A case of suppurative tonsillitis as a complication of acute infectious mononucleosis

Abstract

Infectious mononucleosis (IM) is a benign lymphoproliferative disorder primarily caused by the Epstein–Barr virus (human gamma-herpesvirus 4) and most commonly affects 15–24-year-old individuals. Spontaneous splenic ruptures occur in 0.1% to 0.5% of patients with IM and can be life-threatening despite reports of suppurative processes involving the tonsils, such as intra-amygdala or peritonsillar abscesses. However, these rare complications can easily be misdiagnosed as acute suppurative tonsillitis caused by typical bacterial infection. This paper reports a case of a teenager with IM and concurrent suppurative tonsillitis, who was initially misdiagnosed with acute bacterial tonsillitis and failed to respond to antibiotic treatment. Examination confirmed IM combined with suppurative tonsillitis. Notably, his symptoms improved significantly after antiviral treatment. Therefore, we suggest that IM-complicating suppurative tonsillitis should be excluded when acute suppurative tonsillitis does not respond to antibiotic treatment and antiviral treatment strategies are urgently needed to avoid serious life-threatening complications.

Introduction

Acute suppurative tonsillitis is a common condition in otolaryngology, with Group A β-hemolytic streptococcus being the primary pathogenic bacterium. Penicillin and related antibiotics are routinely used to treat acute suppurative tonsillitis. However, 70% to 90% of tonsillitis cases are caused by viral infections, though suppurative tonsillitis induced by Epstein–Barr virus (EBV) infection is rare.^1‐3 Herein, we report a rare case of a teenage boy with acute infectious mononucleosis (IM) complicated by acute suppurative tonsillitis. Initially misdiagnosed as acute suppurative tonsillitis, the patient showed no significant improvement after treatment with penicillin antibiotics. Subsequent examinations suggested an EBV infection, and notably, his symptoms markedly improved following antiviral treatment. We have consulted with the institutional review board, and they exempted this case report from requiring formal institutional review board approval. We obtained consent to treatment and written information for this manuscript and potential future publications from the patient's legally authorized representative. Every effort was made to ensure the anonymity of the patient. The reporting of this study conforms to CARE guidelines. ⁴

Case report

A teenage boy presented to the otolaryngology department of People's Hospital of Xishuangbanna Dai Nationality Autonomous Prefecture on November 2023, with a one-week history of sore throat and worsening dysphagia. He reported a bitter taste in his mouth and a dry cough, without an increase in body temperature. A physical examination revealed bilateral tonsillar enlargement that crossed the midline, purulent secretions on the tonsillar surface (Figure 1A), and multiple bilateral subcervical and submaxillary lymph node enlargements. Laboratory test results were as follows: normal white blood cell count; lymphocyte percentage, 74.4% (reference value, 20% to 40%); lymphocyte absolute value, 5.9 × 10⁹/L (reference value, 1.39–3.19 × 10⁹/L); neutrophil percentage, 18.4% (reference value, 50% to 70%); neutrophil absolute value, 1.46 × 10⁹/L (reference value, 1.89–5.32 × 10⁹/L); alanine aminotransferase level, 183 U/L (reference value, 0 to 50 U/L); and aspartate aminotransferase level, 125 U/L (reference value, 0 to 50 U/L). Accordingly, the initial diagnosis was acute suppurative tonsillitis.

Figure 1.

(A) Bilateral tonsillar enlargement that crossed the midline, purulent secretions on the tonsillar surface. (B) Swollen tonsils and purulent discharge subsided.

The patient was administered penicillin at a dosage of 2.4 million units every 8 h, along with oral silibinin capsules at 35 mg three times a day, and inhaled budesonide suspension at 2 mL twice a day. After 3 days of treatment, there was no improvement in the pharyngeal symptoms. Respiratory viral pathogens, HIV, and dengue virus tests showed negative results. A culture of the purulent secretions from the tonsil surface showed no significant abnormalities. An abdominal ultrasound revealed splenomegaly, and serum real-time fluorescent polymerase chain reaction (PCR) indicated an EBV DNA level of 1870 IU/mL (reference value <500 IU/mL). Acute IM complicated with suppurative tonsillitis was considered. Penicillin was discontinued and switched to ganciclovir 0.25 intravenous drip, q12 h. A mouthwash of 20 mL hydrogen peroxide and 500 mL normal saline mixture was added. Four days later, the swelling of the tonsils and the purulent secretions had subsided (Figure 1B), and the patient's symptoms had significantly improved. Follow-up half a month after discharge showed that his symptoms had resolved without recurrence. This case highlights that conventional antibiotic treatment for acute suppurative tonsillitis may be ineffective and suggests that patients with tonsillitis should be investigated for EBV infection.

Discussion

The primary clinical manifestations of IM include fever, tonsillopharyngitis, and lymphadenopathy, and may be complicated by hepatosplenomegaly and a widespread rash.^5‐7 Uncontrolled EBV infection can trigger autoimmune responses in susceptible individuals, leading to a variety of symptoms and disease onsets, which may result in misdiagnosis. ⁸ In this report, the patient presented with a sore throat and a dry cough without fever. Therefore, it is challenging to diagnose the patient's condition based solely on clinical presentation. This case suggests that conventional penicillin antibiotic treatment for acute suppurative tonsillitis is ineffective, and serological testing for relevant viruses, including EBV DNA, should be conducted to investigate EBV infection.

Once IM is diagnosed, antiviral treatment should be initiated. In cases of impaired liver function, hepatoprotective therapy is also necessary. Although Streptococcus pyogenes is a common cause of suppurative tonsillar infections, it is rarely isolated in IM-associated tonsillar abscesses, making antibiotic treatment unnecessary in these cases. ⁹ Patients are advised to avoid contact sports or strenuous exercise for at least 4 to 6 weeks to minimize the risk of splenic rupture. All patients should be informed of the need for follow-up until symptoms resolve and they are permitted to resume physical activities. ⁶

In conclusion, given the impossibility of avoiding exposure to EBV, the most effective strategy for preventing EBV infection and IM would be the development of a safe, effective, and affordable EBV vaccine that confers lifelong immunity. ⁵

Conclusion

If suppurative tonsillitis does not show significant improvement after conventional antibiotic treatment, the possibility of EBV infection should be considered. To confirm an active EBV infection, beyond serological testing, EBV DNA should be detected in the patient's blood using PCR testing. Indeed, EBV viremia is a marker of active infection, ¹⁰ along with liver function tests and abdominal ultrasound, to rule out suppurative tonsillitis caused by EBV infection. If suppurative tonsillitis is confirmed to be caused by EBV infection, antiviral medication should be promptly initiated as part of the treatment.