Introduction
Lymph node swelling refers to the swelling of a single or multiple lymph nodes. If this occurs immediately after vaccination (beginning a few hours to a few days after vaccination), a correlation between vaccination and lymph node swelling is possible. Frequent locations for lymph node swelling are the neck, armpit and groin region. However, other lymph nodes in the body may also be affected. In the case of lymph node swelling after vaccination, it is often mainly the lymph nodes in the armpit of the vaccinated arm, in children in the groin of the vaccinated leg.
Causes of lymph node swelling after vaccination
The lymph nodes store many cells that play an important role in the body’s immune system. In a vaccination, pathogens are injected into the body in an attenuated form. This is intended to teach the immune system how to fight the pathogen.
Therefore, a vaccination serves to train the immune system. The vaccination can produce cells that specifically recognize the surface of the affected pathogen. These cells are stored in the lymph nodes, for example, which is why lymph node swelling can occur after vaccination.
If the body is confronted with the pathogen again after vaccination, it can fall back on its already formed cells and thus fight the pathogen before the disease breaks out. However, another reason for lymph node swelling after vaccination can also be infections during the vaccination. The puncture in the skin means that there is little risk of other pathogens penetrating despite prior disinfection. Typically, this results in a significant redness and swelling of the puncture site, the immune system must also fight the additionally invading pathogen and may be overloaded, which may also be caused by lymph node swelling.
Other accompanying symptoms
A slight swelling of the lymph nodes after vaccination can be accompanied by some other symptoms, which also indicate an activation of the immune system (desired with vaccination). These include local symptoms such as swelling of the injection site. In addition, slight overheating and pain at the affected area may occur.
It is not uncommon to experience a slight fever/increased temperature or tiredness and fatigue. These symptoms usually disappear after a few days. Children are often somewhat more affected by the accompanying symptoms of a vaccination, they may also develop a slightly higher fever and be tired, limp and cranky for a few days. Occasionally, however, the swelling of the lymph nodes can also be an indication of a vaccination complication. This can lead to an infection of the injection site, which manifests itself by a distinct reddening (often spreading within a few hours) and a marked increase in fever.
