Dermatology Coding Alert

You Be the Coder:

Skin Rash With Unknown Cause

Question: We recently treated a patient for a skin rash that seemed to be an allergic reaction to some unknown cause. Which diagnosis code should we use?

Virginia Subscriber

Answer:  There are several possibilities for coding the unknown skin rash. More information from the physician will help to identify the best choice. When deciding the most appropriate code, consider 782.1 (Rash and other nonspecific skin eruption) with 782.0 (Disturbance of skin sensation) to indicate itching or burning.

If the rash is further identified, you may consider selections from category 692.x (Contact dermatitis and other eczema). This category includes "Dermatitis: Not Otherwise Specified (NOS), contact, occupational, venenata"; and "Eczema (acute or chronic): NOS, allergic, erythematous, occupational."

You must also use a fourth or fifth character with this category, which excludes certain types of dermatitis.

You may also consider these codes: allergy NOS (995.3), contact dermatitis of eyelids (373.32), dermatitis due to substances taken internally (693.0-693.9), eczema of external ear (380.22), perioral dermatitis (695.3), or urticarial reactions (708.0-708.9, 995.1).