Key Clinical Questions
What is the psychiatric differential diagnosis for patients with unexplained physical symptoms?
How can factitious disorder be differentiated from malingering?
What is conversion disorder, and how is this different from factitious disorder?
What are the best practices in the care of patients with somatic symptom and related disorders, conversion disorder, illness, and malingering?
Patients who present with multiple unexplained somatic symptoms pose a significant diagnostic and management challenge for any physician. Such patients are common in medical settings, representing approximately 1.5%-11% of primary care patients. In the general hospital setting, unique patterns of multiple unexplained somatic symptoms are classified as functional somatic syndromes; these include fibromyalgia, chronic fatigue syndrome, and irritable bowel syndrome. The most common presenting symptoms include chest pain, fatigue, headache, and dizziness; when such symptoms go unexplained the workup may involve unnecessary—and even dangerous—tests and procedures, as well as substantial medical cost. In primary care settings, multiple unexplained somatic symptoms are often co-morbid with psychiatric disorders (including major depressive disorder, generalized anxiety disorder, and panic disorder). The diagnostic criteria used in this chapter reflect the new categorization of disorders with prominent somatic symptoms in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5). Somatoform disorders (in the Diagnostic and Statistical Manual of Mental Disorders, 4th edition [DSM-4]), characterized by somatization disorder, undifferentiated somatoform disorder, pain disorder, conversion disorder, hypochondriasis, and body dysmorphic disorder, have been reorganized to somatic symptom and related disorders (in the DSM-5) to constitute: somatic symptom disorder, illness anxiety disorder, conversion disorder (functional neurological symptom disorder), psychological factors affecting other medical conditions, factitious disorder, other specified somatic symptom and related disorder, and unspecified somatic symptom and related disorder. Figure 229-1 provides a diagnostic algorithm to assist in the evaluation of a patient who presents with multiple unexplained somatic symptoms.
Diagnostic considerations in the patient with multiple unexplained symptoms.
GENERAL APPROACH TO THE PATIENT WITH MULTIPLE UNEXPLAINED SOMATIC SYMPTOMS
Table 229-1 outlines the major tenets of the approach to patients with multiple unexplained somatic symptoms. Considering the etiology of multiple unexplained somatic symptoms can be difficult, it may be helpful to prepare for a difficult interview (eg, a patient may provide a vague and/or elusive history, be argumentative, or be hostile). The specific approach to a given patient with multiple symptoms depends largely on the type of physical complaints with which the patient presents. However, regardless of the chief complaint, a thorough history is critical to the evaluation of true medical and neurologic illnesses; importantly, this interview should not be conducted while one is performing the physical examination. The medical history in such a patient helps the practitioner to determine if the patient is actually experiencing the symptoms reported, if the symptom has been exaggerated or feigned (eg, as in factitious disorder and ...