We report the case of a 2 years and 9-month-old male child admitted in our clinic for prolonged fever, dry cough and shortness of breath. The disease onset was ~7 days before the admission with fever (39 C) and dry cough for which he was recommended symptomatic treatment by the general practitioner, but the symptoms worsened and thus he was admitted to our clinic.
The clinical exam at the time of admission revealed influenced general status, pallor, hyperemic pharynx, diminish breath sounds on the inferior right thorax, rales on the right lung field, tachypnea (45/min), oxygen saturation 85%, and tachycardia (154 beats/min).
The laboratory tests performed on the day of admission showed leukocytosis (Leu 23,890/muL) with neutrophilia (Neu 20,430/muL), anemia (Hemoglobin 10 g/dL), and elevated inflammatory biomarkers (C-reactive protein- CRP 303 mg/L, erythrocyte sedimentation rate- ESR 100 mm/h). The blood culture was negative. The thoracic radiography revealed pleural effusion raising the suspicion of inferior right pneumonia.
We initiated empirical treatment with 3rd class cephalosporin (Ceftriaxone) and Oxacillin, with outstandingly favorable evolution for ~7 days, with considerable improvement of clinical symptoms and inflammatory biomarkers (no fever, CRP 14.1 mg/L). Nevertheless, on the 8th day of admission the fever reappeared, and thus we repeated the laboratory tests noticing an increase in leukocytes (Leu 33,440/muL) and acute phase reactants levels (CRP 82.96 mg/L, ESR 140 mm/H), and a decrease in hemoglobin (6.6 g/dL), but the peripheral blood cells were normal. We repeated an emergency thoracic radiography which revealed a higher amount of pleural effusion, and thus a surgical drainage was performed inserting a pleural tube for 7 days (Figure 1). The aspect of the pleural fluid was clear, of yellowish color, and both cytology and culture were negative. We ruled out lung tuberculosis based on a negative exam of the fasting gastric fluid obtained by naso-gastric tube, but the pulmonology consult raised the suspicion of methicillin resistant Staphylococcus aureus recommending wide-spectrum antibiotics (Meropenem and Vancomycin). A blood transfusion was also administered. After ~5 days of treatment with the antibiotics mentioned above, the fever persisted and we found no improvement in laboratory parameters. Based on the initial outstandingly favorable evolution, we raised the suspicion of a possible superinfection, and we identified positive IgM for both MP and CP (IgM anti-MP 15 Index, IgG anti-MP 0.1 UA/mL, IgM anti-CP 42.3 U/mL, and IgG anti-CP 17.4 U/mL). We established the diagnosis of pneumonia caused by the coinfection with MP and CP, and we changed the antibiotic therapy on Levofloxacin for 10 days. On the 5th day of Levofloxacin we performed a thoracic computed tomography which showed lung window-encapsulated pleural effusion (Figures 2, 3), and we suppressed the thoracic drain tube. We discharged the patient on the 10th day of Levofloxacin with the recommendation to continue the treatment with Clarithromycin orally for 7 days.
We repeated the laboratory tests after 7 days of Clarithromycin and they were all within the normal ranges, as well as the thoracic radiography which revealed a diminished quantity of encapsulated pleural effusion (Figure 4). Therefore, we decided to diminish the dose of Clarithromycin at 1/3 of the initial for 1 month. Moreover, after ~1 month from the initial diagnosis, we noticed a seroconversion in terms of IgG for both MP and CP (IgG anti-MP 70 UA/mL, and IgG anti-CP 100 U/mL). The chest radiography performed after ~6 months revealed only a mild thickening of the inferior right pleura (Figure 5).