38 HOW TO TREAT : MEDICALLY UNEXPLAINED SYMPTOMS
38 HOW TO TREAT : MEDICALLY UNEXPLAINED SYMPTOMS
8 DECEMBER 2023 ausdoc . com . au
‘ junk drawer diagnosis ’( see figure 3 ). 66 It contains disorders that are important but do not fit neatly into other diagnostic classifications , or they cross over several at the same time .
Without a language to describe the clinical dilemmas involved in treating patients with medically unexplained symptoms , the clinician is unable to manage them effectively . The clinician who is lost for words runs the risk of being lost for concepts that will help the patient , becoming “ empty-headed as well as empty-handed ”. 67
It is therefore helpful to think of medically unexplained illnesses as occupying several distinct categories . Factitious illness , the deliberate and conscious replication of symptoms for financial or psychosocial gain , is not discussed here — nor is Munchausen ’ s syndrome , which is an unconscious need to be ill , leading to feigning symptoms and signs .
The following classification is helpful to differentiate some common groups of medically unexplained illness .
The elusive illness
Diagnosis in general practice can be challenging . Rare diseases are surprisingly common ( see figure 4 ), and patients may present early in their illness when investigations may be negative and examination normal . 68
Consider a patient like Anna : a 45-year-old woman with fatigue , non-specific joint pain and some morning stiffness that is intermittent but severe enough to limit her capacity to work . There are no obvious clinical signs , and investigations to date have been normal . She clearly has a high risk of inflammatory arthritis , but it may be years before her illness is characterised .
Ben is a 55-year-old tradesman who has been experiencing disabling neurological symptoms since his third COVID-19 vaccination . He presents with dysarthria , unstable gait and profound fatigue . To date , his peripheral nerve studies have been normal , as is the brain MRI . Ben is clearly in a different category . Although we can categorise his illness as functional neurological symptoms , it seems likely that , in time , the cause of these symptoms may become clear as medical knowledge progresses .
Now consider Geedi , a 28-year-old refugee from Somalia , who presents with fatigue , intermittent severe joint pain and headaches . Standard pathology tests show iron deficiency anaemia ( see figure 5 ), but iron replacement does not resolve the pain . There are no obvious signs of infection . Geedi is likely to have a rare disease or at least a disease that is rare in our context . In all these cases , the GP is likely to know that an organic disease is probable even if it is difficult to find — hence the use of the term ‘ elusive illness ’.
The challenge for GPs lies in balancing the iatrogenic risk of investigation with the therapeutic risk of missing something important . Statistically , increasing the number of investigations increases the risk of false positives and a cascade of further investigations and treatments that are unnecessary and potentially harmful .
By continually investigating , we can also cause social iatrogenesis . We can convince the patient there
Figure 4 . Rare diseases are surprisingly common in general practice and can be difficult to detect and diagnose .
must be something medically wrong and lead them to invest in a career of medical attendance . 31
Detecting elusive illness requires a series of diagnostic strategies . These involve looking at the problem from multiple points of view . 69 Rare disease and diseases in their early stages can be difficult to diagnose . It is important to revisit assessment periodically and take a full history . It can be helpful to ask a student or registrar to present the situation as a long case .
Significant clusters of symptoms and signs are more easily recognised by search engines when expressed in formal medical terminology — for example , unilateral / bilateral , upper motor neuron / lower motor neuron , episodic / continuous . Increasingly , doctors supplement their formal literature searches with the use of public search engines ( Dr Google ). As conversational interfaces evolve , medical terminology is likely to improve the specificity of inquiries on consumer
Figure 5 . Microcytic and hypochromic red cell picture of iron deficiency anaemia .
Figure 3 . Diagnosis of medically unexplained illness is often likened to a junk drawer .
Associate Professor Erhabor Osaro / CC BY-SA 3.0 : bit . ly / 3Vi7qjp