The Role of the Adenoids in a Child's Immune System

The adenoids works with the other tonsils to trap germs entering the body through the mouth and nose. As part of the lymphatic system, they helps drain body fluids and fight off infection. The adenoids continue to enlarge after birth but usually begin to shrink around age five. By the time children reach the teenage years, their bodies have developed other ways to fight infection and the adenoids all but disappear.

The adenoids are made of respiratory tissue. They are shaped like a pyramid and divided into four lobes. The top of the pyramid points to the back of the thin wall between the nostrils called the nasal septum, and the bottom sits in the area behind the nose and above the roof of the mouth called the nasopharynx.

Studies show that the adenoids and other tonsils aid in the development of special lymphocytes called B cells/. The adenoids have special cells on the surface called M cells that detect antigens and activate B cells, which are involved in developing future immunity. There is also some evidence that the adenoids produce T cells, another lymphocyte essential to immune responses.

Most adults do not have adenoid tissue, but there are some exceptions. Those who are immunocompromised can present with nasal obstruction due to swollen adenoids. Organ transplant recipients taking medications to suppress the immune system or patients with HIV are most likely to develop this symptom. Doctors believe that the body regenerates adenoid tissue in response to infections that it can no longer fight off easily.

While rare in adults, enlarged adenoids are common in children. Some children are born with large adenoids, but, in many cases, the tissue swells because it is trying to fight off an infection. Sometimes, the adenoids shrink back to normal size when the infection is gone, but they can also remain enlarged. This is usually not a problem unless the increase in size interferes with the airway.

The most common symptom of enlarged adenoids is difficulty breathing through the nose. This causes children to breathe through their mouths instead and leads to a runny nose, dry mouth, cracked lips, and bad breath. Children with enlarged adenoids may also experience frequent ear infections. Parents may notice loud breathing, snoring, or sleep apnea.

Diagnosis of enlarged adenoids starts with a physical exam and medical history. The pediatrician checks the child's ears, nose, and throat and assesses the severity of symptoms. Because the adenoids are so high in the throat, the doctor may need special tools, including mirrors, an endoscope, or even an x-ray.

In some cases, the doctor may determine that the best treatment is adenoid removal. This procedure is called an adenoidectomy. The operation requires general anesthesia. There are multiple approaches to removing the adenoid, including using a special tool to scoop out the tissue. Other methods include using either electricity or radio waves to heat and remove the tissue. The child can usually go home after they can sit up, cough, and swallow.

For children experiencing severe obstructive sleep apnea, the most common treatment is an adenotonsillectomy. In this procedure, the surgeon removes both the adenoid and the tonsils. This surgery is done more than 500,000 times a year in the United States; it is the American Academy of Pediatrics's recommended treatment for sleep apnea in children over age two.

In some cases, non-surgical interventions for an enlarged adenoid are successful. One study showed that intranasal corticosteroids can improve symptoms and decrease swelling and that, with regular use, 76 percent of patients who had been candidates for surgery no longer needed it. Antibiotics are generally not effective when prescribed for a swollen adenoid, however, as the cause is often a resistant bacteria strain or virus.