2024 ICD-10-CM Diagnosis Code K35.33

Acute appendicitis with perforation, localized peritonitis, and gangrene, with abscess

ICD-10-CM Code:
K35.33
ICD-10 Code for:
Ac appendicitis with perf, loc peritonitis, and gangr, wbscs
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Not chronic
Code Navigator:

Code Classification

  • Diseases of the digestive system
    (K00–K95)
    • Diseases of appendix
      (K35-K38)
      • Acute appendicitis
        (K35)

K35.33 is a billable diagnosis code used to specify a medical diagnosis of acute appendicitis with perforation, localized peritonitis, and gangrene, with abscess. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2023 through September 30, 2024.

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Abscess of appendix
  • Abscess of peritoneum
  • Acute appendicitis with peritoneal abscess
  • Acute appendicitis with peritonitis
  • Acute fulminating appendicitis
  • Acute fulminating appendicitis with perforation AND peritonitis
  • Acute gangrenous appendicitis
  • Acute gangrenous appendicitis with perforation AND peritonitis
  • Acute perforated appendicitis
  • Gangrenous appendicitis
  • Perforation of appendix
  • Pericecal abscess
  • Rupture of appendix
  • Rupture of intestine

Clinical Classification

Clinical CategoryCCSR Category CodeInpatient Default CCSROutpatient Default CCSR
Appendicitis and other appendiceal conditionsDIG009Y - Yes, default inpatient assignment for principal diagnosis or first-listed diagnosis.Y - Yes, default outpatient assignment for principal diagnosis or first-listed diagnosis.
Gastrointestinal and biliary perforationDIG006N - Not default inpatient assignment for principal diagnosis or first-listed diagnosis.N - Not default outpatient assignment for principal diagnosis or first-listed diagnosis.
Peritonitis and intra-abdominal abscessDIG016N - Not default inpatient assignment for principal diagnosis or first-listed diagnosis.N - Not default outpatient assignment for principal diagnosis or first-listed diagnosis.

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.


Inclusion Terms

Inclusion Terms
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
  • (Acute) appendicitis with (peritoneal) abscess NOS
  • Ruptured appendix with localized peritonitis and abscess

Index to Diseases and Injuries References

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

Replacement Code

K3533 replaces the following previously assigned ICD-10-CM code(s):

  • K35.3 - Acute appendicitis with localized peritonitis

Patient Education


Appendicitis

The appendix is a small, tube-like organ attached to the first part of the large intestine. It is located in the lower right part of the abdomen. It has no known function. A blockage inside of the appendix causes appendicitis. The blockage leads to increased pressure, problems with blood flow, and inflammation. If the blockage is not treated, the appendix can burst and spread infection into the abdomen. This causes a condition called peritonitis.

The main symptom is pain in the abdomen, often on the right side. It is usually sudden and gets worse over time. Other symptoms may include:

  • Swelling in the abdomen
  • Loss of appetite
  • Nausea and vomiting
  • Constipation or diarrhea
  • Inability to pass gas
  • Low fever

Not everyone with appendicitis has all these symptoms.

Appendicitis is a medical emergency. Treatment almost always involves removing the appendix. Anyone can get appendicitis, but it is more common among people 10 to 30 years old.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases


[Learn More in MedlinePlus]

Peritoneal Disorders

Your peritoneum is the tissue that lines your abdominal wall and covers most of the organs in your abdomen. A liquid, peritoneal fluid, lubricates the surface of this tissue.

Disorders of the peritoneum are not common. They include:

  • Peritonitis - an inflammation of the peritoneum
  • Cancer
  • Complications from peritoneal dialysis

Your doctor may use imaging tests or lab tests to analyze the peritoneal fluid to diagnose the problem. Treatment of peritoneal disorders depends on the cause.


[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - Code Updated, effective from 10/1/2022 through 9/30/2023
    • New Description: Acute appendicitis with perforation, localized peritonitis, and gangrene, with abscess
    • Previous Description: Acute appendicitis with perforation, localized peritonitis, and gangrene, with abscess
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.