Adenoiditis pathophysiology

Adenoiditis Microchapters
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: Mahshid Mir, M.D. [2]

Overview

Adenoids are involved in the production of mostly secretory IgA, which is transported to the surface where it provides local immune protection. Adenoids can be infected by either bacterial and viral pathogens leading to adenoiditis.

Pathophysiology

• Adenoids are on the posterior nasopharynx, posterior to the nasal cavity. They are a component of the Waldeyer's ring of lymphoid tissue, which is a ring of lymphoid tissue and includes adenoids and tonsils.

• Adenoids are developed from lymphocytes infiltration in subendothelium of nasopharynx during the 16th week of gestation.

• After the birth adenoids begin to enlarge.
• By the time children are aged 6 months, lactobacilli, anaerobic streptococci, actinomycosis, Fusobacterium species, and Nocardia species are present.
• Normal flora found in the mature adenoid tissue consists:
  • Alpha-hemolytic streptococci
  • Enterococci
  • Corynebacterium species
  • Coagulase-negative staphylococci
  • Neisseria species
  • Haemophilus species
  • Micrococcus species
  • Stomatococcus species
• It is normal to find symptomatic adenoids in children aged 18-24 months.
• They continue their grow until individuals are aged 5-7 years.

• Adenoids start to shrink by the age 6-7.
• By the time children reach 10-12, the adenoids are usually small enough for the child to become asymptomatic.

Pathogenesis

• Adenoids are involved in the production of mostly secretory IgA, which is transported to the surface providing local immune protection. Studies suggest that a reduction in IgA will happen postoperative of adenoidectomy.

• Adenoiditis can happen as a result of infection and harbor pathogenic bacterial activity, which may lead to the development of disease of the ears, nose, and sinuses. Adenoiditis can progress to chronic disease if remain untreated for a long term.

• Parental history of tonsillectomy and atopy hold significant predictive power in pediatric adenoiditis.
• The pathogenesis of adenoiditis is characterized by its inflammation. This process is primarily due to an elevated rate of trafficking of lymphocytes into adenoid from the blood, exceeding the rate of outflow from the adenoid.
• The persistence of tonsillitis beyond 3 months is known as chronic tonsillitis. In case of chronic bacterial tonsillitis the bacteria persist in the tonsils and lead to chronic inflammation. This persistent infection and inflammation leads to chronic tonsillitis. Manifestations appear whenever the patient has decline in immunity.
• The immune response between the antigen and lymphocyte that leads to cellular proliferation and enlargement of the adeoid especially in paracortex area which lead to excess enlargement of the adenoids.
• Bacterial adenoiditis is primarily caused by group A β-hemolytic streptococcus (GABHS) Streptococcus pyogenes infection.
  • S. pyogenes and taxonomically-similar bacteria infiltrate the adenoidal epithelium, successfully penetrating the protective mucosal films in the oral and nasal cavity.
    • Colonization begins when the bacteria adheres to the adenoid surface proteins through lipoteichoic acid (LTA), depositing fibronectin molecules that bind to the adenoidal epithelium.
• Adenoid paracortex may also be enlarged secondarily as a result of the activation and proliferation of antigen-specific T and B cells (clonal expansion).
• On gross pathology, characteristic findings of adenoiditis, include:

• Enlarged adenoids
• Soft greasy yellow areas within capsule

• On microscopic histopathological analysis, characteristic findings of adenoiditis
• Recurrent bacterial tonsillitis is caused primarily by Staphylococcus aureus.
  • S. aureus invades the adenoids through microbial surface components recognizing adhesive matrix molecules (MSCRAMMs)
  • Following invasion, S. aureus is internalized by non-phagocytic cells through fibronectin-binding protein and beta-integrins.
  • Invasion of non-eukaryotic cells results in the up-regulation of cytokines, resulting in adenoiditis

