2026 ICD-10-CM Diagnosis Code I73.81Erythromelalgia

ICD-10-CM Codes›I00–I99›I70-I79›I73

ICD-10-CM I73.81
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I73.81 is a billable ICD-10-CM diagnosis code for erythromelalgia. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 299 through 301. Coders also document this condition as drug-induced erythromelalgia. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Peripheral and visceral vascular disease.

Code Identity

ICD-10-CM Code
I73.81
Billable Status
Yes — Valid for Submission
Code Describes
Erythromelalgia
Short Description
Erythromelalgia
Same as the full description in the CMS dataset.
Parent Code
I73.8
Other specified peripheral vascular diseases

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI70-I79Diseases of arteries, arterioles and capillaries
CategoryI73Other peripheral vascular diseases
This CodeI73.81Erythromelalgia

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Drug-induced erythromelalgia
  • Erythromelalgia
  • Primary erythromelalgia
  • Secondary erythromelalgia
  • Vasodilatation disorder of extremities

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Acromelalgia
    • Disease, diseased
      • Gerhardt's (erythromelalgia)
    • Disease, diseased
      • Mitchell's (erythromelalgia)
    • Disease, diseased
      • Weir Mitchell's (erythromelalgia)
    • Erythermalgia(primary)
    • Erythralgia
    • Erythromelalgia
    • Gerhardt's
      • disease (erythromelalgia)
    • Mitchell's disease(erythromelalgia)
    • Weir Mitchell's disease

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR CIR026
Peripheral and visceral vascular disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Erythromelalgia

    a peripheral arterial disease that is characterized by the triad of erythema, burning pain, and increased skin temperature of the extremities (or red, painful extremities). erythromelalgia may be classified as primary or idiopathic, familial or non-familial. secondary erythromelalgia is associated with other diseases, the most common being myeloproliferative disorders.

  • Erythromelalgia

    a rare disorder characterized by periodic inflammation and blockage of the vessels of the extremities, resulting in skin redness, swelling, and burning pain in the affected sites. it may manifest as a primary disorder caused by mutations of the scn9a gene or as a secondary disorder due to hematologic disorders or medication side effects.

  • Primary Erythermalgia|PERYTHM|Primary Erythromelalgia

    an autosomal dominant condition caused by mutation(s) in the scn9a gene, encoding sodium channel protein type 9 subunit alpha. it is characterized by episodes of recurrent warmth, redness, and burning sensations in the extremities.

  • Primary Erythromelalgia|PERYTHM|Primary Erythermalgia

    an autosomal dominant condition caused by mutation(s) in the scn9a gene, encoding sodium channel protein type 9 subunit alpha. it is characterized by episodes of recurrent warmth, redness, and burning sensations in the extremities.

Patient EducationClinical

Erythromelalgia

Erythromelalgia is a condition characterized by episodes of pain, redness, and swelling in various parts of the body, particularly the hands and feet. These episodes are usually triggered by increased body temperature, which may be caused by exercise or entering a warm room. Ingesting alcohol or spicy foods may also trigger an episode.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert I73.81 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
443.82 Erythromelalgia
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About I73.81Overview

Is I73.81 (Other specified peripheral vascular diseases) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report erythromelalgia on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does I73.81 group to?

When erythromelalgia is the principal diagnosis on an inpatient stay, it groups to MS-DRG 299, 300, 301, with relative weights from 0.7197 to 1.6327 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of I73.81?

Under the General Equivalence Mappings, erythromelalgia converts to ICD-9-CM 443.82 (erythromelalgia). The mapping is a direct match.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.