L03.31A Cellulitis of flank

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applies from L03 Cellulitis and acute lymphangitis

Excludes2 (not included here)

• cellulitis of anal and rectal region (K61.-)
• cellulitis of external auditory canal (H60.1)
• cellulitis of eyelid (H00.0)
• cellulitis of female external genital organs (N76.4)
• cellulitis of lacrimal apparatus (H04.3)
• cellulitis of male external genital organs (N48.2, N49.-)
• cellulitis of mouth (K12.2)
• cellulitis of nose (J34.0)
• eosinophilic cellulitis [Wells] (L98.3)
• febrile neutrophilic dermatosis [Sweet] (L98.2)
• lymphangitis (chronic) (subacute) (I89.1)

Applies from L03.31 Cellulitis of trunk

Excludes2 (not included here)

• cellulitis of anal and rectal regions (K61.-)
• cellulitis of breast NOS (N61.0)
• cellulitis of female external genital organs (N76.4)
• cellulitis of male external genital organs (N48.2, N49.-)
• omphalitis of newborn (P38.-)
• puerperal cellulitis of breast (O91.2)

MS-DRG index

Defines the logic of DRG(s) 573-575 in MDC 09.

Code annotations containing back-references to L03.31A

Back-references to L03

• Type 1 Excludes: I89.1 Lymphangitis ("acute lymphangitis (L03.-)")
• Type 2 Excludes: L89 Pressure ulcer ("skin infections (L00-L08)")
• Type 2 Excludes: L97 Non-pressure chronic ulcer of lower limb, not elsewhere classified ("skin infections (L00-L08)")
• Type 2 Excludes: L98.4 Non-pressure chronic ulcer of skin, not elsewhere classified ("skin infections (L00-L08)")
• Type 2 Excludes: L98.A Non-pressure chronic ulcer of upper limb, not elsewhere classified ("skin infections (L00-L08)")
• Use Additional: T65.84 Toxic effect of xylazine ("cellulitis and acute lymphangitis (L03.-)")

Diagnosis Index entries for L03.31A

• Cellulitis (diffuse) (phlegmonous) (septic) (suppurative) › flank

Nearby codes

• L03.314 Cellulitis of groin
• L03.315 Cellulitis of perineum
• L03.316 Cellulitis of umbilicus
• L03.317 Cellulitis of buttock
• L03.319 Cellulitis of trunk, unspecified
• L03.31A Cellulitis of flank (this code)
• L03.32 Acute lymphangitis of trunk
• L03.321 Acute lymphangitis of abdominal wall
• L03.322 Acute lymphangitis of back [any part except buttock]
• L03.323 Acute lymphangitis of chest wall
• L03.324 Acute lymphangitis of groin