A 30‐year‐old man with depression and alcohol abuse presented with a 4‐day history of vomiting, productive cough, dyspnea, pleuritic chest pain, and intermittent fevers. His family noted slurred speech, confusion, and auditory and visual hallucinations for 1 day. His maternal grandmother had bipolar disorder. He drank 20 alcoholic beverages daily until one week prior to presentation. He denied a history of alcohol withdrawal. He endorsed tobacco and marijuana use but denied other illicit substances. Physical examination revealed fever to 38.0°C, tachycardia, left basilar crackles, picking at invisible objects, dysarthria, and difficulty with tandem gait. Laboratory results included a white blood cell count of 12.3 × 103/μL with absolute neutrophilia, sodium 126 mmol/L, AST 693 IU/L, and ALT 206 IU/L Urine toxicology was positive for cannabinoids. Serum calcium, TSH, alcohol, salicylate, acetaminophen, and ceruloplasmin levels were unremarkable. Chest radiograph revealed a left lower lobe infiltrate. CT of the head without IV contrast was unremarkable. CSF analysis was performed and unrevealing. Cultures of blood, urine, and CSF were obtained, and empiric antibiotics were initiated for presumed aspiration pneumonia. Evaluation for alcohol withdrawal was also enacted. MRI of the brain revealed a nodular focus of restricted diffusion within the splenium of the corpus callosum. Testing for Legionella pneumophila serogroup 1 urinary antigen returned positive. The patient's antibiotics were changed to levofloxacin with resolution of all symptoms. He was discharged in improved condition with instructions to abstain from alcohol and clean all aerosolized sources of water.
Legionella pneumophila is a gram‐negative bacillus that thrives in aquatic environments and may be inhaled by human hosts. Classically, patients present with respiratory illness and gastrointestinal symptoms such as diarrhea or vomiting. Central nervous system manifestations include headache, lethargy, dysarthria, ataxia, and auditory and visual hallucinations. Laboratory abnormalities such as hyponatremia and elevated aminotransferase levels are common but nonspecific. Legionellosis has been associated with lesions in the corpus callosum, but the differential diagnosis of these lesions is wide including epilepsy, multiple sclerosis, viral infections, and Marchiafava–Bignami disease among others. The pathophysiology and clinical significance of these lesions are unknown. Therapy includes fluoroquinolone or macrolide antimicrobial agents.
Because there are no pathognomonic features of legionellosis, initial evaluation of these patients can be challenging. This patient's presentation was complicated by his history of substance use as well as a personal and family history of psychiatric disease. For the hospitalist, this case demonstrates the importance of avoiding the anchoring heuristic and utilizing pattern recognition skills in order to make timely diagnoses and prevent mortality.
To cite this abstract:Houchens N. Cut Loose the Anchor: In Search of the Life Aquatic. Abstract published at Hospital Medicine 2013, May 16-19, National Harbor, Md. Abstract 445. Journal of Hospital Medicine. 2013; 8 (suppl 2). https://www.shmabstracts.com/abstract/cut-loose-the-anchor-in-search-of-the-life-aquatic/. Accessed March 31, 2020.