ABC of Medically Unexplained Symptoms
ABC of Medically Unexplained Symptoms
Considering Organic Disease
David Weller1 and Chris Burton2
1Centre for Population Health Sciences, University of Edinburgh, Edinburgh, UK
2University of Aberdeen, Aberdeen, UK
Symptoms that appear to be functional will sometimes turn out to indicate serious illness
Premature closure of diagnostic reasoning and failure to consider the possibility of serious disease are the commonest serious diagnostic errors
Errors of judgement and system failures are far more common than errors due to lack of knowledge Introduction
Every patient who presents with a medically unexplained symptom (MUS) will eventually die, and many of them will consult a doctor with symptoms of their final illness. This sobering thought is the reason for this chapter, which aims to highlight particular problems and pitfalls when managing functional symptoms. A long history of MUS, particularly when combined with frequent attendance, can sometimes distract clinicians from one of their core tasks - diagnosing serious illness.
The chapter aims to answer three questions: how commonly does the diagnoses of MUS need to be revised; what are the factors associated with practitioner delay in diagnosing cancer; and what are the commonest diagnostic errors made by doctors.
This chapter does not list specific sets of red flags - they are described in individual chapters - but several themes are consistent across symptoms and body systems. Bleeding is never a symptom of MUS; similarly unintentional weight loss and night sweats need investigation - sometimes extensive investigation - to look for disease.
Symptom-specific recommendations for investigations are also included in the relevant chapters. However, as a rule of thumb, most non-trivial new symptoms in a patient who has not had recent investigations warrant basic blood tests: full blood count, renal, liver, thyroid and bone chemistry and inflammatory marker - with more added as clinically indicated. There is little evidence that deferring investigations is better or worse than carrying them out on the first occasion the patient presents with potentially significant symptoms.
How commonly does MUS turn out to be organic disease?
Surprisingly few studies have reported this. One small UK study found that in primary care, 10% of symptoms that have been present for several months and were thought to be MUS turned out to be due to organic disease. In secondary care the proportion is smaller, especially when the specialist concludes that there is a functional disorder rather than the diagnosis remaining ambiguous. A diagnosis of functional symptoms from a neurologist turns out to be wrong in only 2 - 3% of cases and similar proportions are probably seen by specialists in other disciplines.
New symptoms that are accompanied by anxiety are especially challenging, particularly when the patient has a past history of anxiety or panic disorder. Anxiety is one of a range of factors that may raise the practitioner's threshold of suspicion regarding new symptoms and which may inhibit timely recognition, diagnosis and referral. This kind of parallel presentation does not mean that recognition and treatment of the psychological disorder is unimportant, rather it acts as a reminder that the two can coexist.
What are the factors associated with practitioner delay in diagnosing serious illness?
Practitioner delay has been studied most thoroughly in relation to cancer diagnosis and the evidence for this has recently been exhaustively reviewed. The effect of patients' sociodemographic characteristics has a variable effect on practitioner delay.
Patient age is a factor in delayed cancer diagnosis, particularly for gastrointestinal cancers. Younge