Appendicitis: Difference between revisions

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==Background==
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*'''Most common surgical emergency''' worldwide
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*Lifetime risk: ~7-8% (peak incidence ages 10-30)
{{AdultPage|appendicitis (peds)}}
*Pathophysiology: luminal obstruction (fecalith, lymphoid hyperplasia, rarely tumor) → bacterial overgrowth → wall inflammation → ischemia → perforation
<translate>
*Perforation risk increases with time: ~2% at 24 hours, increasing to ~50% by 72 hours
*Atypical presentations common in: children, elderly, pregnant women, immunocompromised


==Background== <!--T:112-->
==Clinical Features==
===Classic Presentation===
*Periumbilical pain migrating to RLQ over 12-24 hours (migration is most specific historical feature)
*Anorexia (nearly universal; absence should raise doubt)
*Nausea, vomiting (usually after onset of pain)
*Low-grade [[fever]] (high fever suggests perforation/abscess)


<!--T:113-->
===Physical Exam===
[[File:Appendix locations.png|thumb|Drawing of colon with variability of appendix locations as seen from anterior view.]]
*McBurney point tenderness (1/3 distance from ASIS to umbilicus)
*Acute inflammation of the vermiform appendix
*Rovsing sign: RLQ pain with LLQ palpation
*Most common non-obstetric surgical emergency in pregnancy
*Psoas sign: RLQ pain with right hip extension (retrocecal appendix)
*Most common abdominal surgical emergency in patients <50
*Obturator sign: RLQ pain with internal rotation of flexed right hip (pelvic appendix)
*Most common between 10-30 years, but no age is exempt
*Rebound tenderness and guarding (peritoneal irritation)
*Most commonly caused by luminal obstruction by a fecalith
*Dunphy sign: increased pain with coughing
*There are no historical or physical exam findings that can definitively rule out appendicitis


===Atypical Presentations===
*Retrocecal appendix (~30%): flank or back pain, positive psoas sign, less peritoneal irritation
*Pelvic appendix: suprapubic pain, urinary symptoms, diarrhea
*Pregnant women: RUQ pain (displaced appendix); less peritoneal signs; higher perforation rate<ref>Mourad J, et al. Appendicitis in pregnancy: new information that contradicts long-held clinical beliefs. ''Am J Obstet Gynecol''. 2000;182(5):1027-1029. PMID 10819817</ref>
*Elderly: delayed presentation, less fever, higher perforation rate (~50%)
*Children <5: nonspecific symptoms; perforation common by presentation


==Differential Diagnosis==
*[[Mesenteric adenitis]] (children — viral)
*[[Ovarian torsion]], ruptured [[ovarian cyst]], [[ectopic pregnancy]]
*[[Crohn's disease]] (terminal ileitis)
*[[Diverticulitis]] (right-sided in Asian patients, cecal)
*[[Cholecystitis]], [[nephrolithiasis]], [[UTI]]
*[[Pelvic inflammatory disease]]
*Epiploic appendagitis, omental infarction
*[[Testicular torsion]]


{{RLQ pain DDX}}


==Evaluation==
===Labs===
*WBC: elevated in ~80% (but normal WBC does NOT exclude appendicitis)
*CRP: elevated; combined normal WBC + normal CRP has high NPV
*Urinalysis: mild pyuria/hematuria may occur (inflammation adjacent to ureter) — does not exclude appendicitis
*Pregnancy test in all reproductive-age women
*Lipase if epigastric component


==Clinical Features== <!--T:114-->
===Clinical Decision Rules===
*Alvarado Score (MANTRELS): Migration, Anorexia, Nausea, Tenderness RLQ, Rebound, Elevation of temp, Leukocytosis, Shift to left
**Score ≤3: low risk; 4-6: moderate; ≥7: high probability
*AIR Score (Appendicitis Inflammatory Response): incorporates CRP
*'''These scores help risk-stratify but do NOT replace clinical judgment'''


<!--T:115-->
===Imaging===
[[File:McBurney's point.jpg|thumb|Location of McBurney's point (1), located two thirds the distance from the umbilicus (2) to the right anterior superior iliac spine (3).]]
====CT Abdomen/Pelvis with IV Contrast (Test of Choice in Adults)====
*Sensitivity 94-98%, specificity 95%
*Findings: enlarged appendix > 6 mm diameter, periappendiceal fat stranding, appendicolith, wall enhancement
*Signs of perforation: abscess, extraluminal air, phlegmon
*Oral contrast generally NOT needed


