillin] ≤27 kg: 600,000 units; >27 kg: 1.2 million units) Regimens for penicillin-allergic patients include cephalosporins and macrolides There are no data suggesting that the use of cephalosporins decreases the risk of relapse or leads to symptoms resolution faster than more narrow-spectrum antibiotics Amoxicillinclavulanate offers no advantages over amoxicillin or penicillin, as there have been no GAS isolates found to be resistant to beta-lactams Use of antibiotics other than amoxicillin in the non-allergic patient represents poor antimicrobial stewardship Up to 20% of U.S GAS isolates are resistant to macrolides and 20% to 25% to clindamycin Standard precautions should be used LOWER RESPIRATORY TRACT INFECTIOUS EMERGENCIES Lower respiratory tract infections are one of the most common causes of death in children younger than years of age in developing nations The morbidity of these infections in industrialized nations remains high The following section will review the diagnosis and management of pneumonia and other common lower respiratory tract infections Tuberculosis is covered separately later in this chapter in the section on infection in returned travelers, reflecting the epidemiology of this disease in industrialized nations Pneumonia CLINICAL PEARLS AND PITFALLS