Appendicitis differential diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Farwa Haideri [2]

Overview

Appendicitis must be differentiated from other causes of abdominal pain such as acute gastroenteritis and luminal obstruction. Age group can be another factor used to differentiate appendicitis.

Differentiating Appendicitis from other Diseases

• Appendicitis can be differentiated from other diseases that cause lower abdominal pain and fever like diverticulitis, inflammatory bowel disease, colon cancer, cystitis, and endometritis.

Diseases		Symptoms		Signs			Diagnosis		Comments
		Abdominal pain	Bowel habits	Rebound tenderness	Guarding	Genitourinary signs	Lab findings	Imaging
GI diseases	Diverticulitis	LLQ	Constipation Or Diarrhea	-	+	+	Leukocytosis	CT scan shows evidence of inflammation
	Appendicitis	LLQ / RRQ	Constipation	+	+	-	Leukocytosis	Ultrasound shows evidence of inflammation	Nausea & vomiting,decreased appetite
	Inflammatory bowel disease	LLQ	Bloody diarrhea	-	-	-	Leukocytosis		Colonoscopy and tissue sampling are recommended for differentiating between Crohn's disease and ulcerative colitis.
	Colon carcinoma	LLQ	Constipation	-	-	-	Serum carcino-embryogenic antigen  Low vitamin B12 Hypercalcemia	CT scan, x-ray and MRI used to show metastasis
	Strangulated hernia	LLQ	-	-	-	-	No specific tests	CT scan used to detect the hernia and to show if it is single or multiple
Gentiourinary diseases	Cystitis	LLQ	-	+	-	Suprapubic tenderness	Pyuria Presence of nitrites and leukocyte estrase	X ray is done to probe the suspicion of emphysematous cystitis. CT scan shows gas in the bladder in cases of emphysematous cystitis.
	Prostatitis	LLQ Groin pain	-	-	-	Tender and enlarged	Serum PSA elevated Leukocytosis Elevated CRP	CT scan shows edema and enlarged prostate Abscess may be observed
	Pelvic inflammatory disease	Bilateral	-	+	-	Purulent vaginal discharge	Nucleic acid amplification tests is the best laboratory test for PID.	Transvaginal utrasonography
Gynecological diseases	Endometritis	LLQ	-	+	-	+	No specific tests	Ultrasound is helpful to rule out other differential diagnosis such as pelvic abscess, thrombosis and masses	Vaginal discharge Vaginal bleeding
	Salpingitis	LLQ/ RLQ		+/-	+/-		Leukocytosis	Pelvic ultrasound	Vaginal discharge

• Since appendicitis presents as the general symptom of abdominal pain, appendicitis must be differentiated from other diseases and disorders causing similar pain and symptoms. This differentiation can be done according to four categories: surgical, urological, gynaecological, and medical.

Classification of acute abdomen based on etiology Presentation Clinical findings Diagnosis Comments Fever Rigors and Chills Abdominal Pain Jaundice Hypotension Guarding Rebound Tenderness Bowel sounds Lab Findings Imaging Common causes of Peritonitis Spontaneous bacterial peritonitis + Diffuse − − − − Hypoactive Ascitic fluid PMN>250 cells/mm³ Culture: Positive for single organism Ultrasound for evaluation of liver cirrhosis - Perforated gastric and duodenal ulcer + Diffuse − + + + N Ascitic fluid LDH > serum LDH Glucose < 50mg/dl Total protein > 1g/dl Air under diaphragm in upright CXR Upper GI endoscopy for diagnosis Acute suppurative cholangitis + + RUQ + + + + ± Acute cholangitis + − RUQ + − − − N Abnormal LFT Ultrasound shows biliary dilatation Biliary drainage (ERCP) + IV antibiotics Acute cholecystitis + RUQ + − − Hypoactive Hyperbilirubinemia Leukocytosis Ultrasound shows gallstone and evidence of inflammation Murphy’s sign Acute pancreatitis + Epigastric ± − − N Increased amylase / lipase Ultrasound shows evidence of inflammation Pain radiation to back Acute appendicitis + RLQ − + + Hypoactive Leukocytosis Ultrasound shows evidence of inflammation Nausea & vomiting, decreased appetite Acute diverticulitis + LLQ ± + − Hypoactive Leukocytosis CT scan and ultrasound shows evidence of inflammation Hollow Viscous Obstruction Small intestine obstruction − Diffuse − + ± Hyperactive then absent Leukocytosis Abdominal X ray Nausea & vomiting associated with constipation, abdominal distention Gall stone disease/Cholelithiasis ± − Volvulus - Diffuse - + - Hypoactive Leukocytosis CT scan and abdominal X ray Nausea & vomiting associated with constipation, abdominal distention Biliary colic - RUQ + - - N Increased bilirubin and alkaline phosphatase Ultrasound Nausea & vomiting Renal colic - Flank pain - - - N Hematuria CT scan and ultrasound Colicky abdominal pain associated with nausea & vomiting Vascular Disorders Ischemic causes Mesenteric ischemia ± Periumbilical - - - Hyperactive Leukocytosis and lactic acidosis CT scan Nausea & vomiting, normal physical examination Acute ischemic colitis ± Diffuse - + + Hyperactive then absent Leukocytosis CT scan Nausea & vomiting Hemorrhagic causes Ruptured abdominal aortic aneurysm - Diffuse - - - N Normal CT scan Unstable hemodynamics Intra-abdominal or retroperitoneal hemorrhage - Diffuse - - - N Anemia CT scan History of trauma Gynaecological Causes Fallopian tube Acute salpingitis + LLQ/ RLQ − ± ± N Leukocytosis Pelvic ultrasound Vaginal discharge Ovarian cyst complications and endometrial disease Torsion of the cyst - RLQ / LLQ - ± ± N Increased ESR and CRP Ultrasound Sudden onset sever pain with nausea and vomiting Endometriosis - RLQ/LLQ - +/- +/- N Normal Laproscopy Menstrual-associated symptoms, pelvic symptoms Cyst rupture - RLQ / LLQ - +/- +/- N Increased ESR and CRP Ultrasound Sudden onset sever pain with nausea and vomiting Pregnancy Ruptured ectopic pregnancy - RLQ / LLQ - - - N Positive pregnancy test Ultrasound History of missed period and vaginal bleeding Irritable Bowel Syndrome - Diffuse - - - - N Clinical diagnosis ROME III/IV criteria Pharmacologic studies based criteria - High dietary fiber Osmotic laxatives Antispasmodicdrugs Differentials to be considered In Children for appendicitis Mesenteric adenitis Meckel's diverticulum Intussusception Henoch-Schõnlein purpura, and lobar pneumonia References