T78.40XD Allergy, unspecified, subsequent encounter

Instructional Notes:

T78.40XD
Description: Allergy, unspecified, subsequent encounter
↓
T78.40
Description: Allergy, unspecified
Inclusion Term:
- Allergic reaction NOS
- Hypersensitivity NOS
↓
T78.4
Description: Other and unspecified allergy
Exclude1:
- 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)
↓
T78
Description: Adverse effects, not elsewhere classified
Exclude2:
- complications of surgical and medical care NEC (T80-T88)
↓
T66-T78
Description: Other and unspecified effects of external causes (T66-T78)
↓
S00-T88
Description: Injury, poisoning and certain other consequences of external causes
Exclude2:
- birth trauma (P10-P15)
- obstetric trauma (O70-O71)
Notes:
- Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
Use Additional Code:
- code to identify any retained foreign body, if applicable (Z18.-)