- Jessica Watson, academic clinical fellow, specialist trainee year 1 in general practice1,
- Alison Round, general practitioner2,
- William Hamilton, general practitioner and professor of primary care diagnostics3
- 1School of Social and Community Medicine, University of Bristol, Bristol BS8 2PS, UK
- 2Castle Place Practice, Tiverton EX16 6NP, UK
- 3Peninsula College of Medicine and Dentistry, Exeter EX2 4SG, UK
- Correspondence to: W Hamilton
Normal levels of inflammatory markers are valuable in ruling out a few specific conditions, notably polymyalgia rheumatica, giant cell arteritis, myeloma, and infection of hip revisions
Raised levels of inflammatory markers may be found in many other conditions, particularly infections, autoimmune conditions, and certain cancers. In these cases, they increase the probability of the condition being present, but additional information would be needed to be confident the disease is present or absent
Inflammatory markers are too non-specific to be a useful tool for diagnosing serious underlying disease and should rarely be used in this situation
In an incidental finding of raised levels of inflammatory markers, if history and examination yield no clues as to cause, it is reasonable to wait and see if symptoms develop. If levels are markedly raised (such as ESR >100 mm/h), the likelihood of disease is much higher, but history, examination, and focused investigations are usually sufficient to establish a diagnosis
A 72 year old man consulted a general practitioner colleague of ours last week complaining of a non-specific feeling of malaise for about three weeks, with mild headache and pain in his left knee. He has generalised moderate osteoarthritis, mainly affecting his back and both knees. Our colleague had found nothing relevant on examination and had ordered several blood tests. A full blood count and liver and renal function were normal, but the erythrocyte sedimentation rate was moderately raised at 35 mm/h.
What is the role of inflammatory markers?
Measurement of inflammatory markers has two main functions: to detect acute inflammation that might indicate specific diseases, or to give a marker of treatment response (we will not consider this second indication here). Measurement of inflammatory markers can also be used as a general, but non-specific, …