====Ultrasound (First-line in Pediatrics and Pregnancy)====
*Sensitivity 86%, specificity 81% (operator dependent)
*Findings: non-compressible appendix > 6 mm, target sign, periappendiceal fluid
*If US equivocal in pediatrics: MRI preferred over CT to avoid radiation


====MRI (Alternative in Pregnancy)====
*Sensitivity 94%, specificity 97%
*Preferred over CT in pregnancy (no radiation)


==Management==
===Uncomplicated Appendicitis===
*'''NPO, IV fluids, pain control''' (analgesics do NOT mask peritoneal signs)
*Pre-operative antibiotics: cefoxitin 2g IV or ceftriaxone + metronidazole
*Laparoscopic appendectomy (standard of care)
*Antibiotics-first approach: emerging evidence supports nonoperative management with antibiotics alone for selected uncomplicated appendicitis (CODA trial)<ref>CODA Collaborative. A randomized trial comparing antibiotics with appendectomy for appendicitis. ''N Engl J Med''. 2020;383(20):1907-1919. PMID 33017106</ref>
**~30% failure/recurrence rate at 1 year
**Shared decision-making with patient and surgeon


===History=== <!--T:116-->
===Complicated Appendicitis (Perforated/Abscess)===
 
*Broad-spectrum antibiotics: piperacillin-tazobactam 3.375-4.5g IV OR ceftriaxone + metronidazole
<!--T:117-->
*Small phlegmon/abscess (<3 cm): antibiotics + interval appendectomy in 6-8 weeks
*Early on primarily malaise, indigestion, anorexia
*Large abscess (>3 cm): CT-guided percutaneous drainage + antibiotics + interval appendectomy
**Later patient develops [[Special:MyLanguage/abdominal pain|abdominal pain]]
*Peritonitis/sepsis: emergent appendectomy
***Initially vague, periumbilical (visceral innervation)
***Later migrates to McBurney point (parietal innervation)
*** <50% of patients have this typical presentation
*[[Special:MyLanguage/Nausea|Nausea]], with or with out emesis, typically follows onset of pain
*[[Special:MyLanguage/Fever|Fever]] may or not occur
*Urinary symptoms common given proximity of appendix to urinary tract (sterile pyuria)  
*Sudden improvement suggests perforation
*33% of patients have atypical presentation
**Retrocecal appendix can cause [[Special:MyLanguage/flank pain|flank]] or [[Special:MyLanguage/pelvic pain|pelvic pain]]
**Gravid uterus sometimes displaces appendix superiorly → [[Special:MyLanguage/RUQ pain|RUQ pain]]
 
 
 
 
 
===Physical Exam=== <!--T:118-->
 
<!--T:119-->
*McBurney's: maximal tenderness to palpation 2/3 of the way between umbilicus and right anterior superior iliac spine
*Rovsing sign (palpation of LLQ worsens RLQ pain)
*Psoas sign (extension of right leg at hip while patient lies on left side elicits abdominal pain)
*Obturator sign (internal and external rotation of thigh at hip elicits pain
*[[Special:MyLanguage/Peritonitis|Peritonitis]] suggested by:
**Right heel strike elicits pain
**Guarding
**Rebound
**Rigidity
 
 
 
 
 
===Clinical Examination Operating Characteristics=== <!--T:120-->
 
<!--T:121-->
{| class="wikitable"
|-
| Procedure
| LR+
| LR-
|-
| RLQ pain
| 7.3-8.4
| 0-0.28
|-
| Rigidity
| 3.76
| 0.82
|-
| Migration
| 3.18
| 0.50
|-
| Pain before vomiting
| 2.76
| NA
|-
| Psoas sign
| 2.38
| 0.90
|-
| Fever
| 1.94
| 0.58
|-
| Rebound
| 1.1-6.3
| 0-0.86
|-
| Guarding
| 1.65-1.78
| 0-0.54
|-
| No similar pain previously
| 1.5
| 0.32
|-
| Anorexia
| 1.27
| 0.64
|-
| Nausea
| 0.69-1.2
| 0.70-0.84
|-
| Vomiting
| 0.92
| 1.12
|}
 
 
 
 
 
==Differential Diagnosis== <!--T:122-->
 
</translate>
{{Abd DDX RLQ}}
<translate>
 
 
 
 
 
==Evaluation== <!--T:123-->
 
<!--T:124-->
[[File:Appendicitis_Jarrett_Subramaniam.gif|thumbnail|Dilated, non-compressible appendix with appendicolith and surrounding free fluid<ref>http://www.thepocusatlas.com/pediatrics/</ref>]]
[[File:AppendicitisMark.png|thumb|Peri-appendiceal fat stranding in the setting of acute appendicitis.]]
[[File:X-ray showing fecalith which has caused appendicitis.jpg|thumb|Fecalith (arrow) and stranding in the setting of acute appendicitis.]]
[[File:CAT scan demonstrating acute appendicitis.jpg|thumb|Dialated appendix and stranding in the setting of acute appendicitis.]]
 
