The Adenoids are a grouping of lymphoid tissue located on the posterior wall of the nasopharynx behind the soft palate. The adenoids, along with the faucial tonsils, lingual tonsils, and tubal tonsils of Gerlach make up what is known as Waldeyer’s ring. Together, these tissues function as an essential part of the human immune system. Antigens, introduced through the oral and nasal cavities, come into contact with the immune cells of Waldeyer’s ring. These cells can then produce immunologic memory of the antigens and fight them by producing IgA antibodies; this is thought to result in a “priming” of the immune system in infancy[rx].
The adenoids are present at birth and enlarge throughout childhood, reaching peak size by age seven. In most individuals, they will regress in size during puberty and may be nearly absent by adulthood. For this reason, adenoiditis is commonly a problem of childhood and adolescence. Adenoiditis occurs when there is inflammation of the adenoid tissue resulting from infection, allergies, or irritation from stomach acid as a component of LPR. Adenoiditis rarely occurs on its own and is more often involved in a more extensive disease process such as adenotonsillitis, pharyngitis, rhinosinusitis, etc. Continual irritation may lead to adenoid hypertrophy which is responsible for many of the complications of adenoid disease. Adenoiditis can be classified as acute or chronic.
Anatomy of Adenoids
The adenoids receive their blood supply from the ascending pharyngeal artery, maxillary artery, and facial artery. Venous drainage occurs through the pharyngeal veins. Nervous innervation is through the vagus nerve and glossopharyngeal nerve. Adenoid size grading is on a scale of zero to four[rx]:
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0 absent
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1+ <25% obstruction of the nasopharynx
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2+ 25-50% obstruction
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3+ 50-75% obstruction
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4+ >75% obstruction
Causes of Adenoids
Many agents and pathogens can cause inflammation of the adenoid tissue. A viral upper respiratory tract infection (URI) often precedes acute adenoiditis. In this vulnerable state, bacterial pathogens can infect the tissues and proliferate.
The most common bacterial pathogens cultured from adenoid specimens are[rx]:
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Haemophilus influenza
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Streptococcus pneumoniae
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Streptococcus pyogenes
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Staphylococcus aureus
Chronic adenoiditis is more often a polymicrobial infection and may include anaerobic pathogens and frequently results from biofilm development.[rx]
Allergies are believed to play a role in adenoiditis and subsequent adenoid hypertrophy. Allergens inhaled through the nose come in contact with the adenoid tissue. The tissues will proliferate in order to create a response to allergens and produce IgA.[rx]
Chronic irritation from stomach acid in the setting of gastroesophageal reflux disease (GERD) may also play a role in adenoiditis and adenoid hypertrophy, particularly in infants and young children.[rx]
Pathophysiology
Acute adenoiditis often occurs after a viral upper respiratory tract infection (URI). Bacterial agents proliferate and infect the adenoids and surrounding tissue resulting in inflammation and increased production of exudates. Symptoms include rhinorrhea, post-nasal drip, nasal obstruction, snoring, fever, and halitosis. Chronic adenoiditis shows many of the same symptoms but on a persistent basis lasting 90 days and is often caused by polymicrobial infections and biofilm formation. Exudates are frequently absent in chronic adenoiditis.[rx]
Another cause of adenoiditis is environmental allergens or caustic irritation from stomach acid in the presence of GERD/LPR.[rx]
Any form of chronic inflammation may lead to the proliferation of lymphoid tissue and subsequent adenoid hypertrophy. This hypertrophy can lead to nasal airway obstruction and obstruction of the Eustachian tubes which in turn leads to other problems such as obstructive sleep apnea (OSA) and otitis media.[rx]
Diagnosis of Adenoids
History and Physical
Adenoid tissue typically regresses around puberty. Therefore, the typical patient with adenoiditis is a prepubescent child with a recent history of URI. The patient may also have a history of recurrent acute otitis media, chronic nasal obstruction with mouth-breathing, chronic otitis media, sleep-disordered breathing/obstructive sleep apnea, or GERD/LPR.
Physical findings include purulent rhinorrhea, post-nasal drip, nasal obstruction, snoring, fever, mouth breathing, and halitosis. Indirect mirror exam may allow the practitioner to observe enlarged adenoids with exudates, though this can be a very challenging exam to perform in children. A flexible nasal and laryngeal endoscopic exam can allow for better evaluation of the adenoids but can require advanced training to use as well as the cooperation of the child and parents.
Long-standing adenoiditis with subsequent adenoid hypertrophy in early childhood can lead to the development of what is known as adenoid facies, or long face syndrome. Enlarged adenoids block the nasopharynx and result in obligate mouth breathing, which can lead to craniofacial abnormalities including a high-arched palate and retrognathic mandible.[rx]
Evaluation
The diagnosis of acute adenoiditis is made clinically based on the findings of: Possible concurrent acute otitis mediaFeverPurulent rhinorrheaPost-nasal dripNasal obstruction Throat painHalitosis, Visual inspection of the adenoids may be attempted using a laryngeal mirror or nasal endoscope.
