Background

COVID-19 is caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Fever is a common presenting symptom, along with cough, dyspnoea, myalgia and fatigue. Severe cases may lead to organ dysfunction and death.1

As with any infectious disease, one of the challenges with COVID-19 is to understand both the typical and atypical disease presentations. Atypical presentations carry the risk of going undetected for a longer duration, and in turn may lead to the spillover of the disease in a healthcare setting as well as the community.

Case presentation

A 27-year-old Indian man, with known type 2 diabetes, presented with a 5-day history of gradually progressive, moderate severity, generalised abdominal pain. The pain was accompanied by watery diarrhoea five to six times per day. He did not have any fever, sore throat, myalgias, influenza-like symptoms or shortness of breath. A review of systems was remarkable for dry cough of similar duration.

There was no recent history of travel and no sick contacts or animal exposure.

On initial presentation, he was not febrile, tachypnoeic, tachycardiac or hypotensive. Physical examination revealed a patient in distress due to abdominal pain. There was mild generalised abdominal tenderness, but no guarding, rigidity or rebound. The chest examination showed coarse bibasal crackles. The rest of the physical examination was unremarkable.

Initial work-up revealed normocytic anaemia, thrombocytopaenia and non-elevated inflammatory markers. Two repeated samples confirmed asymptomatic hyponatraemia. Liver enzymes, renal function and the endocrine panel were unremarkable. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) was the probable cause of hyponatraemia (table 1).

On the first day of admission, the patient developed high-grade fever. He was placed under isolation and screened for viral respiratory infections. The patient turned out to be positive for COVID-19.

Differential diagnosis

Given the patient’s chief complaint of abdominal pain with diarrhoea, gastroenteritis was the initial working diagnosis. There was no food intake from outside and no sick contacts. Stool analysis for ova and parasites was negative. Also, ELISA immunoassay for Clostridium difficile toxin came out negative. Stool culture was unrevealing. Stool PCR for SARS-CoV-2 was unavailable in the local hospital lab.

Pancreatitis was another differential, but lipase was negative. Atypical pneumonia was another possibility considering the minimal respiratory symptoms and bilateral chest X-ray findings (figure 1). The patient did not produce any sputum for culture, and two sets of blood cultures were negative. Due to hyponatraemia, Legionella pneumonia was considered; however, the urinary antigen was negative.

• Download figure
• Open in new tab
• Download powerpoint

Figure 1

Chest X-ray showing bilateral infiltrates, more on the bases. PA, posteroanterior.

Viral pneumonia was another diagnostic possibility for which a viral panel was sent, which included SARS-CoV-2 PCR, which eventually came back positive and hence confirmed the diagnosis of the novel coronavirus pneumonia (table 2).

Treatment

The patient was initially started on ceftriaxone, azithromycin and oseltamivir as empirical therapy for community-acquired pneumonia. After the tests for COVID-19 PCR from nasal swab came positive, the patient received chloroquine phosphate 250 mg two times per day, darunavir/cobicistat 950 mg daily and ribavirin 1200 mg two times per day for 14 days, based on local guidelines. Ribavirin 1200 mg two times per day was added to his antiviral regimen. The patient remained clinically stable throughout the hospital course until discharge.

Outcome and follow-up

The patient’s abdominal pain and diarrhoea resolved without any specific management. He did not require any ventilatory support during his stay. His SARS-CoV-2 PCR turned negative on repeat testing after 2 weeks and he was discharged home.