Impact of Adenoidectomy on Immune Function in Young Children

27 July, 2025 Doctor Pediatrician 1 category

This article can be shared freely under the Attribution 4.0 International license.

Recent research on the lasting effects of removing tonsils and adenoids during childhood indicates a higher likelihood of respiratory, infectious, and allergic diseases.

For many individuals, the removal of tonsils is a common experience during childhood. This procedure, known as a tonsillectomy, is one of the most frequently performed pediatric surgeries globally, with over 530,000 operations conducted annually on children under 15 in the US alone.

Typically done to address recurrent tonsillitis and middle ear infections, a tonsillectomy often coincides with adenoid removal, known as an adenoidectomy. Adenoid surgery is also carried out to enhance breathing when airways are blocked.

Previously, it was believed that adenoids and tonsils became unnecessary by adulthood. However, we now understand that adenoids and tonsils are strategically positioned in the nose and throat, respectively, forming Waldeyer’s ring. They serve as a primary defense line, aiding in the recognition of airborne pathogens like bacteria and viruses, initiating the immune response to eliminate them from the body.

According to researchers, these new findings are crucial to consider along with the already known short-term risks of surgery. The study, published in the JAMA Otolaryngology Head and Neck Surgery, presents additional evidence to support potential alternatives to surgery whenever feasible.

Triple risk of upper respiratory trouble

Analyzed from a comprehensive dataset from Denmark, containing health records of 1,189,061 children born between 1979 and 1999, the study spanned at least the first decade and up to 30 years of their lives.

Out of nearly 1.2 million children, 17,460 underwent adenoidectomies, 11,830 tonsillectomies, and 31,377 had adenotonsillectomies, where both tonsils and adenoids were removed.

After these operations, the children’s health was monitored for diagnoses of 28 respiratory, infectious, and allergic diseases, comparing those who had undergone surgery with those who hadn’t, ensuring all children were generally in good health.

“We evaluated the risk of developing diseases later in life based on whether adenoids, tonsils, or both were removed before the age of 9,” explained Byars, who spearheaded the study alongside Stephen Stearns of Yale University and Jacobus Boomsma from the University of Copenhagen.

“This age range was chosen as it aligns with when these surgeries are commonly performed and when tonsils and adenoids are most active in the body’s immune responses and development.”

Following adenoid removal, the relative risk of inflammation of the middle ear was found to increase four or five times for those who had the surgery.

Tonsillectomy was linked to an almost tripled relative risk for diseases of the upper respiratory tract—the risk for individuals who underwent the procedure in comparison to those who didn’t—including asthma, influenza, pneumonia, and chronic obstructive pulmonary disorder (COPD). The absolute risk also significantly rose to 18.61 percent.

“Hence, the impact of tonsillectomy on respiratory diseases later in life could be considerable for these individuals,” Byars added.

The researchers discovered that adenoidectomy was associated with more than doubled relative risk of COPD and nearly doubled relative risk of upper respiratory diseases and conjunctivitis. The absolute risk for upper respiratory diseases also nearly doubled, but only slightly increased for COPD, as it is less common in the community generally.

The team further analyzed the data to determine the number of operations needed for an additional disease occurrence than usual, known as the “number needed to treat” or NNT.

“In the case of tonsillectomy, we found that only five operations were required to result in one extra upper respiratory disease manifestation in an individual,” shared Byars.

Greater risk of ear infection

The study also examined the conditions targeted by these surgeries directly, with varied outcomes. Adenoidectomy was tied to a significantly reduced risk of sleep disorders, while all surgeries were linked to decreased risks of tonsillitis and chronic tonsillitis, as these organs had been removed.

“…our findings endorse delaying tonsil and adenoid removal whenever feasible, which could support the regular development of the immune system in childhood…”

Nonetheless, there was no observed alteration in abnormal breathing up to the age of 30 following any surgery, nor any change in sinusitis after tonsillectomy or adenoidectomy.

After adenotonsillectomy, the relative risk of otitis media (middle ear inflammation) increased four to five times for those who underwent the surgery, and sinusitis also displayed a notable rise.

The research suggests that the shorter-term advantages of these surgeries may not persist till the age of 30, except for the reduced risk of tonsillitis (across all surgeries) and sleep disorders (in adenoidectomy cases). Instead, the long-term risks of abnormal breathing, sinusitis, and otitis media post-surgery were either significantly higher or remained unchanged.

Are tonsils the new appendix?

The researchers underscore the necessity of tonsil and adenoid removal in severe cases.

HPV may hide out in tonsil ‘crypts’

“However, our results support delaying tonsil and adenoid removal if possible, which could aid normal immune system development in childhood and reduce the possible later-life disease risks we observed in our study,” stated Byars.

“In 1870, Charles Darwin famously remarked on the appendix as an evolutionarily useless organ, predicting its minimal contribution to digestion. We now understand its crucial role in the immune system, safeguarding against gut infections by fostering beneficial bacteria growth.”

As we gain more insights into the function of immune tissues and the enduring effects of their removal—particularly during critical developmental stages—it will guide both parents and healthcare professionals in determining appropriate treatment strategies.