What do MEDICALLY UNEXPLAINED SYMPTOMS (MUS) look like and is it a diagnosis?

Children with unexplained physical symptoms may present with a wide variety of problems, ranging from seemingly straightforward recurrent abdominal pain (RAP), headaches and other pains (in almost any part of the body), through difficulties with normal functioning such as dysphagia and difficulties with breathing, through to serious disturbances of neurological function, for example, disturbances of gait and motor function, sensory impairments and pseudoseizures. There have been many reviews in the past1–3 all commenting on the lack of good empirical research to support management.

Neither of the two major disease classification systems (International Classification of Diseases and Diagnostic and Statistical Manual of Mental Disorders) have specific diagnostic criteria for children and adolescents and so researchers and clinicians have to rely on adult criteria. The common diagnostic terms are summarised in box 1.

It is less clear if children with chronic fatigue syndromes (CFS) should be included here with other medically unexplained symptoms as the aetiology is uncertain and controversial. However, consensus criteria for diagnosis exist,6 symptoms are certainly currently unexplained, and what evidence there is for treatment suggests a similar approach to the other problems discussed here is effective.

How common are MUS?

Accurate prevalence figures are not available because of differing definitions of somatisation and measures used in research. The Ontario Child Health Study found negligible rates of somatisation in children under the age of 11 years, but in those aged 12–16 years 11% of girls and 5% of boys were identified as meeting criteria for somatisation disorder.7 Similar figures have been found in other studies.

In fact physical symptoms themselves are common. An investigation of >800 children aged 11–16 years for the lifetime prevalence of physical symptoms found that despite 95% reporting that their health had been good for most of their lives, girls reported having a median of six symptoms and boys five symptoms.8 10% of girls and 7% of boys had a lifetime prevalence of 13 or more symptoms. The most common symptoms were a lump in the throat (52%), dizziness (42%), heart pounding (40%), various aches and pains (joints, head, abdomen, chest: 30%), nausea (30%), blurred vision (26%) and a bad taste in the mouth (26%). There was an association between high reported symptoms and illness attitudes associated with mental distress, preoccupation with health and fears about illness.

The prevalence of RAP in 6-year-olds in the UK was reported as 25%,9 and a study of >6000 young people in the Netherlands (parental report age 0–3, self-report age 4–18) suggested that 54% had experienced pain within the previous 3 months, with one-quarter reporting chronic pain (recurrent or continuous pain for >3 months10).

In some children and young people, disorders that were initially categorised as ‘medically unexplained’ become attributable to specific organic diagnoses. It is difficult to put an exact figure to this as many of the better outcome studies report on samples that have excluded those with a subsequent organic diagnosis without giving numbers. In one adult study of 73 patients with conversion disorder, data were available for 56 patients of whom 11 had been given a subsequent diagnosis.11 Managing these presentations as medically unexplained while holding in mind the possibility of medically undiagnosed is a difficult balancing act for the clinician.

Possible aetiological factors

Lack of clarity around diagnostic criteria makes research into aetiology problematic. Reviews of the literature note that much of the evidence is from anecdotal accounts and presentations of case series and as a result all that can be reported are factors that can be correlated with MUS. In the child, physical illnesses often precede or coexist with such disorders. Psychiatric disorders are present in one-third to one half of children, with emotional disorders more common than conduct problems. The child's personality is often described as conscientious/obsessional or as sensitive, insecure and anxious, and difficulties with peer and social relationships are often reported.

In the wider family, parents are often described as being preoccupied with health issues, and are reported to have more psychiatric and physical symptoms than comparison families. Adverse life events, traumatic events such as abuse and experience of physical illness seem to be associated with somatisation.2 ,3

Is there an evidence base for treatment?

A systematic Cochrane review of psychological therapies for the management of chronic and recurrent pain (of the 29 studies included in the review, the majority were for headache (20) and abdominal pain (7)) concludes that psychological therapies (principally relaxation and cognitive behavioural therapy (CBT)) are effective treatments.12 However, the quality of the studies reviewed was not always high, and follow-up was often very short. Some of the better studies for RAP are from Sanders and colleagues,13 ,14 but the interventions delivered in most studies addressing RAP are broadly similar.

No methodologically sound controlled studies of the treatment of conversion disorder in children have been reported, but there are numerous case series and studies in the literature, with treatment approach often based on social learning theory and making use of concepts such as the sick role and abnormal illness behaviour.15 ,16

In chronic fatigue, a systematic review17 of adult and child studies of treatments for myalgic encephalomyelitis/chronic fatigue concluded that graded exercise therapy and CBT appear to reduce symptoms and improve function. Two child studies support this conclusion.18 ,19

Most of the evidence-based interventions for unexplained symptoms in children have multiple components but there is much overlap between different studies and from this it is possible to generate a list of possible evidence-based components of successful treatment—see box 2.

