Munchausen syndrome mimicking refractory subcutaneous abscess, a rare case reported

Dr Naoki Iwanaga at Department of Respiratory Medicine, Nagasaki University Hospital, Sakamoto, Nagasaki, Japan and colleagues have reported a rare case of Munchausen syndrome mimicking refractory subcutaneous abscess. The case has appeared in the Journal of Medical Case Reports.

Munchausen syndrome is a rare type of mental disorder mostly seen in young adults in which a person fakes illness and may cause self ham. The patient may lie about symptoms, make themselves appear sick, or make themselves purposely unwell. Rapid diagnosis and appropriate treatment of Munchausen syndrome are important not only for the patient but also for health care workers because a delay in diagnosis can worsen patients’ clinical outcomes, and result in a substantial medical cost.

A young and previously healthy 24-year-old Japanese woman, a nurse, presented with complaints of a refractory abscess on her left upper limb for 3 months. A physical examination on admission revealed low-grade fever and a subcutaneous abscess in her left forearm. Laboratory data suggested mild systemic inflammation and liver dysfunction, but no abnormalities of the immune system, including changes in the number of lymphocytes and neutrophils, neutrophil phagocytic capacity, and natural killer (NK) cell activity, were observed. A human immunodeficiency virus test was also negative. Multiple modalities, including positron emission tomography-computed tomography, failed to detect any cause and focus of infection except her left upper limb. Streptococcus mitis and Prevotella buccae were detected from the wound, but no microorganisms were detected in a blood culture.

The cellulitis promptly resolved; however, exacerbation of the subcutaneous abscess with polymicrobial bacteremia repeatedly occurred unexpectedly. Because of this puzzling clinical course, the possibility of self-injury was finally suspected. Three syringes with needles, with a turbid liquid, were found in our patient’s bag. Enterobacter cloacae and Enterococcus faecalis were detected in the liquid, and analysis via repetitive element sequence-based polymerase chain reaction determined that Enterococcus faecalis in the wound and syringe contents were genetically identical. She was diagnosed as having Munchausen syndrome and treated with the collaboration of a psychiatrist. She finally confessed that she had injected her own saliva and toilet water into the drip line and wound.

This case report is valuable in that it is the first case in which this syndrome was diagnosed by a genetic method. Munchausen syndrome should not be neglected as a possible cause of refractory and recurrent infection.