ICD-10-CM Code for Poison Ivy Rash
The appropriate ICD-10-CM code for allergic contact dermatitis due to poison ivy affecting the bilateral arms, face, right shoulder, and upper back is L23.7 (Allergic contact dermatitis due to plants, except food).
Understanding the Coding
The ICD-10-CM classification system uses L23.7 specifically for allergic contact dermatitis caused by plants, which includes poison ivy, poison oak, and poison sumac (Toxicodendron species). This single code captures the diagnosis regardless of the number of body sites affected 1.
Key Coding Principles
Single code application: You do not need separate codes for each anatomical location (bilateral arms, face, right shoulder, upper back). The L23.7 code encompasses all affected areas in a single diagnosis.
Laterality is not specified: Unlike some ICD-10 codes that require laterality modifiers, contact dermatitis codes do not distinguish between unilateral, bilateral, right, or left involvement.
Plant-specific classification: The code L23.7 is designated specifically for plant-related allergic contact dermatitis, distinguishing it from other forms of contact dermatitis (irritant, chemical, etc.).
Clinical Context
Contact dermatitis from Toxicodendron species (poison ivy, oak, sumac) affects millions of Americans annually, with approximately 50-75% of individuals reacting to urushiol, the allergenic compound 1. The condition presents with erythema, papules, vesicles, and itching, typically starting within days of exposure and lasting up to 3 weeks.
Documentation Tips
When documenting for coding purposes, ensure your clinical notes clearly indicate:
- The causative agent (poison ivy)
- The allergic nature of the reaction (not irritant)
- All affected body sites for clinical completeness (even though a single code applies)
- Timing and severity of symptoms
Important caveat: If the patient has secondary complications such as infection or if you're treating with systemic corticosteroids, additional codes may be needed for those specific interventions or complications, but the primary diagnosis remains L23.7.