# A nurse is assessing a 16-year-old adolescent who presents with fever, sore throat, and fatigue for the past week. Which assessment finding would be most characteristic of infectious mononucleosis?

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## 문제

A nurse is assessing a 16-year-old adolescent who presents with fever, sore throat, and fatigue for the past week. Which assessment finding would be most characteristic of infectious mononucleosis?

## 보기

1. Enlarged lymph nodes in the neck and axilla with splenomegaly **✔ 정답**
2. Petechial rash on the trunk and extremities with splenomegaly
3. Productive cough with thick yellow sputum and splenomegaly
4. Joint pain and swelling in multiple joints with splenomegaly

**정답: 1**

## 해설

Infectious mononucleosis typically presents with enlarged lymph nodes (especially cervical and axillary) and splenomegaly, which are key distinguishing features. Other options like petechial rash, productive cough, or joint pain are not characteristic.

## 심화 해설

Understanding the Classic Triad

Infectious mononucleosis (IM), most commonly caused by the Epstein-Barr virus (EBV), is a condition frequently tested on the NCLEX-RN. The classic clinical presentation in adolescents and young adults centers on a triad of symptoms. The provided case report confirms that IM "typically presents with fever, pharyngitis, and lymphadenopathy" [1]. While fatigue and sore throat are prominent, the most characteristic assessment finding that distinguishes IM from other common infections is the pattern of lymph node involvement and associated organomegaly.

Why Option 1 is the Most Characteristic

Option 1 describes enlarged lymph nodes in the neck and axilla with splenomegaly. This aligns perfectly with the pathophysiology of EBV infection. The virus infects B lymphocytes and epithelial cells, triggering a robust T-cell response. This immune battle leads to hyperplasia of lymphoid tissues. The posterior cervical lymph nodes are classically affected, but axillary and inguinal chains can also be involved. Splenomegaly is a hallmark finding, occurring in approximately 50% of cases, because the spleen is a major lymphatic organ actively filtering the infected lymphocytes. The case report on splenic infarction explicitly identifies IM as a "common illness in adolescents and young adults" and highlights splenomegaly as a key feature that can lead to complications [2]. On physical examination, you would palpate firm, tender, and symmetrically enlarged nodes, along with a potentially palpable spleen tip below the left costal margin.

Differentiating from Other Presentations

To select the correct answer, it is crucial to understand why the other options are not the *most* characteristic for uncomplicated IM.

- **Option 2 (Petechial rash):** While a petechial rash on the soft palate (Forchheimer spots) can occur, a generalized petechial rash on the trunk and extremities is not a primary characteristic. This presentation is more concerning for other conditions like meningococcemia or a severe drug reaction. Notably, the research on age-dependent patterns in children emphasizes the clinical heterogeneity of EBV but does not list a diffuse petechial rash as a defining feature .

- **Option 3 (Productive cough):** A productive cough with thick yellow sputum is indicative of a bacterial respiratory infection, such as bronchitis or pneumonia. IM is a viral illness that may cause pharyngitis with tonsillar exudates, but it does not typically involve a productive lower respiratory tract cough. This finding would steer a clinician away from a primary diagnosis of IM.

- **Option 4 (Joint pain and swelling):** Polyarticular joint pain and swelling are characteristic of autoimmune or rheumatologic conditions, such as juvenile idiopathic arthritis or systemic lupus erythematosus, not IM. While arthralgias can occur in some viral syndromes, they are not a defining or most characteristic feature of EBV infection. The comparative study of clinical features in children and adults with IM focuses on fever duration and hepatic injury, not on joint manifestations .

Clinical Application and Nursing Assessment

When assessing an adolescent with suspected IM, your focused assessment should prioritize palpation of the lymph node chains, especially posterior cervical and axillary, and gentle palpation of the abdomen for splenomegaly. The study on splenic infarction as a complication underscores the critical importance of this assessment, as an enlarged spleen is fragile and at risk for rupture [2]. A finding of significant lymphadenopathy coupled with splenomegaly in a febrile, fatigued adolescent with a sore throat is a high-probability indicator of IM. This should prompt you to anticipate diagnostic tests, including a complete blood count (looking for lymphocytosis with atypical lymphocytes) and EBV-specific serology (positive viral capsid antigen IgM, negative EBNA IgG) as mentioned in the pediatric study . Your nursing care plan will then include monitoring for complications like airway obstruction from tonsillar hypertrophy, splenic rupture precautions (avoiding contact sports and abdominal palpation), and supportive care for the prolonged fatigue, which the adult study notes can lead to longer hospitalization .

References (research sources)

- [1]Infectious Mononucleosis: An Uncommon Presentation of a Common Disease-a Case Report.Case reportMoini M, Sheibani S, Ghazizadeh M. (2026) · DOI: 10.1002/ccr3.72222

- [2]Splenic Infarction as a Complication of Acute Epstein-Barr Virus Infection in an 18-Year-Old Woman.Research articleAngbuhang P, Amer A, Vaulks A, Pathan S, Abu Laban AMB. (2026) · DOI: 10.7759/cureus.107816

## 임상 시나리오

Assessing for Infectious MononucleosisRecognizing the Classic Triad in Adolescents
The hallmark presentation involves fever, pharyngitis, and lymphadenopathy. Focus palpation on the posterior cervical and axillary chains, noting firm, tender, symmetrical nodes.

Splenomegaly is present in up to 50% of cases. Palpate gently below the left costal margin to avoid the risk of splenic rupture, a critical complication.

CautionAvoid administering amoxicillin or ampicillin; a diffuse maculopapular rash will develop in approximately 90% of patients with EBV infection, which is not a true allergy.

## 핵심 개념

- **Infectious Mononucleosis** — A clinical syndrome caused by the Epstein-Barr virus (EBV), characterized by the classic triad of fever, pharyngitis, and lymphadenopathy, commonly affecting adolescents and young adults.
- **Lymphadenopathy** — Enlargement of lymph nodes, which in infectious mononucleosis is typically symmetrical and involves the posterior cervical chain, often accompanied by axillary or inguinal node enlargement.
- **Splenomegaly** — Enlargement of the spleen occurring in approximately 50% of infectious mononucleosis cases, increasing the risk of splenic rupture; palpation should be performed gently.

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