	Pathogen	Symptoms	Treatment
Viral Tonsillitis	Epstein-barr virus (EBV)	Asymptomatic In small children, the course of the disease is frequently asymptomatic. Majority of adults infected with mono also remain asymptomatic with serological evidence of past infection. Initial Prodrome Common symptoms include: low-grade fever without chills is seen in nearly all cases, Sore throat, white patches on the tonsils and back of the throat are often seen, Muscle weakness and sometime extreme fatigue, tender lymphadenopathy, particularly the posterior cervical lymph nodes are involved	treating symptoms and complications of the infection.
	Human adenovirus	Common cold syndrome, Pneumonia, Croup, Bronchitis	treating symptoms and complications of the infection.
	Enterovirus	Mild respiratory illness (common cold), Hand, foot and mouth disease, acute hemorrhagic conjunctivitis, Aseptic meningitis, myocarditis, severe neonatal sepsis-like disease, acute flaccid paralysis.[2]	treating symptoms and complications of the infection.
	Rhinovirus	Sore throat, runny nose, nasal congestion, sneezing and cough; sometimes accompanied by muscle aches, fatigue, malaise, headache, muscle weakness, or loss of appetite.	Interferon-alpha Pleconaril
	Respiratory syncytial virus	Bronchiolitis (inflammation of the small airways in the lung) and pneumonia in children under 1 year of age Recurrent wheezing and asthma	treating symptoms and complications of the infection. Ribavirin
	Mononucleosis	Common symptoms include: Low-grade fever without chills is seen in nearly all cases, Sore throat: white patches on the tonsils and back of the throat are often seen, Muscle weakness and sometime extreme fatigue, tender lymphadenopathy, particularly the posterior cervical lymph nodes are involved Other symptoms that have been described in patients with EBV infection include: unable to swallow due to enlarged tonsils, dry cough, Loss of appetite, Anorexia, Nausea without vomiting, Abdominal pain- a possible symptom of a potentially fatal rupture of the spleen[1] Diarrhea	treating symptoms and complications of the infection.
	Toxoplasmosis	Symptoms are often influenza-like: Cervical lymphadenopathy, sore throat, muscle aches and pains that last for a month or more, fever, malaise, night sweats	Pyrimethamine Sulfadiazine Leucovorin (Folinic acid)
	Herpes virus	watery blisters in the skin or mucous membranes (such as the mouth or lips) or on the genitals.[1]	Acyclovir Valacyclovir Famcyclovir
	Cytomegalovirus (CMV)	mononucleosis like presentation. Retinitispresents with blurred vision and floaters. Colitis presents with abdominal pain and bloody diarrhea. Pneumonitis	Ganciclovir Foscarnet  Cidofovir
Acute Bacterial Tonsillitis	Haemophilus influenzae	bacteremia, and acute bacterial meningitis. Occasionally, it causes cellulitis, osteomyelitis, epiglottitis, and joint infections (otitis media) and eye (conjunctivitis) sinusitis pneumonia
	Group A β-hemolytic streptococcus	strep throat, acute rheumatic fever, scarlet fever, acute glomerulonephritis and necrotizing fasciitis rheumatic fever
	Staphylococcus aureus	Atopic dermatitis, Toxic shock syndrome
	Moraxella catarrhalis	Otitis media and sinusitis, tracheobronchitis and pneumonia	beta lactamase inhibitor antibiotics
	Streptococcus pneumoniae	Pneumonia, sinusitis, otitis media, endocarditis	Flouroquinolones Macrolide Penicillin and Beta lactamase inhibitors
Recurrent Bacterial Tonsillitis	Usually due to normal flora pathogens: Staphylococcus aureus Group A β-hemolytic streptococcus	Nasal airway obstruction, Snoring, sleep apnea, oral breathing, sore or dry throat from breathing through the mouth, purulent rhinorrhea, nasal obstruction, fever, ear pain, Headache, Sore throat
Chronic Bacterial Tonsillitis
Non-infectious Tonsillitis	Allergies	Allergic sinusitis Redness and itching of the conjunctiva (allergic conjunctivitis) Sneezing, coughing, bronchoconstriction, wheezing and dyspnea, sometimes outright attacks of asthma, in severe cases the airway constricts due to swelling known as angioedema	Antihistamines Cosrticosteroids Decongestants
	Asthma	Cough with or without sputum (phlegm) production, pulling in of the skin between the ribs when breathing (intercostal retractions), Shortness of breath that gets worse with exercise or activity, Wheezing	fast-acting bronchodilators (LABA) Short-acting selective beta2-adrenoceptor agonists Anticholinergic medications
	GERD	Heartburn, esophagitis, strictures, difficulty swallowing (dysphagia), vomiting, effortless spitting up, coughing, and other respiratory problems	Lifestyle Modifications Proton pump inhibitors Antacids  Alginic acid (Gaviscon)