 
 
 
===Appendicitis Risk Scores=== <!--T:125-->
 
</translate>
{{Alvarado scoring system}}
<translate>
 
 
 
 
 
===Labs=== <!--T:126-->
 
<!--T:127-->
*Abdominal panel
**CBC
***Normal WBC does not rule-out appendicitis
***Only 80% of patients will have leukocytosis with left shift<ref>Khan MN, Davie E, Irshad K. The role of white cell count and C-reactive protein in the diagnosis of acute appendicitis. J Ayub Med Coll Abbottabad. 2004;16(3):17-19.</ref>
**Chemistry
**Consider LFTs + lipase
**Consider coagulation studies (PT, PTT, INR), as a marker of liver function
*Urine pregnancy
*[[Special:MyLanguage/Urinalysis|Urinalysis]]
**Leukocytes will be present in 40% of patients<ref>Baird DLH, Simillis C, Kontovounisios C, Rasheed S, Tekkis PP. Acute appendicitis. BMJ. 2017;357:j1703. Published 2017 Apr 19. doi:10.1136/bmj.j1703</ref>
*Consider [[Special:MyLanguage/serum lactate|serum lactate]]
**Does not necessarily define level of severity (if appendicitis is present.)
**Can aid in trending effective resuscitation once the diagnosis is made.
*Consider CRP
**Normal CRP AND WBC makes appendicitis unlikely
 
 
 
 
 
===Imaging=== <!--T:128-->
 
<!--T:129-->
*Early surgical consultation should be obtained before imaging in straightforward cases
*Not universally necessary; consider in:
**Women of reproductive age
**Men with equivocal presentation
*Perforation may result in false negative study
*Imaging modalities
**[[Ultrasound: Abdomen|Ultrasound]]
***First choice for pregnant women and children
***Limitations: operator-dependent, difficult to visualize with obesity, gravid uterus, bowel gas, guarding, lack of patient cooperation
***Findings: noncompressible appendix >6mm in diameter, wall thickness greater or equal to 3 mm
***Other supportive findings: aperistalsis, distinct wall layers, target appearance in axial view, appendicolith, periappendiceal fluid, prominent echogenic periappendiceal fat
**CT
***First choice for adult males and nonpregnant women with equivocal cases
***Women derive the greatest benefit from preoperative imaging (lower neg appy rate)
***Contrast (both PO and IV) is unnecessary but typically ordered
**MRI
***When unable to identify appendix in children or pregnant women
 
 
 
 
 
==Management== <!--T:130-->
 
 
===Supportive Management=== <!--T:131-->
 
<!--T:132-->
#NPO status
#[[Special:MyLanguage/Fluid resuscitation|Fluid resuscitation]]
#[[Special:MyLanguage/Analgesia|Analgesia]]/[[Special:MyLanguage/antiemetics|antiemetics]]
 
 
 
 
 
===[[Special:MyLanguage/Antibiotics|Antibiotics]]=== <!--T:133-->
 
</translate>
{{Appendicitis Antibiotics}}
<translate>
 
 
 
 
 
===Surgery=== <!--T:134-->
 
<!--T:135-->
*Open laparotomy or laparoscopy
**Patients who present <72 hours after the onset of symptoms usually undergo immediate appendectomy
**Patients who present >72hrs and have perforated appendix may be treated initially with antibiotics, intravenous fluids, and bowel rest
 
 
 
 
 
==Disposition== <!--T:136-->
 
<!--T:137-->
*Admission
 
 
 
 
 
==Complications== <!--T:138-->
 
 
===Infection=== <!--T:139-->
 
<!--T:140-->
*Either a simple wound infection or an intraabdominal abscess
**Typically in patients with perforated appendicitis
 
 
 
 
 
