Investigating recurrent respiratory infections in primary careBMJ 2009; 339 doi: https://doi.org/10.1136/bmj.b4118 (Published 12 November 2009) Cite this as: BMJ 2009;339:b4118
- Philip Wood, consultant immunologist1,
- Daniel Peckham, consultant respiratory physician2
- 1Department of Clinical Immunology, St James’s University Hospital, Leeds, LS9 7TF
- 2Department of Respiratory Medicine, St James’s University Hospital
- Correspondence to: P Wood
A 29 year old man presents to the surgery with a third episode of respiratory tract infection in three months, having had one admission to hospital with proved pneumococcal pneumonia five months ago. He is a previously well non-smoker who does not have asthma, any previous diagnosed chronic medical condition, or recent history of foreign travel.
He has no weight loss or night sweats. On examination he has bilateral basal crackles in the lungs, normal tympanic membranes, no facial tenderness, and no lymphadenopathy or splenomegaly. A full blood count is normal; random and fasting blood glucose, urea, creatinine, and liver enzymes are all normal, and urinalysis is negative for blood and protein. Sputum culture identifies the presence of Haemophilus influenzae. A chest radiograph is reported as normal.
What is the next investigation?
In 2007 the reported prevalence for acute respiratory infections in the United Kingdom was 1599/10 000 population, with peaks in early childhood and in people over 75 years of age. In contrast, the reported prevalence for pneumococcal pneumonia, and for pneumonia due to other causes, was 2/10 000.1 Upper respiratory tract infections are therefore common but are highly unlikely to indicate an underlying medical condition when they occur in isolation. There are no data on what constitutes a “normal” frequency of respiratory infections, and the characteristics of episodes of infection need to be considered.
Patients may have concerns over recurrent infections and their immunological competence. When infections are severe, persist despite standard therapy, recur after treatment is finished or at an unexpected frequency, or where the isolated organism is unusual within the clinical context, further investigation for underlying causes is warranted. Outside these situations, immunodeficiency is unlikely. …