Cervical Lymphadenitis and Neck Infections

Epidemiology

Neck masses in children, unlike those in adults, seldom represent ominous disease. Most (95%) masses are acute, enlarged, or inflamed lymph nodes and are transient in nature. In one series, 44% of children younger than 5 years had palpable lymph nodes. Other masses are congenital cysts and sinuses, vascular malformations, salivary and thyroid anomalies, benign and malignant neoplasms, traumatic injuries, and nonlymphatic infections. Malignancy accounts for 10%–15% of children hospitalized for a persistent neck mass. Although malignancy is uncommon, prompt diagnosis is crucial. US trends show that the incidence of head and neck malignancies among children younger than 15 years increased at a greater rate than childhood cancer in general.

Cervical lymphadenopathy (enlargement) and lymphadenitis (inflammation) are very common. There are few, current primary studies of etiology, and these represent a minority of cases. Attempts to delineate the causes and causative agents of acute lymphadenitis have been based on analysis of specimens obtained through needle aspiration and surgical biopsy, serologic testing, or current molecular methods. Staphylococcus aureus or Streptococcus pyogenes is isolated from 40% to 80% of culture-positive cases after aspiration of acutely inflamed, unilaterally inflamed nodes. ^, Community-acquired methicillin-resistant S. aureus (CA-MRSA) has emerged in the last two decades. ^, Anaerobic organisms outnumber aerobic and facultative organisms in normal oropharyngeal flora by more than 10:1. Anaerobic bacteria are isolated from 2% to 38% of cultures with higher yields if careful attention was paid to specimen collection and culture. ^, Pretreatment with antibiotics also is a factor in pathogen retrieval, with no pathogen isolated in at least 25% of cases of acutely inflamed nodes. ^,

For persistent cervical masses, biopsy may be needed for diagnosis. One large study from 1963 examined the biopsy results of persistent cervical masses in 267 children. Congenital cyst or cystic hygroma was found in 60%, malignant tumors in 16%, benign tumors in 7%, nonspecific lymphoid hyperplasia in 10%, and tuberculous granuloma in 7%. The 46 malignant tumors were as follows: 20 lymphosarcoma or Hodgkin disease, 11 neurogenic tumors (neuroblastoma, neurofibroma, neurofibrosarcoma), 11 thyroid tumors, and 4 parotid tumors.

In a review of peripheral lymph node excisional biopsies performed in 239 children, a specific cause was found in only 41% of cases. Of all excised nodes, 76% were located in the neck. Reactive hyperplasia accounted for 52% of cases, granulomatous diseases for 32%, neoplasia for 13% (cases suggestive of lymphoma before biopsy were excluded), and chronic lymphadenitis for 3%. Of the 31 cases of malignancy, Hodgkin lymphoma and non-Hodgkin lymphoma (NHL) accounted for 24, neuroblastoma for 4, and rhabdomyosarcoma for 3 cases. In this series, generalized lymphadenopathy was associated most often with reactive hyperplasia. Close follow-up of patients with a diagnosis of nonspecific reactive hyperplasia is important because studies indicate that up to 25% of such patients ultimately develop life-threatening lymphoreticular disease. ^{, , ,}

The use of polymerase chain reaction (PCR) and other molecular testing of surgical specimens has improved diagnostics in persistent, culture- or serology-negative cases. In a 2009 study of 60 children treated surgically for suspected infectious persistent cervical lymphadenitis, an etiology was identified in 82%. Methods combining conventional stain and culture with PCR to amplify the eubacterial 16S ribosomal RNA followed by more specific pathogen amplification were used. Organisms identified were both tuberculous and nontuberculous Mycobacterium (NTM) spp. (62%), followed by Bartonella spp. (10%) and Legionella spp. (10%). Interestingly, this is the first case series describing Legionella as a cause of persistent cervical lymphadenitis; diagnosis was made by PCR testing. As additional modes of molecular diagnostics become more available, spectrum of causative agents of adenitis likely will increase.

Surgical biopsy results from children in developing countries show a slightly different spectrum of disease. A review of 1332 patients younger than 15 years over a 23-year span in South Africa showed 48% reactive nodes, 25% Mycobacterium tuberculosis, 11.6% neoplasm, and 11.5% chronic granuloma. Miscellaneous etiologies included syphilis, yaws, toxoplasmosis, sinus histiocytosis, and Kaposi sarcoma.

