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? Answer:
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 digit 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).