===Recurrent appendicitis=== <!--T:141-->
 
<!--T:142-->
*Occurs in approximately 1:50,000 appendectomies <ref>Hendahewa R. et al. The dilemma of stump appendicitis - a case report and literature review. Int J Surg Case Rep. 2015; 14: 101-3.</ref>
*Typically caused by inflammation of the remaining appendiceal stump
**Can also be caused by a retained piece of the appendix not removed during surgery <ref>Boardman T. et al. Recurrent appendicitis caused by a retained appendiceal tip: A case report. The Journal of Emergency Medicine. 2019; 57: 232-4.</ref>
*Can present similar to primary appendicitis
*Treatment similar to that of primary appendicitis and likely requires surgical revision of the appendiceal stump or removal of retained tissue
*Delay in diagnosis and treatment can result in perforation and sepsis
 
 
 
 
 
==See Also== <!--T:143-->
 
<!--T:144-->
*[[Special:MyLanguage/Appendicitis (Peds)|Appendicitis (Peds)]]
 
 
 


==Disposition==
*Surgical consultation for all confirmed or highly suspected appendicitis
*Admit for surgical management
*If appendicitis suspected but imaging equivocal: observation with serial exams or repeat imaging in 6-12 hours
*Discharge with close follow-up only if alternative diagnosis confirmed and appendicitis reliably excluded


== Calculators ==
== Calculators ==
{{Alvarado_Calculator}}
{{Alvarado Calculator}}
 
==External Links== <!--T:145-->
 
<!--T:146-->
*[http://www.chop.edu/clinical-pathway/appendicitis-without-known-gi-disease-clinical-pathway CHOP Appendicitis Pathway]
*[https://www.acep.org/patient-care/clinical-policies/appendicitis/ ACEP Clinical Policy Statement]
*[http://www.emdocs.net/appendicitis-why-do-we-miss-it-and-how-do-we-improve/ emDocs - Appendicitis: Why Do We Miss It, and How Do We Improve?]
 
 


==See Also==
*[[Abdominal pain]]
*[[Appendicitis (peds)]]
*[[Abdominal pain (peds)]]
*[[Surgical abdomen]]


==References==
<references/>
*Di Saverio S, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. ''World J Emerg Surg''. 2020;15:27. PMID 32295644
*Bhangu A, et al. Acute appendicitis: modern understanding of pathogenesis, diagnosis, and management. ''Lancet''. 2015;386(10000):1278-1287. PMID 26460662
*Alvarado A. A practical score for the early diagnosis of acute appendicitis. ''Ann Emerg Med''. 1986;15(5):557-564. PMID 3963537


==References== <!--T:147-->
<!--T:148-->
<references/>
[[Category:GI]]
[[Category:GI]]
[[Category:Surgery]]
[[Category:Surgery]]
[[Category:ID]]
</translate>

Latest revision as of 09:55, 22 March 2026

Background

  • Most common surgical emergency worldwide
  • Lifetime risk: ~7-8% (peak incidence ages 10-30)
  • Pathophysiology: luminal obstruction (fecalith, lymphoid hyperplasia, rarely tumor) → bacterial overgrowth → wall inflammation → ischemia → perforation
  • Perforation risk increases with time: ~2% at 24 hours, increasing to ~50% by 72 hours
  • Atypical presentations common in: children, elderly, pregnant women, immunocompromised

Clinical Features

Classic Presentation

  • Periumbilical pain migrating to RLQ over 12-24 hours (migration is most specific historical feature)
  • Anorexia (nearly universal; absence should raise doubt)
  • Nausea, vomiting (usually after onset of pain)
  • Low-grade fever (high fever suggests perforation/abscess)

Physical Exam

  • McBurney point tenderness (1/3 distance from ASIS to umbilicus)
  • Rovsing sign: RLQ pain with LLQ palpation
  • Psoas sign: RLQ pain with right hip extension (retrocecal appendix)
  • Obturator sign: RLQ pain with internal rotation of flexed right hip (pelvic appendix)
  • Rebound tenderness and guarding (peritoneal irritation)
  • Dunphy sign: increased pain with coughing

Atypical Presentations

  • Retrocecal appendix (~30%): flank or back pain, positive psoas sign, less peritoneal irritation
  • Pelvic appendix: suprapubic pain, urinary symptoms, diarrhea
  • Pregnant women: RUQ pain (displaced appendix); less peritoneal signs; higher perforation rate[1]
  • Elderly: delayed presentation, less fever, higher perforation rate (~50%)
  • Children <5: nonspecific symptoms; perforation common by presentation

