L04
Acute lymphadenitis
L04 is a non-billable ICD-10-CM code category for acute lymphadenitis. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are L04.0 Acute lymphadenitis of face, head and neck; L04.1 Acute lymphadenitis of trunk; L04.2 Acute lymphadenitis of upper limb; L04.3 Acute lymphadenitis of lower limb and 2 more. Its coding notes include a Use additional code instruction, 5 Excludes1 entries and 23 Excludes2 entries.
Use additional code
Add the listed code as a secondary code, if known.
Excludes1
Not coded here. The listed conditions generally should not be reported together.
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (23 notes)
- hordeolum (H00.0)
- infective dermatitis (L30.3)
- local infections of skin classified in Chapter 1
- lupus panniculitis (L93.2)
- panniculitis NOS (M79.3)
- panniculitis of neck and back (M54.0-)
- Perlèche NOS (K13.0)
- Perlèche due to candidiasis (B37.0)
- Perlèche due to riboflavin deficiency (E53.0)
- pyogenic granuloma (L98.0)
- relapsing panniculitis [Weber-Christian] (M35.6)
- viral warts (B07.-)
- zoster (B02.-)
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- lipomelanotic reticulosis (I89.8)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
- systemic connective tissue disorders (M30-M36)
- viral warts (B07.-)
Includes
Further defines or gives examples of the content of the category.
- abscess (acute) of lymph nodes, except mesenteric
- acute lymphadenitis, except mesenteric