Symptom To Diagnosis - Acute Diarrhea Flashcards
The DDX of acute diarrhea uses the pivotal point of presenting symptoms to organize diagnoses into 3 categories:
- Non infectious.
- Gastroenteritis.
- Infectious colitis.
Non infectious diarrhea:
Lack of constitutional symptoms.
Infectious diarrhea (gastroenteritis):
Presents with large volume (often watery) stool, constitutional symptoms, nausea and vomiting, and often abdominal cramps can be categorized as gastroenteritis.
Infectious colitis:
Presents with fever, tenesmus, and dysentery (stools with blood and mucus).
Many organisms can cause gastroenteritis and inflammatory diarrhea.
Non infectious diarrhea - General causes:
- Medications and other ingestible substances (some with osmotic effect).
- Mg-containing medications.
- Malabsorption.
- Medications causing diarrhea through non osmotic means.
Non infectious diarrhea - Medications and other ingestible substances (some with osmotic effect):
- Sorbitol (gum, mints, pill fillers).
- Mannitol.
- Fructose (fruits, soft drinks).
- Fiber (bran, fruits, vegetables).
- Lactulose.
Non infectious diarrhea - Mg-containing medications:
- Nutritional supplements.
- Antacids.
- Laxatives.
Non infectious diarrhea - Malabsorption:
- Lactulose intolerance.
2. Pancreatitis.
Non infectious diarrhea - Medications causing diarrhea through non osmotic means:
- Metformin.
- Antibiotics.
- Colchicine.
- Digoxin.
- SSRIs.
Infectious diarrhea (gastroenteritis) - General causes:
- Viral.
- Bacterial.
- Toxin-mediated.
Infectious diarrhea (gastroenteritis) - Viral causes:
Most common.
- Caliciviruses (Norovirus).
- Rotovirus.
Infectious diarrhea (gastroenteritis) - Bacterial (commonly food-borne):
- V.cholera.
- E.coli.
- Shigella.
- Salmonella.
- Campylobacter.
- Yersinia enterocolitica.
Infectious diarrhea (gastroenteritis): Toxin-mediated:
- S.aureus.
- C.perfringens.
- B.cereus.
- E.coli.
Infectious diarrhea (inflammatory colitis) - General causes:
- Bacterial.
2. Antibiotic-associated.
Infectious diarrhea (inflammatory colitis): Bacterial causes:
- Shigella.
- E.coli.
- Campylobacter.
- Salmonella.
- Y.enterocolitica.
Infectious diarrhea (inflammatory colitis): Antibiotic-associated:
- C.difficile.
- Klebsiella oxytoca.
- Non-C. difficile -related.
Acute diarrhea - Norovirus - Textbook presentation:
- Acute vomiting is usually the presenting symptom.
- Mild diarrhea begins after the vomiting.
- Mild abdominal cramping is common.
- Low-grade fever and dehydration are usually present.
- All symptoms resolve completely by 3 days.
Calicivirus (Norovirus, Sapovirus) account for what percentage of adult non bacterial gastroenteritis?
80%.
Norovirus infection most commonly occurs in?
Winter.
Norovirus - Transmission and attack rate?
Transmission may be person-to-person or food-borne.
50% attack rate.
MCC of food-borne infection:
Norovirus.
Norovirus - Incubation period:
1-2 days.
Home-made solution for patients with more significant volume depletion?
Mix 1 L of water with:
1/2 tea-spoon of salt.
1/4 teaspoon of baking soda.
8 teaspoons of sugar.
Antidiarrheals (loperamide) are safe and effective for patients with or without dysentery?
Without dysentery.
Using antidiarrheals in a patient with dysentery is not safe because they can:
- Cause prolonged fever.
- Cause toxic megacolon and perforation.
- Possibly increase the risk of HUS in patients with shiga toxin-producing E.coli (STEC).
Diet in adult non bacterial diarrhea:
- BRAT diet (banana, rice, applesauce, toast) is often recommended.
- Avoid dairy products.
S.aureus, C.perfringens, and B.cereus account for what percentage of food-borne infections?
<1% (!). (Viral causes account for about 60%).
MC bacterial and parasitic food-borne infections:
- Salmonella (38%).
- Campylobacter (33%).
- Shigella (16%).
- Cryptosporidium (5%).
- STEC (5%).
Gastroenteritis caused by Salmonella species:
- Subacute with nausea, fever, and diarrhea.
- Fever and nausea often resolve over 1-2 days while diarrhea persists for 5-7 days.
- . Patients usually have watery diarrhea with 6-8 bowel movements each day.
- Dysentery is possible.
- Bacteria remain in the stool for 4-5 weeks.
- Salmonella gastroenteritis may cause higher fevers than viral or preformed toxin disease.
Salmonella species cause 3 major types of disease:
- Diarrheal illnesses.
- Bacteremia with the potential for focal infectious complications.
- Typhoid fever.