Differentials
Coronavirus disease 2019 (COVID-19)
SIGNS / SYMPTOMS
Close contact with a suspected or confirmed case in the 14 days prior to symptom onset.
May be difficult to distinguish clinically from bacterial pneumonia. In addition to fever, cough and dyspnea, other common presenting symptoms include myalgia, fatigue and altered sense of taste and/or smell. Gastrointestinal symptoms are more common in children than adults. Evidence so far suggests a milder course of disease in children compared with adults.[88]
Auscultation of the chest may reveal inspiratory crackles, rales, and/or bronchial breathing in patients with pneumonia or respiratory distress.
Patients with respiratory distress may have tachycardia, tachypnea, or cyanosis accompanying hypoxia.
INVESTIGATIONS
Real-time reverse transcription polymerase chain reaction (RT-PCR): positive for SARS-CoV-2 RNA.
It is not possible to differentiate COVID-19 from other causes of pneumonia on chest imaging.
Pediatric inflammatory multisystem syndrome
SIGNS / SYMPTOMS
A rare, but severe condition, reported in children and adolescents approximately 2 to 4 weeks after the onset of COVID-19, likely due to a postinfectious inflammatory process. The syndrome has a strong temporal association with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. It shares common features with Kawasaki disease and toxic shock syndrome. Fever, shock, abdominal pain, vomiting, and diarrhea are common presenting features, frequently with a rash and cardiac involvement.
INVESTIGATIONS
No specific tests, but laboratory tests show raised inflammatory markers and evidence of cardiac inflammation in a majority of patients (elevated troponin and pro-B-type natriuretic peptide levels)
Abnormal ECG or echocardiogram findings
Real-time reverse transcription polymerase chain reaction (RT-PCR) may be positive for SARS-CoV-2 RNA.
Congenital heart disease
SIGNS / SYMPTOMS
Duct-dependent congenital heart disease may mimic early- or late-onset neonatal sepsis.
Differentiating signs include signs of congestive cardiac failure and left-sided, obstructive lesions (such as aortic coarctation or aortic stenosis), or profound, refractory cyanosis in cyanotic lesions (such as transposition of the great arteries or pulmonary atresia).
INVESTIGATIONS
Chest x-ray may reveal evidence of pulmonary edema and cardiomegaly in obstructive cardiac lesions.
Echocardiography will reveal detailed cardiac anatomy.
Noninfectious causes of systemic inflammatory response syndrome (SIRS)
SIGNS / SYMPTOMS
SIRS and organ dysfunction can result from multiple other stimuli, including cardiopulmonary bypass, trauma, pancreatitis, and burns.
It is very difficult to differentiate SIRS from sepsis; however, non-infectious SIRS will usually have a history of some other insult.
INVESTIGATIONS
Laboratory tests are indicated according to the likely underlying etiology (e.g., serum amylase if suspected pancreatitis).
CRP and serum procalcitonin can also be used to exclude infection.
Hemophagocytic lymphohistiocytosis
SIGNS / SYMPTOMS
May be primary (often associated with an inherited immunodeficiency) or secondary (e.g., triggered by a viral illness).
The clinical features often mimic sepsis, with fever, shock, and multiorgan failure in severe cases.
Diagnostic criteria include hepatomegaly, which may be a differentiating sign.
INVESTIGATIONS
Many overlapping features with sepsis.
Diagnostic criteria include pancytopenia, elevated ferritin and triglyceride concentrations, and hypofibrinogenemia.
Neuroleptic malignant syndrome
SIGNS / SYMPTOMS
Characterized by hyperthermia, generalized rigidity (which may be a differentiating sign), and autonomic dysregulation (e.g., sweating and labile blood pressure).
Onset of the syndrome occurs as an idiosyncratic complication to use of antipsychotic drugs.
INVESTIGATIONS
Elevated serum creatine kinase and myoglobin (and myoglobinuria) if rhabdomyolysis occurs.
Malignant hyperthermia
SIGNS / SYMPTOMS
Characterized by extreme hyperthermia, tachycardia, rigidity, and rhabdomyolysis after exposure to stimulating agent (usually anesthetic agents) in susceptible individuals.
INVESTIGATIONS
No specific differentiating tests in the acute stage, although creatine kinase and myoglobin will be elevated if rhabdomyolysis occurs.
Molecular genetic and tissue testing is available to confirm the diagnosis retrospectively.
Baclofen withdrawal syndrome
SIGNS / SYMPTOMS
Up to 72 hours after abrupt cessation of baclofen, a sepsis-like syndrome of spasticity, hyperthermia, hypertension, and rhabdomyolysis may develop.[89]
May occur in patients receiving intrathecal baclofen infusion by indwelling pump, if there is pump failure.
INVESTIGATIONS
No specific test, but there may be evidence of mechanical pump failure or catheter occlusion.
Elevated serum creatine kinase and myoglobin (and myoglobinuria) if rhabdomyolysis occurs.
Hyperammonemia
SIGNS / SYMPTOMS
Hyperammonemia and sepsis can be indistinguishable in neonates.
INVESTIGATIONS
Elevated ammonia level and genetic tests to identify the cause.
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