Approach to peripheral lymphadenopathy (pediatrics): Clinical sciences

Peripheral lymphadenopathy refers to subcutaneous lymph nodes that have an abnormal size or consistency. Lymph node size varies by age and normally increases from infancy to childhood, with a subsequent decrease in size during late childhood and adolescence. In general, enlarged lymph nodes are 1 centimeter or larger, but any degree of lymph node enlargement in atypical areas, such as the supraclavicular region, is considered abnormal. The most important underlying causes of peripheral lymphadenopathy include malignancy, autoimmune conditions, and infections.

Now, if your patient presents with peripheral lymphadenopathy, obtain a focused history and physical examination. Patients or their caregivers typically describe a lump or mass, occasionally with symptoms like fever, fatigue, or poor appetite. Additionally, the physical exam findings will reveal one or more enlarged subcutaneous lymph nodes that could be tender to palpation. These findings confirm the presence of peripheral lymphadenopathy.

Now, the next step is to assess for malignancy. Physical exam findings include nontender nodes that are firm and immobile and fixed to the surrounding tissue as well as nodes that are matted, meaning that nodes are joined together so they feel connected when palpated. Palpable supraclavicular nodes are also concerning for malignancy, as well as persistently enlarged nodes. If your patient has any of these findings, consider the possibility of malignancy.

Next, assess for signs and symptoms of leukemia or lymphoma. Let’s start with leukemia. These patients often report abnormal bleeding or bone pain, while their physical exam typically reveals pallor, bruising, or petechiae. With these findings, consider leukemia and obtain a CBC with a peripheral smear and consider performing a bone marrow biopsy. If the CBC reveals leukocytosis and anemia; and if immature blasts are seen on the peripheral blood smear or bone marrow biopsy, diagnose leukemia.

Now, let’s move on to lymphoma. These patients typically report night sweats, and possibly dyspnea or cough. Their physical exam usually reveals hepatosplenomegaly. With these findings, consider the possibility of lymphoma, and obtain a lymph node biopsy and possibly a chest X-ray. A biopsy revealing malignant cells and chest X-ray findings indicating a mediastinal mass confirm the diagnosis of lymphoma.

Now let’s discuss patients with no signs or symptoms suggestive of malignancy. In this case, your next step is to assess for signs and symptoms suggesting an autoimmune condition. The history may reveal symptoms like joint pain or fever, and a physical exam may detect a rash, along with non-tender, mobile lymph nodes. With these findings, consider the possibility of an autoimmune condition.

First, let’s discuss Kawasaki disease! These patients typically have a fever for at least 5 days. Physical exam reveals bilateral nonexudative conjunctivitis, cracked lips, a strawberry tongue, and a polymorphic rash, in combination with erythema or edema of the hands or feet and a single enlarged cervical lymph node. With these findings, diagnose Kawasaki disease.

Next up is systemic lupus erythematosus, or SLE! If your patient reports skin photosensitivity, and the physical exam reveals a malar rash, oral ulcers, and joint swelling, consider SLE. In this case, order labs, including a CBC, urinalysis, antinuclear antibody test, or ANA, anti-double stranded DNA, or anti-ds DNA, and anti-Smith antibody. The CBC may demonstrate leukopenia, anemia, or thrombocytopenia; and urinalysis may reveal blood. If the ANA, anti-ds DNA, or anti-Smith antibody are positive; diagnose SLE.

Finally, let’s discuss systemic juvenile idiopathic arthritis, or systemic JIA for short. Affected patients are less than 16 years old that report pain and stiffness in one or more joints for six weeks or more, along with fever which is often accompanied by a salmon-pink macular rash in patients with light skin. The exam shows joint swelling and hepatomegaly. With these findings, consider systemic JIA and obtain labs, including CBC, ANA, and rheumatoid factor, or RF. If the CBC reveals leukocytosis and thrombocytosis in combination with negative ANA and RF, diagnose systemic JIA.

On the other hand, if your patient has no signs or symptoms of an autoimmune condition, your next step is to assess for signs and symptoms of infection. If symptoms have been present for less than 4 weeks and the exam reveals tender, mobile lymph nodes, consider the possibility of an infection, and assess the distribution of the lymphadenopathy.

If only a single lymph node is enlarged, consider a primary lymph node infection. Let’s start with bacterial lymphadenitis. In these patients, history reveals an abrupt onset of fever, occasionally with other symptoms like sore throat. The physical exam reveals erythema of the skin overlying an enlarged, warm, and tender lymph node, typically in the cervical chain. Some patients may also have pharyngeal erythema with enlarged tonsils. In this case, you can make a clinical diagnosis of bacterial lymphadenitis.

Now, here’s a clinical pearl to keep in mind! In neonates, acute bacterial lymphadenitis is most commonly caused by group B streptococcus, while in older children, group A Streptococcus and Staphylococcus aureus are common causes.

And here’s another clinical pearl! Nontuberculous mycobacterial lymphadenitis is a subacute infection that develops over several weeks or months and typically presents without fever or systemic symptoms. These patients have firm, non-tender adenopathy with violaceous skin overlying the affected node.

Now let’s move on to cat-scratch disease! If your patient reports exposure to a cat, and you detect erythema overlying a tender cervical or axillary lymph node, consider the possibility of cat-scratch disease. Next, perform serologic testing for Bartonella henselae with enzyme immunoassay. Positive serologic testing confirms the diagnosis of cat-scratch disease.