L51.9 Erythema multiforme, unspecified

Billable ICD-10-CM code, FY2026.

Applicable to

• Erythema iris
• Erythema multiforme major NOS
• Erythema multiforme minor NOS
• Herpes iris

Applies from L51 Erythema multiforme

Excludes1 (never code together)

• staphylococcal scalded skin syndrome (L00)
• Ritter's disease (L00)

Use additional code

• code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)
• code to identify associated manifestations, such as:
• arthropathy associated with dermatological disorders (M14.8-)
• conjunctival edema (H11.42)
• conjunctivitis (H10.22-)
• corneal scars and opacities (H17.-)
• corneal ulcer (H16.0-)
• edema of eyelid (H02.84-)
• inflammation of eyelid (H01.8-)
• keratoconjunctivitis sicca (H16.22-)
• mechanical lagophthalmos (H02.22-)
• stomatitis (K12.-)
• symblepharon (H11.23-)
• code to identify percentage of skin exfoliation (L49.-)

MS-DRG index

Defines the logic of DRG(s) 595-596 in MDC 09.

Approximate ICD-9-CM (GEMs)

• 695.10 Erythema multiforme, unspecified (approximate)

Code annotations containing back-references to L51.9

Back-references to L51

• Code First: M14.8 Arthropathies in other specified diseases classified elsewhere ("erythema multiforme (L51.-)")

Diagnosis Index entries for L51.9

• Arthritis, arthritic (acute) (chronic) (nonpyogenic) (subacute) › in (due to) › erythema › multiforme
• Arthropathy › in (due to) › erythema › multiforme
• Erythema, erythematous (infectional) (inflammation) › iris
• Erythema, erythematous (infectional) (inflammation) › multiforme (major) (minor)
• Herpes, herpesvirus, herpetic › iris (vesicular erythema multiforme)

Nearby codes

• L51.0 Nonbullous erythema multiforme
• L51.1 Stevens-Johnson syndrome
• L51.2 Toxic epidermal necrolysis [Lyell]
• L51.3 Stevens-Johnson syndrome-toxic epidermal necrolysis overlap syndrome
• L51.8 Other erythema multiforme
• L51.9 Erythema multiforme, unspecified (this code)