Differential Diagnosis

Template:RLQ pain DDX

Evaluation

Labs

  • WBC: elevated in ~80% (but normal WBC does NOT exclude appendicitis)
  • CRP: elevated; combined normal WBC + normal CRP has high NPV
  • Urinalysis: mild pyuria/hematuria may occur (inflammation adjacent to ureter) — does not exclude appendicitis
  • Pregnancy test in all reproductive-age women
  • Lipase if epigastric component

Clinical Decision Rules

  • Alvarado Score (MANTRELS): Migration, Anorexia, Nausea, Tenderness RLQ, Rebound, Elevation of temp, Leukocytosis, Shift to left
    • Score ≤3: low risk; 4-6: moderate; ≥7: high probability
  • AIR Score (Appendicitis Inflammatory Response): incorporates CRP
  • These scores help risk-stratify but do NOT replace clinical judgment

Imaging

CT Abdomen/Pelvis with IV Contrast (Test of Choice in Adults)

  • Sensitivity 94-98%, specificity 95%
  • Findings: enlarged appendix > 6 mm diameter, periappendiceal fat stranding, appendicolith, wall enhancement
  • Signs of perforation: abscess, extraluminal air, phlegmon
  • Oral contrast generally NOT needed

Ultrasound (First-line in Pediatrics and Pregnancy)

  • Sensitivity 86%, specificity 81% (operator dependent)
  • Findings: non-compressible appendix > 6 mm, target sign, periappendiceal fluid
  • If US equivocal in pediatrics: MRI preferred over CT to avoid radiation

MRI (Alternative in Pregnancy)

  • Sensitivity 94%, specificity 97%
  • Preferred over CT in pregnancy (no radiation)

Management

Uncomplicated Appendicitis

  • NPO, IV fluids, pain control (analgesics do NOT mask peritoneal signs)
  • Pre-operative antibiotics: cefoxitin 2g IV or ceftriaxone + metronidazole
  • Laparoscopic appendectomy (standard of care)
  • Antibiotics-first approach: emerging evidence supports nonoperative management with antibiotics alone for selected uncomplicated appendicitis (CODA trial)[2]
    • ~30% failure/recurrence rate at 1 year
    • Shared decision-making with patient and surgeon

Complicated Appendicitis (Perforated/Abscess)

  • Broad-spectrum antibiotics: piperacillin-tazobactam 3.375-4.5g IV OR ceftriaxone + metronidazole
  • Small phlegmon/abscess (<3 cm): antibiotics + interval appendectomy in 6-8 weeks
  • Large abscess (>3 cm): CT-guided percutaneous drainage + antibiotics + interval appendectomy
  • Peritonitis/sepsis: emergent appendectomy

Disposition

  • Surgical consultation for all confirmed or highly suspected appendicitis
  • Admit for surgical management
  • If appendicitis suspected but imaging equivocal: observation with serial exams or repeat imaging in 6-12 hours
  • Discharge with close follow-up only if alternative diagnosis confirmed and appendicitis reliably excluded

Calculators

Alvarado Score

Alvarado Score (MANTRELS)
Criteria Points No Yes
Symptoms
Migration of pain to RLQ +1 1
Anorexia +1 1
Nausea/vomiting +1 1
Signs
Tenderness in RLQ +2 1
Rebound pain +1 1
Elevated temperature (≥37.3°C / 99.1°F) +1 1
Labs
Leukocytosis (WBC >10,000/μL) +2 1
Left shift (>75% neutrophils) +1 1
Alvarado Score / 10
Interpretation
0–4 Low risk — Appendicitis unlikely. Consider other diagnoses.
5–6 Equivocal — Consider CT imaging or observation with serial exams.
7–8 Probable appendicitis — Surgical consultation recommended.
9–10 Very probable appendicitis — Operative management almost certain.

See Also

References

  1. ↑ Mourad J, et al. Appendicitis in pregnancy: new information that contradicts long-held clinical beliefs. Am J Obstet Gynecol. 2000;182(5):1027-1029. PMID 10819817
  2. ↑ CODA Collaborative. A randomized trial comparing antibiotics with appendectomy for appendicitis. N Engl J Med. 2020;383(20):1907-1919. PMID 33017106
  • Di Saverio S, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020;15:27. PMID 32295644
  • Bhangu A, et al. Acute appendicitis: modern understanding of pathogenesis, diagnosis, and management. Lancet. 2015;386(10000):1278-1287. PMID 26460662
  • Alvarado A. A practical score for the early diagnosis of acute appendicitis. Ann Emerg Med. 1986;15(5):557-564. PMID 3963537
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