급성 설사 (1) 메커니즘/치료

급성설사 = 설사 <4wk

 

설사의 양상이 비염증성인지 염증성인지 판단하자. 

비염증성 설사는 위장관의 세포가 파괴되거나 균이 침입하지 않고 secretory mechanism이나 nervous system가 영향받기 때문에 혈변/발열이 없고 대변에서도 백혈구가 검출되지 않는다. 염증성 설사는 반대로 혈변/발열/복통이 있고 대변에서 백혈구가 검출된다.

설사 치료의 기본은 fluid & electrolyte replacement이다. 대부분의 케이스에서 정확한 진단은 필요하지 않거나 치료에 영향을 주지 않는다.

History taking, stool examination, evaluation of dehydration severity를 진행한다. 임상증상에 따른 치료는 다음과 같다.

 

Mechanism

• Adherence(유착):
  • V.cholerae: small intestinal enterocyte brush border에 유착
• Exotoxin
  • Enterotoxin: watery diarrhea -> acting directly on secretory mechanism in the interstinal mucosa

Ex): cholera -> increases Cl- secretion, decreases NA+ absorption -> loss of fluid / diarrhea

• Cytotoxin: destruction of mucosal cells and associated inflammatory diarrhea
• dysentery(이질): bloody stools containing inflammatory cells

Ex: shigella, vibrio parahaemolyticus, clostridium difficile,

• Neurotoxin: central or peripheral nervous system -> 주로 host 외부에서 만들어진다. 따라서 섭취후 곧바로 증상이 발생한다. 잠복기가 짧다.

Ex: staphylococcal and bacillus cereus toxin / CNS를 자극해 구토를 유발한다.

• Invasion
  • Mucosal epithelial cell invasion, intraepithelial multiplication, subsequent spread to adjacent cell
• Penetrate
  • Salmonella & yersinia -> penetrate intact interstinal mucosa, peyer's patch와 intestinal lymph node에서 증식후 혈액으로 퍼짐 (dissemination)