T78.40 Allergy, unspecified
Non-billable ICD-10-CM code.
Applicable to
- Allergic reaction NOS
- Hypersensitivity NOS
Applies from T78 Adverse effects, not elsewhere classified
Excludes2 (not included here)
- complications of surgical and medical care NEC (T80-T88)
7th character note
- The appropriate 7th character is to be added to each code from category T78
7th character required
- A — initial encounter
- D — subsequent encounter
- S — sequela
Applies from T78.4 Other and unspecified allergy
Excludes1 (never code together)
- specified types of allergic reaction such as:
- allergic diarrhea (K52.29)
- allergic gastroenteritis and colitis (K52.29)
- dermatitis (L23-L25, L27.-)
- food protein-induced enterocolitis syndrome (K52.21)
- food protein-induced enteropathy (K52.22)
- hay fever (J30.1)
Code annotations containing back-references to T78.40
Back-references to T78.40
- Type 1 Excludes:
L23 Allergic contact dermatitis ("allergy NOS (T78.40)") - Type 1 Excludes:
L24 Irritant contact dermatitis ("allergy NOS (T78.40)") - Type 1 Excludes:
L25 Unspecified contact dermatitis ("allergy NOS (T78.40)") - Type 1 Excludes:
L27 Dermatitis due to substances taken internally ("allergy NOS (T78.40)")
Back-references to T78
- Type 1 Excludes:
T75 Other and unspecified effects of other external causes ("adverse effects NEC (T78.-)")
Diagnosis Index entries for T78.40
- Allergy, allergic (reaction) (to)
- Allergy, allergic (reaction) (to) › drug, medicament & biological (any) (external) (internal)
- Hypersensitive, hypersensitiveness, hypersensitivity › reaction
Nearby codes
T78.3 Angioneurotic edemaT78.3XXA Angioneurotic edema, initial encounterT78.3XXD Angioneurotic edema, subsequent encounterT78.3XXS Angioneurotic edema, sequelaT78.4 Other and unspecified allergyT78.40 Allergy, unspecified (this code)T78.40XA Allergy, unspecified, initial encounterT78.40XD Allergy, unspecified, subsequent encounterT78.40XS Allergy, unspecified, sequelaT78.41 Arthus phenomenonT78.41XA Arthus phenomenon, initial encounter