Peripheral lymphadenopathy in childhood - recommendations for primary diagnostic evaluation.

Background: Enlargement of peripheral lymph nodes most commonly caused by a local inflammatory process is frequently seen in childhood. The aim of the present study was to analyze the most common causes of peripheral lymphade nopathy and to develop a simple algorithm for the primary diagnostic evalua tion of peripheral lymph node enlargement in this age group. Patients: Betw een April and September 1999 87 unselected children (median age: 5(1)/(2), years) with peripheral lymphadenopathy were referred to the Department of P ediatrics, University of Graz, for further investigation. Results: EBV infe ction was diagnosed in 20 (23.0%) children. 19 (21.8 %) patients had acute bacterial lymphadenitis. In 21 (24.1%) patients lymph node enlargement was classified as "post/parainfectious (viral)". Four patients each had toxopla smosis and cat scratch disease. In 11 (12.6%) patients neither physical nor laboratory examinations revealed pathologic results. Among the remaining 8 children sarcoidosis and Hodgkin disease was diagnosed in one patient each . Small, soft, mobile, nontender, cervical, axillary or inguinal lymph node s do not require further investigations. In case of enlarged, tender lymph nodes with overlying skin erythema and fever diagnostic evaluation should i nclude complete blood count, erythrocyte sedimentation rate and/or c-reacti ve protein level, supplemented by appropriate antibody testing (EBV, CMV, T oxoplasma gondii, Bartonella henselae). Firm, enlarged, painless lymph node s which are matted together and fixed to the skin or underlying tissues nec essitate a more detailed diagnostic evaluation in order to exclude malignan t or granulomatous diseases. Conclusions: Our study demonstrated that prima ry diagnostic evaluation of childhood peripheral lymphadenopathy is mainly based on clinical grounds. In most cases a small number of additionally per formed laboratory tests allow to correctly identify the cause of the periph eral lymph node enlargement.