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Concept
Adenoid hypertrophy
Résumé
Adenoid hypertrophy (enlarged adenoids) is the unusual growth (hypertrophy) of the adenoid (pharyngeal tonsil) first described in 1868 by the Danish physician Wilhelm Meyer (1824–1895) in Copenhagen. He described a long term adenoid hypertrophy that will cause an obstruction of the nasal airways. These will lead to a dentofacial growth anomaly that was defined as "adenoid facies" (see long face syndrome).
There is very little lymphoid tissue in the nasopharynx of young babies; humans are born without substantial adenoids. The mat of lymphoid tissue called adenoids starts to get sizable during the first year of life. Just how big the adenoids become is quite variable between individual children.
Enlarged adenoids can become nearly the size of a ping pong ball and completely block airflow through the nasal passages. Even if enlarged adenoids are not substantial enough to physically block the back of the nose, they can obstruct airflow enough so that nasal breathing requires an uncomfortable amount of work, and inhalation occurs instead through mouth breathing. Adenoids can also obstruct the nasal airway enough to affect the voice without actually stopping nasal airflow altogether.
Nasal blockage is determined by at least two factors: 1) the size of the adenoids, and 2) the size of the nasal pharynx passageway.
The adenoid usually reaches its greatest size by about age 5 years or so, and then fades away ("atrophies") by late childhood - generally by the age of 7 years. The lymphoid tissue remains under the mucosa of the nasopharynx, and could be seen under a microscope if the area was biopsied, but the mass is so reduced in size that the roof of the nasopharynx becomes flat rather than mounded. Just as the size of the adenoids is variable between individuals, so is the age at which adenoids atrophy.
The symptoms caused by enlarged adenoids are mostly due to where this lymphoid tissue is located. The adenoids are in the midline of the nasopharynx, and the Eustachian tubes open from either ear to the right and left of them.
Source officielle
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