2024 ICD-10-CM Diagnosis Code A18.4

Tuberculosis of skin and subcutaneous tissue

ICD-10-CM Code:
A18.4
ICD-10 Code for:
Tuberculosis of skin and subcutaneous tissue
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Not chronic
Code Navigator:

Code Classification

  • Certain infectious and parasitic diseases
    (A00–B99)
    • Tuberculosis
      (A15-A19)
      • Tuberculosis of other organs
        (A18)

A18.4 is a billable diagnosis code used to specify a medical diagnosis of tuberculosis of skin and subcutaneous tissue. 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:

  • Acute tuberculous ulcer
  • BCG-induced lupus vulgaris
  • BCG-induced scrofuloderma
  • BCG-induced tuberculide
  • Cutaneous complication of BCG immunization
  • Cutaneous complication of BCG immunization
  • Cutaneous complication of BCG immunization
  • Cutaneous complication of BCG immunization
  • Cutaneous tuberculous gumma
  • Erythema induratum
  • Erythema nodosum caused by Bacteria
  • Infection due to Mycobacterium bovis
  • Infection due to Mycobacterium bovis
  • Infection due to Mycobacterium bovis
  • Infection due to Mycobacterium bovis
  • Infection following immunization
  • Infection following immunization
  • Infection following immunization
  • Infective panniculitis
  • Lobular panniculitis
  • Lupus vulgaris
  • Lupus vulgaris of nose
  • Nodular tuberculide
  • Papular tuberculide
  • Scrofuloderma
  • Tuberculid
  • Tuberculoma
  • Tuberculosis cutis indurativa
  • Tuberculosis cutis lichenoides
  • Tuberculosis of skin
  • Tuberculosis of skin and subcutaneous tissue
  • Tuberculosis of subcutaneous cellular tissue
  • Tuberculosis papulonecrotica
  • Tuberculosis verrucosa cutis
  • Tuberculous abscess
  • Tuberculous abscess of neck
  • Tuberculous chancre
  • Tuberculous erythema nodosum
  • Vaccination site lump
  • Vaccination site lump

Clinical Classification

Clinical Information

  • Lupus Vulgaris

    a form of cutaneous tuberculosis. it is seen predominantly in women and typically involves the nasal mucosa; buccal mucosa; and conjunctival mucosa.
  • Tuberculoma

    a tumor-like mass resulting from the enlargement of a tuberculous lesion.
  • Tuberculoma, Intracranial

    a well-circumscribed mass composed of tuberculous granulation tissue that may occur in the cerebral hemispheres, cerebellum, brain stem, or perimeningeal spaces. multiple lesions are quite common. management of intracranial manifestations vary with lesion site. intracranial tuberculomas may be associated with seizures, focal neurologic deficits, and intracranial hypertension. spinal cord tuberculomas may be associated with localized or radicular pain, weakness, sensory loss, and incontinence. tuberculomas may arise as opportunistic infections, but also occur in immunocompetent individuals.
  • Erythema Induratum

    a type of panniculitis characterized histologically by the presence of granulomas, vasculitis, and necrosis. it is traditionally considered to be the tuberculous counterpart of nodular vasculitis, but is now known to occur without tuberculous precedent. it is seen most commonly in adolescent and menopausal women, is initiated or exacerbated by cold weather, and typically presents as one or more recurrent erythrocyanotic nodules or plaques on the calves. the nodules may progress to form indurations, ulcerations, and scars.
  • Tuberculous Abscess

    an abscess resulting from infection by mycobacterium tuberculosis.

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.
  • Erythema induratum, tuberculous
  • Lupus excedens
  • Lupus vulgaris NOS
  • Lupus vulgaris of eyelid
  • Scrofuloderma
  • Tuberculosis of external ear

Type 2 Excludes

Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
  • lupus erythematosus L93
  • systemic lupus erythematosus M32

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).

Convert A18.4 to ICD-9-CM

  • ICD-9-CM Code: 017.00 - TB skin/subcutan-unspec
    Approximate Flag - The approximate mapping means there is not an exact match between the ICD-10 and ICD-9 codes and the mapped code is not a precise representation of the original code.
  • ICD-9-CM Code: 017.10 - Erythema nodos tb-unspec
    Approximate Flag - The approximate mapping means there is not an exact match between the ICD-10 and ICD-9 codes and the mapped code is not a precise representation of the original code.

Patient Education


Skin Infections

What are skin infections?

Your skin is your body's largest organ. It has many different functions, including covering and protecting your body. It helps keep germs out. But sometimes the germs can cause a skin infection. It often happens when the germs enter your body through a break, cut, or wound on your skin. Other skin infections can happen in places where the skin rubs together, especially if the area is moist. Infections can also happen when you have a poor blood supply to an area of your body or if your immune system is weakened because of another disease or a medical treatment.

Some skin infections cover a small area on the top of your skin. Other infections can go deep into your skin or spread to a larger area.

What causes skin infections?

Skin infections are caused by different kinds of germs. For example,:

  • Bacteria cause cellulitis, impetigo, and staphylococcal (staph) infections
  • Viruses cause shingles, warts, and herpes simplex
  • Fungi cause athlete's foot and yeast infections
  • Parasites cause body lice, head lice, and scabies

Who is more likely to get a skin infection?

