Community-acquired pneumonia (CAP) is a commonly treated disease and yet may present in unfamiliar ways that if missed may result in unnecessary testing, procedures, and potential harm.
Case
We present a 38-year-old male with no prior medical history who presented with 3 days of severe, cramping lower abdominal pain. This was intermittent, non-radiating, and exacerbated with movement. Associating symptoms were anorexia, constipation, fever, chills, nausea, and retching. He denied use of tobacco, alcohol, or recreational drugs.
Initial physical examination revealed a patient who was acutely ill and febrile (38.8°C), with pulse of 89 beats per minute, respiratory rate of 18 cycles per minute, blood pressure of 164/85 with orthostatic changes, and oxygen saturation (room air) of 98%. On abdominal examination, there was generalized abdominal tenderness with rigidity and guarding. The respiratory examination was benign. He was, therefore, worked up for an intra-abdominal cause of acute abdomen. Labs drawn showed white blood cell count 11300/µL without bands and hemoglobin of 12.9 g/dL. A 12-lead electrocardiogram (ECG) showed left ventricular hypertrophy, with significant ST elevation in the anterior leads, pathological q waves, T wave inversion in the lateral chest leads, and reciprocal changes in the inferior leads (Figure 1). Cycled troponins were negative. A computed tomography (CT) scan of the abdomen revealed normal abdominal viscera. However, a “mass-like opacity” in the right lower lobe of the right lung was reported (Figure 2).
A review of systems by the admitting team highlighted a history of intermittent productive cough with yellow sputum 1 day before presentation. Dullness to percussion over right posterior lower lung fields was also noted on repeat examination. A CT scan of the lung confirmed right lower lobe consolidation. Pneumonia became the diagnosis, with an atypical presentation of acute abdomen. The patient was admitted and treated with ceftriaxone and azithromycin. On day 2, lung crepitations became evident, which resolved before discharge. Serological and microbiological tests for legionella, mycoplasma, influenza, and blood cultures were negative. Transthoracic echocardiogram was unremarkable. He was discharged on day 5 to complete a week’s course of cefpodoxime.
Discussion
The typical presentation of pneumonia, irrespective of type, is that of respiratory symptoms with or without fevers and chills. Extrapulmonary symptoms are not usually not the predominant feature, and they usually proceed or occur with the respiratory symptoms. Acute abdomen as a presenting feature is uncommon (estimated 8% of cases in adults) and in the past has led to unwarranted emergent surgeries.1 With such presentations, respiratory symptoms may not become fully prominent until later in the illness.1– 3 With the uninhibited use of imaging, this may have become less common; however, even with such imaging, findings of pneumonia, such as in this case, can be incidental.2, 3
Cardiac complications presenting as ECG abnormalities can also be an uncommon presentation of pneumonia. These findings may be nonspecific ST changes; however, arrhythmias and other conduction abnormalities may result.4 It must also be highlighted that cardiac aberrations relating to pneumonia are not exclusive to atypical organisms alone.5 This, again, emphasizes the chameleon potential of community-acquired pneumonia. It also highlights in general the clinical acumen to place abnormal investigations such as these into context, rather than making a diagnosis based on the ECG alone.
In conclusion, the atypical presentations of pneumonia can be a diagnostic complexity that may be underreported.
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-Randol Kennedy, MD, Percy Adonteng-Boateng, MD, MPH
-This article originally appeared in the March issue of The American Journal of Medicine.
