The patient was a 27-year-old man who had suffered from pneumonia as a child and was a non-smoker and non-smoker. He was diagnosed with extrinsic bronchial asthma and allergic rhinoconjunctivitis with hypersensitivity to grasses and olive trees. He needed inhaled corticosteroids sporadically. After significant physical exertion (he was a costalero in a procession during a local festival and had slept very little) in the summer of 2003, he began to experience pain in the right hemithorax that sometimes radiated to the right upper limb and increased with deep breathing. Subsequently, he developed a fever and a feeling of dyspnoea, for which he went to the hospital emergency department. Clinical examination on admission revealed a poor general condition and a lesion in the scar phase on the abdominal wall that could correspond to a boil. Vesicular murmur was diminished at the right base. Cardiac and neurological examinations were normal. There were no organomegalies.
There was leukocytosis (from 12,000/cubic mm to 18,700/cubic mm) with neutrophilia, the rest of the haematological parameters being within normal limits. There was no eosinophilia. Creatinine increased during admission to 1.6 mg/dl and urea to 61 mg/dl. Other biochemical values were: total bilirubin: 2.19 mg/dl, direct fraction: 1.33 mg/dl, LDH: 687 IU/l, GOT: 61 IU/l; GPT: 111 IU/l, GGT: 521 IU/l, alkaline phosphatase 509 IU/l. Sedimentation rate reached 71 mm in the first hour. Serology for HIV and hepatitis B and C viruses were negative. Serial blood cultures were performed and were positive for susceptible Staphylococcus aureus methicillin.
Transthoracic echocardiography showed normal images without pericardial effusion. Ten days after admission, a warm, erythematous lesion appeared in the right parasternal region that disappeared on digitopressure and was about 5 x 5 cm. Fluid was aspirated from the lesion, the culture of which was also positive for methicillin-sensitive S. aureus. Ultrasound of the abdomen was normal. Chest CT scan showed a left pleural effusion with interstitial prominence. There were three small nodular images in the right upper lobe, left upper lobe and another subpleural image of less than one centimetre in size compatible with small staphylococcal abscesses (Fig. 1). The CT scan of the abdomen was normal, with no presence of adenopathy or fluid in the free cavity. The bone scan showed intensely increased osteogenic activity at the level of the sternal joint compatible with arthritis at that level. An MRI of the sternum was performed. There was gadolinium uptake at the joint of the manubrium with the sternal body, extending to the middle of the manubrium and the proximal third of the sternal body, with enlargement and uptake in the adjacent soft tissues, both anterior and posterior. These findings were compatible with arthritis at that level and highly suggestive of osteomyelitis. There were no signs of bone destruction. The clinical course was good with antibiotic treatment consisting of intravenous (IV) cloxacillin for 15 days at a dose of 2 g/6 hours and IV gentamicin for 7 days at a dose of 5 mg/kg/24 hours. He did not require intensive care at any time during his evolution. Subsequently, oral treatment with rifampicin (dose of 600 mg/24 h) and levofloxacin (dose of 500 mg, every 24 h) was continued for two months. The parasternal dermal lesion took five weeks to disappear. To rule out primary immunodeficiency, the patient underwent a screening test with the following results: normal complement levels, lymphocyte subpopulations and markers, granulocyte oxidative capacity and lymphocyte function (the latter with expression of activation markers in response to different stimuli). Protective levels for specific IgG against tetanus toxoid, Haemophilus By pneumococcal capsular polysaccharide. Slightly elevated levels of IgE and IgG4 with normality in the remaining immunoglobulins and IgG subclasses (IgE = 170 IU/l, normal range: 0-100 IU/l; Ig G4 = 3,910 mg/l, normal range: 80-1,400 mg/l). Isohemagglutinin titres could not be assessed due to lack of samples. This study was performed when the patient was discharged and two months after the onset of the disease.