CASE PRESENTATION

A 14-year-old male, presented to the emergency department with high fever, general malaise, cough, chest, abdominal discomfort, myalgias, and headaches for 4 days prior to admission. Later, he developed diarrhea, vomiting, diminished appetite, and difficulty walking due to severe myalgias (more severe in the calves). His prenatal, natal, postnatal, and familial histories were unremarkable, and he lived in a rural location. The initial laboratory studies showed several abnormalities, including relative neutrophilia, a mild increase in creatinine and blood urea nitrogen, leukocyturia, microscopic hematuria, elevated inflammatory markers, myoglobin of 184.8 ng/mL with remaining normal cardiac enzymes, and CRP of 217.3 mg/L. Due to abdominal and chest pain, an ultrasound scan and ECG were performed. Only homogenous hepatosplenomegaly was found. Culture studies of blood and urine did not reveal any pathogenic and all serologies were negative. The patient was admitted for monitoring, additional care, and to clarify the etiology of his condition. Throughout hospitalization, his symptoms worsened, including headaches, hemoptysis, and desaturation, prompting the introduction of supplementary oxygen. CT angiography was requested and revealed a tree-in-bud pattern, Centro acinar micronodularities, and minor ground-glass densifications throughout all lung lobes (Figures 1 & 2), which excluded pulmonary thromboembolism but raised the hypotheses of a multisystem inflammatory condition with pulmonary involvement or atypical pneumonia with systemic manifestations (including zoonotic etiologies such as Leptospirosis, Acute Q fever, Brucellosis, and Lyme disease). A complete analytical study with cerebrospinal fluid analysis and a search for atypical zoonotic etiologies were performed. Treatment with doxycycline was initiated, later combined with ceftriaxone due to pleocytosis in the cerebrospinal fluid (CSF) to cover the most likely atypical etiologies. Due to the clinical severity, with respiratory and neurological dysfunction, a single dose of immunoglobulin was administered for possible multisystem inflammatory syndrome. After 7 days of endovenous therapy, clinical improvement was observed, and subsequent evaluations showed decreasing inflammatory markers and negative CSF cultures, thus he was discharged, totally asymptomatic, on oral doxycycline (for 14 days). Following hospitalization, a urine PCR was positive for Leptospira, and because he remained clinically stable and already completed 7 days of doxycycline, antibiotherapy was discontinued.

DISCUSSION

This is a classic case of pulmonary hemorrhagic involvement in a patient who had no other symptoms of Weil's disease [2-4]. During acute illness, seronegativity has been associated with cross-reactive antibodies. To diagnose leptospirosis in such cases, molecular techniques such as real-time PCR can be used [5-8]. This is because Leptospira DNA can be detected in blood during the initial bacteremic phase of the illness, and in cerebrospinal fluid and urine a few days after the onset of symptoms [9]. Most cases of leptospirosis have a self-limited course without antimicrobial therapy [4,9]. However, some patients may experience severe complications that can lead to morbidity and mortality. For hospitalized children penicillin (250 000-400 000 units/kg/day, divided into 4-6 doses, maximum 6-12 million units/day, intravenously), doxycycline (4 mg/kg/day, divided into 2 doses, maximum 200 mg/day, intravenously), or ceftriaxone (80-100 mg/kg/day, once daily, maximum 2 g/day) can be given. The literature also mentions azithromycin, which is active against different zoonoses, however it should be considered in outpatient instances rather than moderate to severe disease. Severe illness may require supportive care such as fluid-electrolyte therapy, blood products, ventilatory support, and renal replacement therapy. In adult patients, corticosteroids may be administered when there is pulmonary involvement and vasculitis [10-12]. Our patient received supportive care and was treated with doxycycline, resulting in resolution of both clinical and laboratory findings.