You are more likely to get a skin infection if you:

  • Have poor circulation
  • Have diabetes
  • Are older
  • Have an immune system disease, such as HIV
  • Have a weakened immune system because of chemotherapy or other medicines that suppress your immune system
  • Have to stay in one position for a long time, such as if you are sick and have to stay in bed for a long time or you are paralyzed
  • Are malnourished
  • Have excessive skinfolds, which can happen if you have obesity

What are the symptoms of skin infections?

The symptoms depend on the type of infection. Some symptoms that are common to many skin infections include rashes, swelling, redness, pain, pus, and itching.

How are skin infections diagnosed?

To diagnose a skin infection, your health care provider will do a physical exam and ask about your symptoms. You may have lab tests, such as a skin culture. This is a test to identify what type of infection you have, using a sample from your skin. Your provider may take the sample by swabbing or scraping your skin or removing a small piece of skin (biopsy). Sometimes providers use other tests, such as blood tests.

How are skin infections treated?

The treatment depends on the type of infection and how serious it is. Some infections will go away on their own. When you do need treatment, it may include a cream or lotion to put on the skin. Other possible treatments include medicines and a procedure to drain pus.


[Learn More in MedlinePlus]

Tuberculosis

What is tuberculosis (TB)?

Tuberculosis (TB) is a bacterial disease that usually attacks the lungs. But it can also attack other parts of the body, including the kidneys, spine, and brain.

Not everyone infected with TB bacteria (germs) becomes sick. So, there are two types of TB conditions:

  • Latent TB infection, where the TB germs live in your body but don't make you sick.
  • TB disease (active TB) where you get sick from the TB germs. TB disease can almost always be cured with antibiotics. But if it's not treated properly, it can be fatal.

TB is found in the U.S., but it is more common in certain other countries.

What causes tuberculosis (TB)?

TB is caused by bacteria (germs) called Mycobacterium tuberculosis. The germs spread from person to person through the air. People who have TB disease in their throat or lungs spread the germs in the air when they cough, sneeze, talk, or sing. If you breathe in the air that has the germs, you can get TB. TB is not spread by touching, kissing, or sharing food or dishes.

You're more likely to catch TB from people you live or work with than from people you see for shorter amounts of time.

Who is more likely to get infected with tuberculosis (TB) germs?

Anyone who is near a person with TB disease can get infected with the germs. You are more likely to be near someone with TB disease if you:

  • Were born in or often travel to countries where TB disease is common
  • Are a health care worker
  • Work or live in a place where TB is more common, such as shelters for people without homes, jails, and nursing homes

Who is more likely to develop TB disease?

Certain people are more likely to get sick with TB disease after they get infected. They include people who:

  • Have HIV
  • Became infected with TB in the last 2 years
  • Have other diseases, such as diabetes, that make it hard for your body to fight TB germs
  • Have alcohol use disorder or inject illegal drugs
  • Were not treated correctly for TB in the past
  • Are under age 5
  • Are an older adult

What are the symptoms of tuberculosis (TB)?

Most people who have TB germs in their bodies don't get sick with TB disease. Instead, they have latent TB infection. With a latent TB infection, you:

  • Don't have symptoms
  • Can't spread TB to others
  • Could get sick with active TB disease in the future if your immune system becomes weak for another reason
  • Need to take medicine to prevent getting sick with active TB disease in the future

If you have TB disease, the TB germs are active, meaning that they are growing (multiplying) inside your body and making you sick. If the TB is growing in your lungs or throat, you can spread the TB germs to other people. You can get sick with TB disease weeks to years after you're infected with TB germs.

With TB disease, your symptoms will depend on where the TB is growing in your body:

  • General symptoms may include:
    • Chills and fever
    • Night sweats (heavy sweating during sleep)
    • Losing weight without trying
    • Loss of appetite
    • Weakness or fatigue
  • Symptoms from TB disease in your lungs may include:
    • A cough that lasts longer than 3 weeks
    • Coughing up blood or sputum (a thick mucus from the lungs)
    • Chest pain

How is tuberculosis (TB) diagnosed?

Your health care provider or your local health department can test you to find out if you have TB germs in your body. They will give you either a TB skin or blood test.

If your test shows that you have TB germs, you'll need to have other tests to see if the germs are actively growing:

  • Tests for TB disease in the lungs usually include testing samples of your sputum and having chest x-rays.
  • Tests for TB disease in other parts of your body may include tests of urine and tissue samples.

You may need a TB test if you have symptoms of TB disease or if you are at high risk because you are more likely to be near someone with TB disease.

What is the treatment for tuberculosis (TB)?

The treatment for both latent TB infection and TB disease is antibiotics. To make sure you get rid of all the TB germs in your body, it's very important to follow the directions for taking your medicine.

If you don't follow the directions, the TB germs in your body could change and become antibiotic resistant. That means the medicine may stop working and your TB may become hard to cure.

  • For latent TB infections, you usually take medicines for 3 to 9 months. Treatment helps make sure you don't get TB disease in the future.
  • For active TB disease, you usually need to take medicines for 6 to 12 months. Treatment will almost always cure you if you take your pills the right way.
  • For TB disease in your lungs or throat, you'll need to stay home for a few weeks, so you don't spread disease to other people. You can protect the people you live with by:
    • Covering your nose and mouth.
    • Opening windows when possible.
    • Not getting too close to them.

By following medical advice for TB testing and treatment, you can keep yourself healthy and help stop the spread of TB.

Centers for Disease Control and Prevention


[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • 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
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.

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.