Patient was admitted from Outpatients at another hospital with the following:
- Cough with sputum
- Chest Pain
The fever had come on after a few days of feeling unwell. The patient had recently suffered with influenza and had overcome that illness in February 07. The fever was constant at about 38 degrees. There were no associated rigors. The patient denied sweats except in the last few days leading up to admission.
The cough was a new problem and was productive of yellow / dark coloured sputum. There was no history of haemoptysis. No recent weight loss, or loss of appetite. The patient was a long-term smoker (20/day for 20 years). There was no history of asbestos or TB exposure.
The patient also suffered with left sided chest pain which was worse on coughing and deep breathing. It was described as Sharp and the part could not take a deep breath. The was no description of cardiac chest pain.
The headache only occurred on coughing and was temporal in origin. No eye symptoms and no neck pain or stiffness.
The patient denied earache or throat pain.
The patient denied any leg pain or swelling and there was no complaint of breathlessness.
Previous History included Atypical Angina (angiography was normal) and some asthma.
Drugs included some inhaler therapy for asthma but no angina treatment.
Family history included lung cancer in a near relative.
Social history - patient was married with two children and was in employment in the electronics industry.
The was a pet dog at home but the patient denied allergies to fur.
On further questioning, the was no history of foreign travel or travel to onsen.
On examination the patient looked well. The temp was still 38 degrees, pulse 80 regular, BP 120/70, Sats 94% on room air, RR= 16/min
There was no evidence of lymphadenopathy.
Cardiovascular, Respiratory and Abdominal examination were entirely normal except for pain when pressing on the patient's anterior left upper ribs.
Legs were described as normal.
Blood results were all normal except for a raised CRP of 15. WCC, Neutrophil % were normal.
Differential Diagnosis based on Hx and Physical
- Drugs-- N/A
- Infection--Bacterial post-influenzal pneumonia (staph aureas), pneumococcal pneumonia, H. influenza, Atypical pneumonia e.g. mycoplasma. chlamydia; mycobacterial e.g. TB
- Endocrine: N/A
- Trauma: N/A
- Inflammatory: Wegener's Granulomatosis, SLE
- Neoplasia: Lung Cancer, Secondary Lung tumours
- Haematological: Leukaemia, Lymphoma, Pulmonary embolism
- Immunological: Goodpasture's syndrome
- Metabolic: N/A
The patient was examined it was generally normal apart from the superficial chest pain and it was also pointed out that the patient was quite thin.
Chest Roentogen examination was Abnormal. There was a definite discrete circular lesion in the Right Midzone and a possible second circular area in the Left Upper Zone.
The right lesion at its inferior aspect was more radio-dense (white) than the more radiolucent upper area. There was no fluid level present.
The doctors were asked to also examine the bones and one Resident pointed out a 'Moth-Eaten' Left posterior medial rib which was consistent with a pathological aetiology-- perhaps malignancy.
Differential Diagnosis at this Point
Probable Lung Abscess (despite no air fluid level) secondary to Staph aureus after recent influenza; possible anaerobic causation. TB as previously noted, was also considered.
With the presence of a rib lesion, there was a high suspicion of malignancy.
Lastly, Wegener's Granulomatosis also needed to be considered.
CT scan evaluation confirmed abscesses with thick walls and surrounding pneumonia.
No organisms had been grown on culture. The Echocardiogram performed to look for right sided infective endocarditis was Normal although IE could not be ruled out as a cause as the Modified Duke's Criteria show(see previous case of IE). The patient had not been asked if intravenous drugs were used illicitly.
Sputum examination revealed a polymicrobial flora but no specific infecting organism.
TB Ziel-Nielsen stains were negative on two samples.
Samples had also been sent for cytology.
The patient had been started on a second generation cephalosporin without anaerobic cover.
- PCR of sputum for TB, Skin PPD test, Lowenstein-Jehnsen Culture for TB (4-10 weeks wait for growth!)
- Add either Clindamycin iv or Metronidazole orally [good bioavailability] (see Sanford Guide 2006 under Lung Abscess)
- Consider bronchoscopy for obtaining brushings, BAL for microbiological analysis (bacteria, mycobacteria and fungi) and cytology and even abscess drainage if necessary
- ANCA test for Wegener's
- Immunoprecipitins for Cryptococcus
- Beta-D-Glucan for identifying presence of invasive fungal infection
- Isotope bone scan to rule in/out metastases in the event that the rib lesion is cancerous
The usual cause of lung abscess is from aspiration of anaerobic oral flora. The symptoms consist of fever, cough and dirty sputum. Rigors invariably do not occur in these patients.
Other causes include Staph and occasionally strep species. TB is another cause of lung abscess and should never be forgotten.
Fungal infections include cryptococcus, blastomyces, candida etc...
Atypical type organisms can occur from infections derived from infective endocarditis from the Right Heart in IV drug users.
Non-infective causes include lung malignancy.
Wegener's Granulomatosis results in a necrosis of lung tissue which may simulate lung abscess formation. However, this patient did not have joint symptoms, upper respiratory symtpoms or signs of renal impairment making it an unlikely cause of this disorder.