What practical steps can a paediatrician take in the outpatient clinic?

The essence of good and effective management involves acknowledgement of concerns, and acceptance of the seriousness of disability, coupled with alternative explanations of symptomatology and a rationale for the treatment offered. It is important to get the order right. For example, asking about potential stressors in the child's life before some kind of mutual acceptance of an alternative (to serious physical illness) explanation has been agreed can lead to disagreements. The emphasis here is on outpatient/community management although the principles outlined below would be equally applicable in an inpatient setting.

1. The initial assessment

The first step is always to carry out a thorough clinical assessment with a detailed history and examination which, as with all assessments, should include enquiry about recent life events and other possible stressors. Relevant investigations should be conducted promptly and if negative no further investigations conducted. If at this stage there is no indication of serious physical illness, this needs to be stated clearly. However, this needs to be coupled with a very clear acknowledgement that the symptoms experienced are ‘real’—parents can be very sensitive to suggestions that, as they see it, their child is being accused of ‘making things up’!

2. Provision of a rationale for physical symptoms in the absence of an organic cause

It is, therefore, essential that all clinicians are comfortable with providing alternative explanations for symptoms that accept they are real and problematic, while at the same time not the result of serious physical illness. This can often be done with reference to common, everyday stressful experiences. Most of us have experienced examinations, job interviews, driving tests, etc. Most of us would be insulted if it was suggested that the very real physical concomitants of anxiety that we experienced at the time were somehow made up. Physical symptoms without physical cause are in fact very common, so much so that they are part of our everyday language (butterflies in the stomach, my heart leapt, my mouth went dry, etc).

The aim here is to reassure about the absence of serious organic disorder while at the same time reminding parents and children that any number of physical symptoms can be caused by stress, tension or worry—experience suggests that the use of words like ‘psychological’ at this stage is unhelpful and is associated with making things up.

3. Detailed enquiry about possible stressors

This may have been covered in the initial assessment but in some families, enquiry about psychosocial causes can lead to difficulties, with parents expressing concerns that symptoms are thought not to be real or to be ‘made up’, that possible organic causes are being ignored, or that the child has ‘mental illness’. In these cases, it may be advisable to defer enquiry about psychosocial stressors until the family have been reassured by a thorough physical assessment (step 1), and some agreement has been reached about why a child might have real physical symptoms in the absence of serious organic disorder (step 2). It is then possible to ask a series of gentle questions about possible causes of stress in the child's life: ‘Is it possible your child might be worried about something and hasn't told you about it?’ It may be helpful to start away from home with questions about school, friends and bullying. ‘Have there been any recent changes at home or in the family?’ is probably better than ‘Are there any problems at home?’

Although this enquiry about stressors is essential it is common not to find any. If they are found they need to be addressed, although that will not always lead to symptoms disappearing. If no obvious stressors are found families need a very clear message that sometimes, whatever has started the symptoms (and it is useful to suggest it may have been a minor viral infection or some other possible minor physical cause), worry about what is causing them can keep them going. The fact that the family are in the paediatric clinic is testament to the amount of worry around.

4. The management plan

Now it is time to start addressing management plans. With or without external stressors, the emphasis needs to be on rehabilitation irrespective of cause. At its simplest this may mean the child being encouraged to resume normal activities despite the symptoms—particularly going to school and meeting with friends—with praise for doing this and a lack of attention for any further symptoms. If you and the parents have reached agreement about this new explanation for the symptoms this may be sufficient. It is essential to have enquired at the outset about school and social activities—the child who is at home all day with nothing to do but worry about symptoms is not going to improve rapidly, and this fact may inform part of your explanation about why symptoms have persisted.

With more engrained symptoms, a graded approach to rehabilitation may be required, and the involvement of physiotherapy and a set of gentle exercises that provide an ‘escape with honour’ may be helpful.

If at all possible involve the school and general practitioner in your management plan (although formal permission would be needed for school contact). If as a result of a well planned and executed consultation you have persuaded a family of the absence of serious disease, the possibility of worry as a symptom maintainer, and the need to resume normal activities you need to ensure that no one else inadvertently undermines this plan. It is not easy for a mother to insist on school attendance for a child who is still complaining of tummy ache. If the school then ring later in the day to say the child is unwell, and needs taking home it can seriously delay progress—school staff need to be part of the plan.

All of the above can and should be delivered by the paediatrician—this is the clinician with most knowledge of physical illness and most credibility if suggesting there is no serious disease. If this approach proves unsuccessful then a referral to local Child and Adolescent Mental Health Services (CAMHS) or to a paediatric health psychologist is indicated. This may be difficult if it has not been possible to agree about alternative explanations, one possible way forward would be to seek a joint consultation with a colleague from mental health services as a way of facilitating the referral.