T78.41

Arthus phenomenon

Not billable — category only FY2026 2025-10-01 → 2026-09-30

Exclusions 10 never code together

T78code

Excludes2

Excludes1

specified types of allergic reaction such as:
allergic diarrhea (K52.29)K52.29
allergic gastroenteritis and colitis (K52.29)K52.29
dermatitis (L23-L25, L27.-)L23-L25 L27.-
food protein-induced enterocolitis syndrome (K52.21)K52.21
food protein-induced enteropathy (K52.22)K52.22
hay fever (J30.1)J30.1

Excludes2

Excludes1 — never code together. The excluded condition and this one are mutually exclusive.

Excludes2 — not included here, but the patient may have both. Code both when documented.

7th character 3

A initial encounter

D subsequent encounter

S sequela

Instructional notes 4

Inclusion terms

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
The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.

Use additional code

Index entries leading here 1

Alongside this code 2 same parent — T78.4

Additional references

AHA Coding Clinic® Licence required

Official coding advice for this code. Published by the American Hospital Association. Not included in this installation.

Maps to no condition category in any loaded model.

Presence is a property of the code. Untick a model to hide it everywhere.

Present FY2024–FY2027.