Lymphadenopathy in children: key points of diagnosis

Lymphadenopathy – this is a condition of hyperplasia (enlargement) of lymph nodes. This term is a preliminary diagnosis that requires further clarification with the help of clinical and laboratory examination and observation in dynamics. The main causes of lymph node hyperplasia in children can be grouped into the following groups:

infectious, which in turn are viral, bacterial, fungal, parasitic in nature;
associated with a malignant disease (leukemia, lymphoma, metastases of a solid tumor);
within immunological disorders: hemophagocytic lymphohistiocytosis, Langerhans cell histiocytosis, Kawasaki syndrome, as well as in autoimmune diseases: autoimmune lymphoproliferative syndrome, systemic lupus erythematosus, juvenile idiopathic arthritis, sarcoidosis, hereditary immunological defects;
hereditary metabolic diseases – accumulation diseases (for example, Niemann-Pick disease, Gaucher disease);
associated with taking certain medications (phenytoin, hydralazine, procainamide, isoniazid, allopurinol, dapsone).

In the process of differential diagnosis, it is fundamentally important for the doctor to answer a number of questions. Are the lymph nodes really enlarged? Is it about localized or generalized hyperplasia of lymph nodes? Does the process progress over time? Are there data in favor of an infectious etiology? Is there a suspicion of a malignant process? For example, on the localization of lymph nodes – supraclavicular always give reason to suspect a malignant etiology.

The most frequent problem in pediatric practice is the need to distinguish between infectious and malignant lymph node hyperplasia. There is a certain step-by-step algorithm for this, since it is not possible in all cases clinically to distinguish the age norm of the post-infectious state of lymph nodes. So, the signs of typical physiological lymph nodes under the age of 10 are palpable in the cervical, submaxillary, inguinal regions, size is less than 1 cm (submaxillary less than 2 cm), soft-elastic consistency, mobile, painless.

In children, the infectious etiology of lymphadenopathy is found in most cases. At the same time, both a local infection and a systemic infectious process can lead to an increase in lymph nodes.

Signs indicating the infectious nature of the condition: 1) visible local entry gates of infection (teeth, tonsils, aphthae on the oral mucosa, scratching marks in allergic dermatitis, other skin lesions), 2) local pain/hyperemia (redness) , 3) there is an indication of a systemic childhood infection (for example, rubella, scarlet fever).

The primary assessment, as already mentioned, is to identify the localization of enlarged lymph nodes. It is important to determine if these are hyperplastic lymph nodes of one group or if the process is widespread. In children, the neck area is most often involved. At the same time, bilateral (two-sided) damage to the lymph nodes of the neck is characteristic mainly of viral etiology (adenovirus, cytomegalovirus, Epstein-Barr virus, herpes virus type 6, HIV), and a similar picture can occur with streptococcal tonsillitis. Acute one-sided damage to the lymph nodes in the neck region is mostly characteristic of the staphylococcal nature of the disease, while the entrance gate of the infection – tonsils.

The subacute (chronic) course of the disease occurs, for example, with cat scratch disease, atypical mycobacteria, tularemia (which is rarely mentioned by anyone, but there are facts of registration of this disease in Europe now).

Hemogram (general blood test) + ESR, determination of C-reactive protein, as well as ultrasound of lymph nodes are helpful for diagnosis. Both blood tests and ultrasound imaging have their own characteristics in the inflammatory process.

One of the stages of the differential diagnosis algorithm is the appointment of antibacterial therapy, which is reasonable and appropriate for hyperplasia of the cervical group of lymph nodes. With an infectious etiology, a certain effect occurs within 10-14 days. This situation is interpreted as lymphadenitis.

The average observation period, as a rule, lasts 2 weeks. This time is enough to determine whether regression takes place, whether the condition remains unchanged or the disease progresses.

If positive dynamics do not occur on their own or after antibacterial therapy, or initially it is difficult to explain lymph node hyperplasia with a clear infectious cause, the algorithm provides for the expansion of diagnostic measures. These include:

determining the level of LDH (lactate dehydrogenase), ferritin, uric acid in the blood, since the increase in these parameters can be indirect markers of the neoprocess;

in-depth search for infectious agents that sometimes cause a subacute/chronic state of hyperplasia of lymph nodes (with appropriate anamnesis and clinical picture!) – examination for Epstein-Barr virus, cytomegalovirus, herpes virus type 6, as well as bacteria that cause cat scratch disease, brucellosis;
testing for HIV – when lymphadenopathy persists for more than 1 month;
Mantoux reaction;
Ultrasound + dopplerography of the involved group of lymph nodes;
Ultrasound of the organs of the abdominal cavity with an indication of the characteristics of intra-abdominal lymph nodes,
X-ray of chest organs to determine the condition of intrathoracic lymph nodes.

Here is an approximate diagnostic scheme, which is subject to correction in each specific case.

Special attention is drawn to lymph nodes larger than 1.5 cm in diameter, dense on palpation, especially if they are accompanied by the so-called B-symptoms. It should be explained here that B-symptoms include: a) profuse night sweats, b) temperature rise above 38°C, c) weight loss of 10% or more within 6 months. Such symptoms can be registered with tuberculosis, AIDS, invasive intestinal diseases (for example, amebiasis), Hodgkin's lymphoma. As a rule, in such situations, there is no time for observation, and it is advisable to conduct an open biopsy of the lymph node for diagnostic purposes.

In addition, there are cases when lymph node hyperplasia is accompanied by changes in the blood test – anemia and thrombocytopenia. If autoimmune diseases and hereditary immune defects are excluded, a bone marrow puncture is required for diagnostic purposes.

In the review, far from all, but the most frequent causes of lymphadenopathy are given. It is also important to remember that the knowledge and clinical experience of the doctor is sometimes more important than the meticulous execution of schemes, and the diagnosis of each patient may have individual characteristics.

According to the materials of the German Society of Pediatric Oncology and Hematology:

Minisymposium on infectious diseases in children (University Clinic Bern, Switzerland, 2012)

Management der Lymphadenitis Minisymposium Infektiologie 25. Oktober 2012.