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ORPHA:90026

Primary erythromelalgia

high confidenceDisorder

Also known as: Primary erythermalgia

Publications

399

78.1th percentile

Trials

2

Interventional, condition-specific

Researchers

1,026

Distinct authors in sample

Gene link

SCN9A

Definitive

Readiness

3/6

Stages with a signal

Clinical definition (Orphanet)

Primary erythermalgia is characterized by intermittent attacks of red, warm, painful burning extremities. It spontaneously arises during early childhood and adolescence in the absence of any detectable underlying disorder.

How rare: How common this is has not been clearly measured.

Orphanet entry

Cross-references

Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.

Additional Mondo synonyms (2)

PERYTHM · primary erythromelalgia

Research stages

Trial readiness signals

Where this condition sits on an open-data research pipeline — not how close a treatment is, and not medical advice. Empty stages often mean “not in these databases under this Mondo ID,” not “impossible.”

3/6 stages with a signal

An interventional trial matched this condition name on ClinicalTrials.gov — see trials below.

  1. Gene identifiedPresent

    Definitive — SCN9A

  2. LiteraturePresent

    399 matched papers (192 in last 10 years) Source

  3. Phenotype characterisedNot checked

    Not yet enriched from Monarch / HPO

  4. Animal modelNot checked

    Not yet enriched from Monarch / Alliance

  5. Orphan designationNot checked

    FDA/EMA orphan-drug designation not enriched yet

  6. Interventional trialPresent

    2 matched on ClinicalTrials.gov

Biology

Genes and phenotypes

Gene–disease validity from GenCC, plus phenotypes and animal models joined from Monarch Initiative via Mondo ID — not a clinical diagnosis aid.

Do we know what causes it?

Yes — we know a specific gene responsible (SCN9A).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

Not enriched in this build — Monarch phenotype joins were not run for this record.

Animal models (Monarch / Alliance)

Not enriched in this build.

Literature

Is anyone studying this?

399

399 papers have ever been published on this condition (under this name). For scale, breast cancer has over 700,000. Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=5449) is 41.

399 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 41 (publications denominator n=5449).

192 in the last 10 years · high confidence · 78.1th percentile (publications denominator)

Phrase hits: 399 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,026

Distinct author names in 200 sampled papers — named people below.

Who's working on it?

People publishing on this condition (sampled Europe PMC records). Affiliation is the most recent found in that sample.

  1. 01
    Drenth JP7 papers · 2008

    Department of Medicine, Division of Gastroenterology and Hepatology, University Medical Center St. Radboud, Nijmegen, The Netherlands. JoostPHDrenth@CS.com

    Papers in Europe PMC
  2. 02
    Li J6 papers · 2026

    Beijing Frontier Research Center for Biological Structures, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China.

    Papers in Europe PMC
  3. 03
    Cox JJ5 papers · 2026

    Wolfson Institute for Biomedical Research, Division of Medicine, University College London, Gower Street, London, WC1E 6BT, UK. j.j.cox@ucl.ac.uk.

    Papers in Europe PMC
  4. 04
    Te Morsche RH5 papers · 2008
    Papers in Europe PMC
  5. 05
    Wood JN5 papers · 2024

    Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, UK.

    Papers in Europe PMC
  6. 06
    Kurth I4 papers · 2023

    Institute of Human Genetics, Jena University Hospital, 07743 Jena, Germany.

    Papers in Europe PMC
  7. 07
    Waxman SG4 papers · 2018
    Papers in Europe PMC
  8. 08
    Yang Y4 papers · 2009

    Department of Dermatology, Peking University First Hospital, Beijing, China.

    Papers in Europe PMC
  9. 09
    Bertelli M3 papers · 2020

    MAGI'S LAB, Rovereto (TN), Italy; MAGI EUREGIO, Bolzano, Italy; EBTNA-LAB, Rovereto (TN), Italy. matteo.bertelli@assomagi.org.

    Papers in Europe PMC
  10. 10
    Cregg R3 papers · 2014

    Molecular Nociception Group, Wolfson Institute for Biomedical Research, UCL, Gower Street, London WC1E 6BT, UK.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

2

interventional trials for this specific condition

2 interventional trials matched this specific condition name; none in our sample are currently recruiting. 6 trials are registered for erythromelalgia, the broader category — shown separately because they may or may not enrol this specific subtype.

Data as of 27 July 2026

2 interventional trials — more than 73% of diseases in the trials denominator have none at all (5114 of 7003; this disease is at the 82.4th percentile).

high confidence · 82.4th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

2 interventional trials matched after quoted-phrase search and title/condition post-filter.

No currently recruiting studies in the matched set. Open the same search on ClinicalTrials.gov.

Broader category: erythromelalgia

6

Interventional trials for the parent category, exclusive of NCT IDs already counted above. Eligibility for this subtype is not guaranteed.

Worth raising with a clinician. How we count trials.

Recruiting under the broader category

Observational and natural-history studies

3 observational studies match this condition. These do not test a treatment and are not counted in the interventional-trial headline, but they are genuine research: natural-history work often defines the endpoints needed for a future rare-disease trial, and families may be able to enroll.

Recruiting or not-yet-recruiting

Open the complete matched search on ClinicalTrials.gov

Where to find support

We do not yet link condition-specific patient organisations. These umbrella groups support undiagnosed and ultra-rare families:

India — NPRD

Last verified 2026-07-26

This ORPHAcode is not on our curated NPRD list (direct or Mondo-parent match). That does not decide clinical eligibility; families in India should ask a notified Centre of Excellence about current coverage.

Hand-curated for this project. ORPHAcode mappings are best-effort and may be incomplete or imprecise for umbrella categories. Parent (Mondo) matches mean the policy lists a broader category — confirm eligibility with a Centre of Excellence. Financial entitlements summarised from public policy statements and may change. This is not official government guidance.

How we counted this

Europe PMC query (preferred label + any corrected label + Orphanet and Mondo exact synonyms, stoplisted; unioned with resolved MeSH labels when available). UMLS / OMIM / NCIT cross-references are stored on the overview but are not added to the query string.

"Primary erythromelalgia" OR "Primary erythermalgia" OR "PERYTHM"

Run this search on Europe PMC

ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):

"Primary erythromelalgia" OR "Primary erythermalgia" OR "PERYTHM" OR "SCN9A"

Recall-expansion terms: SCN9A

Interventional trials matched via: phrase (mesh = registered under a MeSH descriptor no name phrase would catch; recall-expansion = gene / selected parent terms used only for trials).

Study-type breakdown: 2 interventional · 3 observational · 0 expanded access. Only interventional studies enter the trial headline.

Parent-category trials query:

"erythromelalgia"

Query health: ok — strategies attempted: phrase, recall-expansion; with hits: phrase, recall-expansion

Run this search on ClinicalTrials.gov

Confidence reasoning

  • Preferred label is multi-word and distinctive
  • No synonyms dropped by stoplist
  • No label/synonym collisions with other diseases in this corpus

Ingested 2026-07-27T03:30:00.295Z