The patient with possible pneumonia

Community-acquired pneumonia (CAP) is part of a spectrum of lower respiratory tract infection (LRTI) and is commoner in the winter months and in more deprived populations. Despite modern antibiotics, pneumonia remains the second commonest cause of death in the UK after ischaemic heart disease. Streptococcus pneumoniae is the commonest confirmed microbiological cause of CAP, with Mycoplasma pneumoniae the second commonest during epidemic years. Although most patients with CAP will have lung crackles or bronchial breathing, distinguishing pneumonia from non-pneumonic LRTI can be difficult and chest X-ray confirmation is often required. All patients with CAP should undergo an initial severity assessment using the CURB-65 score before deciding on management, and respiratory rate is the most important clinical sign in assessing severity. Patients with severe pneumonia as defined by CURB-65 should receive broad spectrum intravenous antibiotics immediately, covering all suspected organisms, including Streptococcus pneumoniae. Those with no markers of severity can be treated safely at home with oral antibiotics. CRP should fall by 50% in 4 days; if not, reconsider the diagnosis and look for complications such as empyema. Clearance of the pneumonic consolidation takes on average 6 weeks and follow-up chest X-ray is usually unnecessary except in those at increased risk of malignancy, such as smokers and those aged over 65 years.