airway compromise, and IV antibiotic treatment using clindamycin, ampicillin/sulbactam, or cefazolin Most children will need drainage, but IV antibiotics and observation may be sufficient for those determined to have retropharyngeal cellulitis, phlegmon, or small collections The Children’s Hospital of Philadelphia Clinical Pathway ED Clinical Pathway for the Evaluation/Treatment of the Child With a Suspected Deep Neck Space Infection URL : https://www.chop.edu/clinical-pathway/neck-infection-clinicalpathway Authors : R Abaya, MD; M Joffe, MD; L Vella, MD; M Dunn, MD; S MacFarland, MD; M Rizzi, MD; K Shekdar, MD; R Bellah, MD; J Lavelle, MD Posted : February 2017, reviewed October 2019 Lemierre syndrome and Ludwig angina represent two additional deep space infections that can present with neck mass Lemierre syndrome is an infection of the parapharyngeal space with progression to septic thrombophlebitis of the internal jugular vein, and subsequent septic embolization to the lungs and/or central nervous system When adolescents and adults are affected, initial symptoms include sore throat, fever, and fullness to one side of the neck associated with neck pain, trismus, dysphagia, and dyspnea Once clinically apparent, patients become toxic The predominant pathogen is a gram-negative bacillus Fusobacterium necrophorum, though S aureus can also cause a similar presentation Anticoagulation is still controversial Ludwig angina is an infection of the floor of the mouth following a dental procedure or trauma Patients may present in a toxic state, with submental swelling, and elevation of oral soft tissues which can result in acute airway compromise Causative agents are generally anaerobic oral flora Treatment for either illness consists of either penicillin in combination with a β-lactamase inhibitor or a β-lactamase–resistant antibiotic in combination with a drug that is highly effective against anaerobes (e.g., clindamycin or metronidazole) for at least weeks Incision and drainage may be required when abscess is present Neoplasms While it is estimated that 80% to 90% of neck masses in children are benign, differentiating between a benign and malignant lesion can be difficult, and