2024 ICD-10-CM Diagnosis Code A18.4

by

Tuberculosis of skin and subcutaneous tissue

  • A18.4 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
  • The 2024 edition of ICD-10-CM A18.4 became effective on October 1, 2023.
  • This is the American ICD-10-CM version of A18.4 – other international versions of ICD-10 A18.4 may differ.

Applicable To

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

Type 2 Excludes

  • lupus erythematosus (L93.-)
  • systemic lupus erythematosus (M32.-)

The following code(s) above A18.4 contain annotation back-references

 that may be applicable to A18.4:

  • A00-B99  Certain infectious and parasitic diseases
  • A15-A19  Tuberculosis

Approximate Synonyms

  • Tuberculosis (tb) of subcutaneous tissue
  • Tuberculosis (tb) verrucosa cutis
  • Tuberculosis (tb) with erythema nodosum
  • Tuberculosis of subcutaneous cellular tissue
  • Tuberculosis verrucosa cutis
  • Tuberculous erythema nodosum

Clinical Information

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

ICD-10-CM A18.4 is grouped within Diagnostic Related Group(s) (MS-DRG v41.0):

  • 606 Minor skin disorders with mcc
  • 607 Minor skin disorders without mcc
  • 974 Hiv with major related condition with mcc
  • 975 Hiv with major related condition with cc
  • 976 Hiv with major related condition without cc/mcc

Convert A18.4 to ICD-9-CMCode History

  • 2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
  • 2017 (effective 10/1/2016): No change
  • 2018 (effective 10/1/2017): No change
  • 2019 (effective 10/1/2018): No change
  • 2020 (effective 10/1/2019): No change
  • 2021 (effective 10/1/2020): No change
  • 2022 (effective 10/1/2021): No change
  • 2023 (effective 10/1/2022): No change
  • 2024 (effective 10/1/2023): No change

Code annotations containing back-references to A18.4:

Diagnosis Index entries containing back-references to A18.4:

  • Acnitis A18.4 (primary)
  • Bazin’s disease A18.4 (primary) (tuberculous)
  • Cellulitis (diffuse) (phlegmonous) (septic) (suppurative) L03.90
    • tuberculous A18.4 (primary)
  • Erythema, erythematous (infectional) (inflammation) L53.9
    • induratum (nontuberculous) L52
      • tuberculous A18.4
    • nodosumL52
      • tuberculous A18.4
    • tuberculous A18.4 (primary)
  • Gumma (syphilitic) A52.79
    • scrofulous A18.4 (tuberculous)
    • tuberculous A18.4
  • LichenL28.0
    • scrofulosus A18.4 (primary) (tuberculous)
  • Lichenoides tuberculosis A18.4 (primary)
  • Lupus
  • Paronychia – see also Cellulitis, digit
    • tuberculous A18.4 (primary)
  • Scrofulide A18.4 (primary) (tuberculous)
  • Scrofuloderma, scrofulodermia A18.4 (any site) (primary)
  • Scrofulosus lichen A18.4 (primary) (tuberculous)
  • Tarsitis (eyelid) H01.8
    • tuberculous A18.4
  • Tuberculid, tuberculide A18.4 (indurating, subcutaneous) (lichenoid) (miliary) (papulonecrotic) (primary) (skin)
  • Tuberculosis, tubercular, tuberculous (calcification) (calcified) (caseous) (chromogenic acid-fast bacilli) (degeneration) (fibrocaseous) (fistula) (interstitial) (isolated circumscribed lesions) (necrosis) (parenchymatous) (ulcerative) A15.9
    • abscess (respiratory) A15.9
      • skin A18.4 (primary)
    • ear (inner) (middle) A18.6
      • external A18.4 (primary)
      • skin A18.4 (primary)
    • ulcer (skin) (primary) A18.4
    • cellulitis A18.4 (primary)
    • colliquativa A18.4 (primary)
    • cutis A18.4 (colliquativa) (primary)
    • erythema A18.4 (induratum) (nodosum) (primary)
    • eyelid A18.4 (primary) (lupus)
    • indurativa A18.4 (primary)
    • lichenoides A18.4 (primary)
    • lupus vulgaris A18.4
    • papulonecrotic A18.4 (a) (primary)
    • paronychia A18.4 (primary)
    • skin A18.4 (any site) (primary)
    • subcutaneous tissue A18.4 (cellular) (primary)
    • subcutis A18.4 (primary)
    • tarsitis A18.4
    • verruca, verrucosa A18.4 (cutis) (primary)
  • Ulcer, ulcerated, ulcerating, ulceration, ulcerative
    • skin (atrophic) (chronic) (neurogenic) (non-healing) (perforating) (pyogenic) (trophic) (tropical) L98.499
      • tuberculous A18.4 (primary)
  • Ulcus – see also Ulcer
    • cutis tuberculosum A18.4
  • Verruca (due to HPV) (filiformis) (simplex) (viral) (vulgaris) B07.9
    • necrogenica A18.4 (primary) (tuberculosa)
    • tuberculosa A18.4 (primary)
  • Wart (due to HPV) (filiform) (infectious) (viral) B07.9
    • prosector A18.4 (tuberculous)
    • tuberculous A18.4