Munchausen Syndrome Workup

• The medical assessment of patients with chronic factitious disorder is analogous to the task of piloting an airplane through dense clouds. Under those flying conditions, it is important for pilots to follow the basic rules of flying and to trust their navigational instruments. Pilots who depart from these procedures and rely instead on their own inner sense of direction and orientation are at risk for a bad—if not disastrous—outcome. Similarly, physicians who encounter patients they cannot diagnose and who do not respond to the usual treatments can experience a similar feeling of panic and disorientation.

  • When this occurs, the physician should (1) follow the basic procedures for responding to the patient's signs and symptoms, (2) trust the reliability and validity of the medical tests that he or she performs, and (3) respect base-rate information about the prevalence of various diseases that must be excluded. Cases abound in which tests have been needlessly repeated, invasive procedures performed without adequate justification, or medications prescribed with such apparent zeal that iatrogenic problems actually come to dominate the clinical picture.
  • Patients with Munchausen syndrome use several techniques to disrupt the physician's usual practices. Typically, they exploit the clinician's fear of overlooking a rare, life-threatening disease. Simultaneously, they play to the clinician's fascination with rare and inscrutable medical problems. The patient with Munchausen syndrome understands the appeal of a medical mystery and the personal satisfaction, notoriety, and esteem that the physician experiences when he or she solves one. These factors combine to cause the physician to depart from standard procedures and to overlook more benign explanations for the patient's signs and symptoms.
  • Paradoxically, patients with Munchausen syndrome can also disrupt the physician's usual practices by persuading the physician to forego basic diagnostic procedures. Striking evidence of this phenomenon is noted in reports of patients who have successfully feigned diseases such as AIDS with Kaposi sarcoma and malignancies such as breast cancer. In both of these real-life examples, definitive tests were available to establish the presence of these diseases, but they were not performed because the patients' persuasive but false medical history, perhaps combined with their physical appearance, led to the mistaken assumption that the tests were unnecessary. Doctors may also erroneously believe that the ailment under consideration could not possibly be feigned or self-induced.
• Laboratory tests may be particularly helpful in identifying patients with Munchausen syndrome. Because many of these patients have a medical background, they often know the routine tests performed for a particular symptom presentation.

  • For example, a patient with anemia would anticipate that routine blood work would not include screens for the anticoagulants he or she has ingested, thus prolonging the medical or surgical investigation as the professionals search for the elusive etiology, such as unexplained hematuria or hematochezia.
  • The number of other ways in which patients have used tests and test results to mislead doctors is staggering. Several examples illustrate the range. Patients commonly self-inject insulin to create a baffling, tenacious, and dangerous hypoglycemic state. Before a diagnosis of insulinoma is made, doctors can expose the ruse by assessing whether or not the C-peptide level is compatible with the insulin level. High insulin levels combined with low C-peptide levels indicate factitious hypoglycemia.
  • Patients can create alarming laboratory evidence of proteinuria simply by adding a drop of egg white (a pure protein) to their urine specimens. A small amount of blood, perhaps added to a stool specimen or swallowed prior to endoscopy, appears as conclusive evidence for gastrointestinal pathology. The presence of unexplained puncture sites, especially in odd areas (eg, base of the tongue) can provide very compelling evidence of such dissimulation.
  • Conversely, laboratory test results may be inconsistent with the claimed illness, such as a lack of an elevated WBC count or left shift in an apparent case of sepsis or necrotizing fasciitis. Bacterial cultures may grow an overly wide variety of enteric flora when taken from infected sites distant from the pelvic or groin area because the patient has contaminated the wound with feces. Intractable diarrhea or vomiting may be missed unless the physician specifically asks laboratory personnel to assess for agents such as phenolphthalein or ipecac.
  • Some patients enter the nurses' station or access the vital-sign clipboards outside their doors and directly change laboratory values from normal to abnormal. They may present the doctor with letters from colleagues purporting to verify laboratory pathology, but a follow-up call reveals that the letterhead paper was stolen and a worrisome report was typed by the patient. Of course, self-induced but real illnesses (eg, extreme lead poisoning created by drinking water in which lead-based items were boiled) show corresponding authentic laboratory analyses that compel emergency treatment.

Imaging studies may be useful in diagnosing Munchausen syndrome. They may be particularly useful in cases in which the patient presents with a well-established medical problem of the type that can be easily imaged (eg, inoperable malignancies, cardiovascular accidents). In these cases, errors are made by eschewing these tests to spare the patient the expense or inconvenience of repeating tests that have already returned positive indications of disease. For many patients with Munchausen syndrome, the use of imaging studies becomes part of the search for an explanation for their puzzling signs and symptoms.

• Medical personnel should base testing on a well-considered and prioritized differential diagnosis. The performance of any procedures should be approached very conservatively if suspicions arise (eg, the patient has the "road-map" abdomen caused by scars from prior exploratory operations). Tests should not be needlessly repeated in the misguided hope that diagnostic pathology will suddenly emerge.
• Strongly subjective tests, such as electromyelography and nerve conduction velocity tests, should be understood as almost never definitive in isolation. An occasional positive finding, likely whenever anyone is subjected to extremely extensive and repeated testing, should not be misinterpreted. Clinicians should remember that each intervention poses a risk of iatrogenic complications that only complicate the picture. Indeed, such complications have frequently led to malpractice actions against physicians.