A 34-year-old male, natural from Arequipa, Peru, with no previous medical conditions, presented with a seven-day history of progressive headache and photophobia, associated with fever, rash, weakness, myalgia and arthralgia. During physical examination on admission, patient showed irritability due to photophobia and high intensity headache, with 100.4  F temperature, erythematous macular and papular lesions on thorax and extremities; enlarged, superficial and tender lymph nodes in cervical, supraclavicular, axillar and inguinal areas; and hepatomegaly. No other significant alterations were found.
Viral encephalitis was presume. Brain magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) biochemistry were normal, with negative results on bacterial, fungus and viral etiologies by direct, culture and molecular research on CSF. Leukopenia (mild lymphopenia) with 13 % atypical lymphocytes was seen in the complete blood count. In addition, elevated values of lactate dehydrogenase, T troponin, creatine kinase - MB (CK-MB), aspartate and alanine aminotransferase, fibrinogen, ferritin, erythrocyte sedimentation rate (ESR) and beta-2 microglobulin were also present.
The suspicion of asymptomatic myocarditis with T troponin and CK-MB elevation was confirmed with cardiac MRI, which revealed subepicardic late enhancement and mild pericardial effusion with normal ventricular function (Fig. 1). In addition a cardiac computed tomography was perform, verifying normal coronary arteries. In the patient studied, cardiology prescribed nevibolol 2.5 mg per day. This therapy was initiated due to episodes of tachycardia unrelated to fever and chest pain that disappeared when the pulse decreased.
Immunoglobulin M (IgM) and G (IgG) for Toxoplasma gondii were slightly positive and negative respectively on the first examination. Other serology studies for Epstein Barr virus (EBV), cytomegalovirus (CMV), human immunodeficiency virus (HIV), hepatitis B virus, hepatitis C virus, measles, Brucella spp and syphilis were negative. Lymph node biopsy describe reactive mixed (follicular and paracortical) lymphoid hyperplasia. Microbiology and pathology studies on lymphoid tissue ruled out neoplasm, tuberculosis, fungal or other bacterial infections.
Nevertheless, protein chain reaction in lymph node tissue was positive for Toxoplasma spp, in concordance with a progressive increase in serum IgM Toxoplasma gondii observed during internship, confirming the diagnosis of acute toxoplasmosis with asymptomatic myopericarditis and possible encephalitis (Table 1). Therefore, trimethoprim/sulfamethoxazole (cotrimoxazole) 160/800 mg (2 pills) bid orally was added to the treatment and maintained for four weeks. During ambulatory consult progressive neutropenia forced change the anti-parasitic therapy to azithromycin plus clindamycin for the next final two weeks, under the suspicious of cotrimoxazole myelotoxicity. Clinical, laboratory and MRI improvement was seeing during the ambulatory controls, with no relapse of the symptoms after more than 12 months of follow up.