Adenoids during childhood: the facts.

Adenoids are constantly exposed to viral and bacterial agents as well as to allergens. They play a major role in the upper airways immunity, being effector organs in both mucosal-type and systemic-type adaptive immunity. Because of both their immunological function and their specific location, adenoids are considered to be as reservoirs of viruses and bacteria. Reiterative infections may therefore contribute both to Eustachian tube dysfunction and to tissue hypertrophy. Nasal endoscopy is a key diagnostic tool to detect both adenoid hypertrophy and adenoiditis. Moreover, such a procedure may be very helpful in detecting bacterial biofilms that could justify the concomitant presence of recurrent episodes of otitis media, chronic and occult sinusitis in children. Even though the connection between allergies and adenoidal diseases is not completely clear, allergic diseases cause an inflammatory state that influences adenoidal tissue as well, configuring the picture of allergic adenoiditis, a condition in which adenoid tissue exhibit numerous IgE positive mast cells. Several studies are still needed to better understand the relationship between allergies and infections and the influence they play on adenoids during childhood.