Laboratory Testing
Rapid strep testCulturesAllergy testing
If it presents in the context of pharyngitis, the clinician may want to perform a rapid strep test. The purpose of doing so is two-fold. First, this will give a definitive diagnosis of the patient’s condition and help guide antibiotic therapy. Second, the doctor’s office will have a record of positive and negative strep tests which will play an important role when deciding whether an adenoidectomy, plus or minus tonsillectomy, is indicated. It is important to remember that adenoiditis remains a clinical diagnosis, so if the strep test is negative the physician can presume it is due to a different causative organism.
In cases of persistent infection despite antibiotic therapy, the clinician may choose to perform throat cultures to help identify the causative agent and guide therapy as direct cultures of adenoids may be difficult in the office setting.
If the adenoiditis is believed to be the result of seasonal or environmental allergies, allergy skin testing may be useful in directing therapy.
Radiology Testing
- Lateral neck X-ray
- Computed tomography (CT) of the sinuses
- Sinus X-rays or sinus CTs may be obtained to look for a source of infection in the sinuses if this is suspected clinically. This is rarely required in routine cases. Lateral neck X-rays are an effective way to evaluate specifically for adenoid hypertrophy. In a patient with adenoid hypertrophy who snores a sleep study can be obtained to rule out obstructive sleep apnea.
Treatment of Adenoids
Adenoiditis is often seen clinically as a component of rhinosinusitis or pharyngitis. Due to this fact, practitioners often use clinical management guidelines for rhinosinusitis and pharyngitis when approaching the treatment of adenoiditis.
Medical Management
- Watch and wait – If the clinician believes the cause of adenoiditis is by the common cold or other common viral infection they should refrain from using antibiotics. Typically, uncomplicated upper respiratory viral infections will resolve within five to seven days.[rx]
- Antibiotic treatment – If symptoms continue or clinical presentation is suggestive of bacterial etiology, such as a high fever or purulent discharge from the nose or throat, the first-line management is antibiotics covering the most common pathogens. Amoxicillin is a commonly used first-line agent due to its good coverage and tolerability. Alternatively, cefdinir or cefuroxime may be used, particularly if the patient has not responded to amoxicillin. If the patient has a penicillin allergy, alternatives include clarithromycin or azithromycin. Effective antibiotic treatment should yield an improvement of symptoms in 48-72 hours. Treatment duration should be ten days, as treating for a shorter duration yields significant relapse rates and breeds antibiotic resistance. If the condition fails to improve after a course of amoxicillin or other first-line agents, amoxicillin-clavulanate should be prescribed to eliminate potential beta-lactamase producing organisms.[rx]
- Allergy treatment – If the adenoiditis is believed to be secondary to environmental allergies, the patient can be given a trial of nasal steroid sprays, oral steroids, oral antihistamines, or some combination thereof to see if this produces any relief in symptoms. If this is effective, the patient may benefit from formal allergy testing followed by immune-modulating therapy to provide definitive relief.
- Reflux treatment – If the adenoiditis is believed to be secondary to LPR/GERD, treatment of this condition using lifestyle and diet modification with or without the use of H2 blockers or proton-pump inhibitors may provide sufficient relief of symptoms.[rx]
Surgical Management
Adenoidectomy – In the absence of symptomatic improvement after treatment with amoxicillin-clavulanate or if the patient has multiple episodes of adenoiditis requiring antibiotic treatment, referral to an otolaryngologist is warranted for further evaluation and potential surgical intervention. Depending on the individual circumstances, surgical procedures may include adenoidectomy with or without tonsillectomy or myringotomy with tympanostomy tube placement, or endoscopic sinus surgery. If the patient meets the Paradise criteria for tonsillectomy, most otolaryngologists will remove the adenoids at the same time to remove another possible source of recurrent infections.[rx]
Complications
If adenoiditis is left untreated, the patient may develop a chronic infection of the adenoids which in some cases can lead to the development of a biofilm. The adenoids may then serve as a nidus of infection for other closely related structures and lead to rhinosinusitis, pharyngitis, tonsillitis, and otitis media.[rx][rx]
Adenoid Hypertrophy
Adenoid hypertrophy is responsible for some of the more common complications related to disease of the adenoids. As they enlarge the tissues can create a significant obstacle to the flow of air through the nasopharynx. This enlargement can cause mouth breathing, snoring, and OSA. OSA can be a life-threatening disease if left untreated. Removing the adenoids can increase the flow of air through the nasopharynx, decreasing obstructive episodes, and leading to better CPAP compliance or resolution of the condition altogether.
Enlarged adenoids may also obstruct the opening of the Eustachian tubes in the nasopharynx. Without proper function of the Eustachian tube, negative pressure can build in the middle ear. This negative pressure can lead to the formation of an effusion which can cause conductive hearing loss and speech problems, as well as serve as a nidus for bacterial infections.
Long-standing adenoiditis with subsequent adenoid hypertrophy can lead to the development of what is known as adenoid facies or long-face syndrome. Enlarged adenoids can block the nasopharynx and result in obligate mouth breathing, which can lead to craniofacial abnormalities including a high-arched palate and retrognathic mandible.[rx]
