No abstract

A 12-month-old boy presented to our hospital with <24-h history of high-grade fevers and asymmetrical facial expression (day 1). This occurred on the background of a 5-day period of low-grade fevers and coryza.Physical examination showed peripheral facial nerve palsy (FNP) and acute otitis media (AOM) in the right ear (Fig. 1). He had no protruding auricle, pharyngitis, cervical lymphadenopathy, erythema, abdominal masses or abnormality of other nerves. Computed tomography of the head showed fluid accumulation in bilateral mastoid antra. White blood cell count was 13,700/μL (neutrophils 25.5%, lymphocytes 61.9%, monocytes 12.3%, basophils 0.3%) and C-reactive protein level was 10.81 mg/dL. The number of cells in cerebrospinal fluid (CSF) was 10/μL (mononuclear cells 10/μL, polymorphonuclear cells 0/μL), protein concentration was 13 g/dL, glucose level was 69 mg/dL. No bacteria were detected from blood or CSF cultures.We diagnosed FNP due to otomastoiditis and started the patient on cefotaxime (180 mg/kg/day), prednisolone (2.0 mg/kg/day) and acyclovir (45 mg/kg/day).FNP improved and fever resolved on day 3. The patient still had no pharyngitis, cervical lymphadenopathy or systemic erythema. However, the same day, we palpated an elastic, firm, smooth and painless mass in the left upper quadrant of the abdomen. We therefore conducted ultrasonography, revealing mild splenomegaly. In addition, white blood cell count increased to 20,800/μL, while C-reactive protein level decreased to 1.2 mg/dL. Atypical lymphocytes were seen in blood smears (12%). CD4/CD8 ratio was decreased to 0.4. We excluded the possibility of leukaemia or lymphoma by flowcytometry. These findings were most consistent with infectious mononucleosis (IM).