Case presentation
A 13-month-old male presented to our pediatric emergency department (ED) in early April 2020 with the chief complaint of fussiness, decreased appetite, and fever for five days. His mother reported that there was no resolution of his fever despite the use of antipyretics. At the presentation time, his mother denied cough, runny nose, ear pulling, shortness of breath, rash, vomiting, or diarrhea. She reported no recent travel nor sick contacts at home. Social history was remarkable for crowded and close living conditions, with five other family members sharing a two-bedroom apartment. The patient remained isolated at home since the pandemic began, but other family members had been out of the house for groceries. 
He was nontoxic on physical exam, appearing but fussy and febrile with a temperature of 102.7°F (Table 1). Physical exam was remarkable for dry, cracked lips with fissuring along the vermilion border and labial mucosa. His mucous membranes were dry, and there was pharyngeal erythema without exudates or tonsillar hypertrophy. The chest was clear to auscultation bilaterally. The patient had no conjunctivitis, lymphadenopathy, hepatosplenomegaly, nor edema or rash on the trunk, hands, and feet. 
Table 1  Vital signs of the patient on admission
Vital signs  Patient  Normal range for age
Temperature  102.7° F  95-100.3° F
Heart rate  172 beats per minute  80-130 beats per minute
Respiratory rate  32 breaths/min  40-60 breaths/min
Oxygen saturation on room air  98%  94-100% Laboratory findings showed a negative respiratory viral panel, a normal complete blood count (CBC) with lymphocytic predominance (Table 2), elevated C-reactive protein (CRP) of 25.81 mg/dL. The comprehensive metabolic panel (CMP) revealed metabolic acidosis with a normal anion gap with ketones present in the urinalysis. We obtained blood and urine cultures, and the patient was admitted and started empirically on ceftriaxone, antipyretics, and intravenous fluids. 
Table 2  Complete blood count of the patient
WBC - white blood cells; RBC - red blood cells; Hgb - hemoglobin; Hct - hematocrit; MCV - mean corpuscular volume; MCH - mean corpuscular hemoglobin; MCHC - mean corpuscular hemoglobin concentration; RDW - red cell distribution width
Complete blood count  Result  Reference range (for patient age)  Unit
WBC  7.7  6.0-17.5  x 109/L
RBC  4.46  3.8-5.4  x 10¹²/L
Hgb  11.4  13.1-15.5  g/L
Hct  35  39-47  L/L
MCV  77  72.0-88.0  fL
MCH  26  26-34  ρg
MCHC  329  320-360  g/L
RDW  12.9  11.5-16.0  %
Platelet  357  130-400  x 109/L
Neutrophil  2.5  1.5-8.5  x 109/L
Lymphocytes  3.9  3-13.0  x 109/L
Monocytes  1.1  0.1-1.9  x 109/L
Basophils  0.2  0.0-0.3  x 109/L
Eosinophils  0  0.0-1.5  x 109/L Due to persistent fever, a chest X-ray (CXR) was ordered, which showed bilateral interstitial infiltrates more prominent on the right peri-hilar area, which could represent atypical pneumonia (Figure 1). Urine and blood cultures were negative. However, the severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) polymerase chain reaction (PCR) was positive 24 hours after admission to the hospital. The patient was subsequently started on azithromycin for clinical suspicion of atypical pneumonia related to COVID-19, correlating with the CXR findings. The fever subsided after the first day of antibiotics, and the cheilitis improved during the admission. The patient was discharged home with isolation guidelines and completed five days of azithromycin and seven days of amoxicillin clavulanate for suspected clinical pneumonia. 
Figure 1  Portable CXR: bilateral interstitial infiltrates more prominent on the right perihilar area, which could represent atypical pneumonia
CXR - chest X-ray