L27Dermatitis due to substances taken internally

L27 is the ICD-10-CM diagnosis code for dermatitis due to substances taken internally. It belongs to block L20-L30 (dermatitis and eczema) and chapter 12 (diseases of the skin and subcutaneous tissue). It is a header code, so it can't be reported by itself; one of its 5 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: L27.0 (internally), L27.1 (internally), L27.2 (food), L27.8 (internally) and L27.9 (internally).

Don't report L27 together with the conditions in its Excludes1 note: allergy NOS (T78.40).

The conditions in its Excludes2 note aren't part of L27, but may be coded alongside it if the patient has both: adverse food reaction, except dermatitis (T78.0-T78.1), contact dermatitis (L23-L25), drug photoallergic response (L56.1), drug phototoxic response (L56.0) and 1 more.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.