ICD10BillableValid for clinical use

ICD-10 Code T78.41: Arthus phenomenon

T78.41 is a billable ICD-10 diagnosis code used to classify Arthus phenomenon in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Injury, poisoning and certain other consequences of external causes (S00-T88).

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Injury, poisoning and certain other consequences of external causes (S00-T88).

When is it used?

  • May be used when a clinician documents arthus phenomenon in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.

Code hierarchy

chapter
19Injury, poisoning and certain other consequences of external causes (S00-T88)
block
T07-T88Injury, poisoning and certain other consequences of external causes
block
T66-T78Other and unspecified effects of external causes
category
T78Adverse effects, not elsewhere classified
category
T78.4Other and unspecified allergy
currentT78.4

Official coding notes

Inclusion terms
  • Arthus reaction

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Related specialists

Emergency Medicine SpecialistOrthopedic Specialist

Coding guidelines

Common synonyms

Arthus phenomenon

Frequently asked questions

Code details

CodeT78.41
SystemICD10
Display nameArthus phenomenon
ChapterInjury, poisoning and certain other consequences of external causes (S00-T88)
BlockOther and unspecified effects of external causes

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
Arthus' phenomenon or reaction

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

ICD-10 Code T78.41 for Arthus phenomenon | HealthAssure