血液培養でActinomyces naeslundiiを検出した頸部壊死性筋膜炎例

抄録

Bacteria of the genus Actinomyces are resident in the oral cavity (interdental spaces, plaques, tonsils, etc.) and these organisms become pathogenic when their environment becomes anaerobic. The predominant site of actinomycosis is the head and neck region, but cases of necrotizing fasciitis and septic shock are extremely rare. In addition, while in most cases, actinomycosis is caused by Actinomyces israelii, actinomycetes are difficult to identify by bacteriological culture.

We report the case of an 84-year-old woman who visited our hospital complaining of anterior cervical swelling and difficulty in breathing. Blood examination showed elevated levels of inflammatory markers, and CT showed a deep neck abscess and emphysema. Surgery was performed, and intraoperative examination revealed necrotizing fasciitis.

The patient went into transient cardiopulmonary arrest and a repeat CT showed worsening of the emphysema and abscess. The final diagnosis was necrotizing fasciitis and septic shock caused by some gas-producing bacteria. The surgery allowed diagnosis of the extensive necrotizing fasciitis in the neck. The condition was thought to be caused by Actinomyces naeslundii, which was detected on blood culture.

Actinomyces naeslundii has been identified in the head and neck region in only four cases in all, including one case in Japan and three cases overseas; thus, it is extremely rare, and ours may be the first case in which it was identified by blood culture.