Age is useful in predicting etiology of infection ( Table 17.1 ). Group B Streptococcus and S. aureus are common causes of lymphadenitis in neonates and young infants and S. pyogenes, S. aureus, and NTM spp. are more common in children 1–4 years old. Acute cervical lymphadenitis may be more common in the young child because of an inability to localize the organism to the initial nasal or pharyngeal site of attachment. In children aged 5–15 years and adults, anaerobic infection, toxoplasmosis, cat-scratch disease, and tuberculosis are important considerations and dental origination becomes more prominent.

Lymphatic Flow and Fascial Spaces of the Head and Neck

A complex and efficient lymphatic system has evolved to defend against microbial invasion of the head, neck, nasopharynx, and oropharynx, as shown in Table 17.2 and Fig. 17.1 . There are three interrelated lines of defense. The ring of Waldeyer is composed of a circle of adenoidal, tonsillar, and lingual lymphoid tissue (see Chapter 16 ). A collar of superficial satellite lymph nodes runs along the lower margins of the jaw and encircles this ring. This outlying collar of nodes of the head consists of the occipital, postauricular, preauricular, parotid, and facial groups. Nodes of the neck are the salivary gland−associated submaxillary and submental nodes and the vertically oriented superficial and deep cervical chains.

Occipital nodes often are enlarged when generalized lymphadenopathy is present; regional enlargement is almost always infectious and is due to tinea capitis, pediculosis capitis, seborrheic dermatitis, or scalp cellulitis or abscess. Enlargement of preauricular nodes reflects local skin or conjunctival infection. Asymptomatically enlarged parotid glands raise the possibility of malignancy.

Deep Neck Infections

The fascial system of the neck is complex, but a general anatomic description is useful to understand the deep neck infections. The neck fascia is divided into two layers: the superficial layer and the deep layer. The deep fascia is further divided into the superficial, middle, and deep layers of the deep fascia ( Fig. 17.2 ). The deep neck spaces interconnect and include the lateral pharyngeal (parapharyngeal), retropharyngeal, prevertebral, “danger,” masticator, submandibular, carotid, pretracheal, peritonsillar, parotid, and temporal spaces.

The most clinically relevant deep neck spaces include the submandibular , peritonsillar , retropharyngeal , and lateral pharyngeal spaces . Infection in the submandibular space is known as Ludwig angina . Ludwig angina is a bilateral, brawny cellulitis that originates in the floor of the mouth. The peritonsillar space surrounds the palatine tonsil. Peritonsillar abscess is the most common deep neck infection, accounting for 50% of cases, and is more common in adolescents and young adults. Abscess usually is unilateral but can be bilateral. Cervical and submandibular lymphadenopathy also can occur through drainage of the superior deep cervical nodes. ^, Infection of the retropharyngeal space is most common in children aged 2–4 years because the several small lymph nodes and space atrophy by adolescence. Infection in this space in older children and adults usually is secondary to direct trauma rather than to lymphatic spread. Cervical adenitis is not a common manifestation because these nodes drain into the prevertebral space; however, mediastinitis and empyema can occur.

The lateral pharyngeal space is a central connection for all other neck spaces, and thus infections can follow infection at various sites; presentation with unilateral cervical adenitis is common. The lateral pharyngeal space is divided into anterior and posterior compartments. Suppurative jugular thrombophlebitis (Lemierre syndrome) is a well-described complication predominantly of Fusobacterium infection of the posterior compartment, most commonly spread from primary tonsillitis. Along with sepsis because of proximity to the carotid sheath, swelling around the SCM muscle or “bull neck,” neck pain and stiffness, and torticollis are common. ^, More detailed descriptions regarding neck space infections are found in Chapters 25 and 28 Chapter 25Chapter 28.

Oculoglandular Syndrome of Parinaud

The oculoglandular syndrome of Parinaud consists of unilateral, chronic granulomas or ulcers of the conjunctivae associated with preauricular and submaxillary lymphadenitis. Causes are listed in Box 17.1 . Bartonella henselae infection is most common. Primary conjunctival inoculation causes grey or yellow granulomatous nodules or areas of focal necrosis, often surrounded by significant conjunctival chemosis and palpebral inflammation. Recovery without sequelae (except for occasional mild conjunctival scarring) occurs within 2–3 months. Antimicrobial therapy usually is given but has not been proved to hasten resolution.

Infectious Causes of Lymphadenitis

For purposes of predicting etiology, most cases of infectious cervical lymphadenitis can be divided into the following three categories (with some overlap): (1) acute bilateral lymphadenitis; (2) acute unilateral lymphadenitis; and (3) subacute (chronic) lymphadenitis.