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CHAPTER 37

Lymphadenopathy in African Children

S. W. Moore
N. Tsifularo
Ralf-Bodo Troebs

Introduction
Lymphadenopathy is an extremely common clinical finding in children
in Africa as well as the rest of the world. It is common in children due to
their large lymphoid mass and rapid lymphocytic response to allergens
or infections. It is therefore most prevalent in the first decades of life;
the majority of children between the ages of 2 and 12 years will have
an enlarged lymph node at one stage or another.
In broad terms, lymphadenopathy represents an enlargement of
lymph nodes resulting from:
• Reactive state – acute lymphadenitis
• Hyperplasia – e.g., human immunodeficiency virus (HIV), autoim-
mune disease
• Granulomas – tuberculosis (TB), mycobacteria other than tubercu-
losis (MOTT), toxoplasmosis, syphilis
• Neoplastic – primary (lymphomas) or secondary (metastases)
Lymphadenopathy is important because it may be the first (and
sometimes only) indication of underlying disease. The major cause is
infection, which may be acute bacterial or viral or chronic due to a host
of causes, the majority of which give rise to granulomas. It is therefore Figure 37.1: Anatomy of lymph nodes.
understandable that the incidence of lymphadenopathy is reportedly
higher in sick children than in those attending well baby clinics.
The obvious therapeutic and prognostic implications of Demographics
lymphadenopathy necessitate an accurate and prompt diagnosis. Size, Well-documented geographical differences exist in the epidemiology of
location, consistency, and nonresponse to empiric antibiotic therapy are lymphadenopathy in childhood. In general, the pathology usually identi-
the major criteria for further investigation. More than half the cervical fies what is common in that particular environment, which has a special
lymph nodes examined in children in a developing country display very significance for Africa, where tuberculosis remains one of the main
significant and clinically important pathology, thereby justifying active causes of lymph node enlargement. For example, in one South African
1
management of all paediatric patients with persisting lymphadenopathy. series, the incidence of Mycobacterium tuberculosis was 28%, similar
One of the main concerns is the association between malignancy and to the 24.9% reported in children worldwide, but that incidence is higher
lymphadenopathy, which may be primary or secondary but particularly than in developed countries such as Australia and countries in Europe
includes the lymphoma group of conditions. Lymphadenopathy and North America, where M. tuberculosis is less common, and paral-
therefore needs to be actively investigated should it not respond lels an increase in infections caused by “atypical mycobacteria” (i.e.,
to simple initial treatment so as not to overlook these important MOTT). As a result, chronic granulomatous conditions result mainly
conditions. It is important to institute early treatment. from MOTT infections and cat scratch disease in those countries.
Anatomy Aetiology
Lymph nodes are discrete encapsulated aggregations of lymphoid tis- Chronic lymphadenopathy in children of developing countries has
sue that are seldom palpable in the normal child. These bean-like ovoid a high incidence of infective causes, including pathogenic bacteria,
structures are scattered along lymphatic vessels but increase in number mycobacteria, and fungi, as well as neoplastic, metabolic, and immuno-
where the vessels converge, such as in the neck, axilla, pelvis, medias- logical causes, and other causes of lymph node reaction.
tinum, and similar situations (Figure 37.1). Infective causes may be further classified into acute or chronic.
Lymph nodes are structurally divided into three zones (the cortex, Acute Suppurative Lymphadenitis
the paracortex, and the medulla). The architecture of these areas often Acute suppurative lymphadenitis is secondary to infections of the upper
is important. These sites appear to have separate functions: the cortex is respiratory tract; ear, nose, and throat (ENT); or scalp. Submandibular
the main site of B-cell activation; the paracortex is the T-cell dependent lymph nodes are common sites in the 3–6 months age group
region; and the medulla, with abundant sinuses lined by macrophages, Acute lymphadenitis can result from poor dental and mouth hygiene.
has a reticulo-endothelial function. Involvement of the floor of the mouth is common in developing countries.
The primary function of the lymph node is to entrap and mount a Acute lymphadenitis often leads to suppuration and abscess
response against foreign agents as part of the reticulo-endothelial system. formation (Figure 37.2), and may lead to Ludwig’s angina.