American Society of Hirudotherapy

An unusual cause of unilateral epistaxis: a leech in the nose

Case report published in Revista do Instituto de Medicina Tropical de Sao Paulo (2025)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Case reportClinical TrialsYasar M · Revista do Instituto de Medicina Tropical de Sao Paulo, 2025

Abstract

Leeches are segmental worms commonly found in fresh water in tropical regions. They can enter the human body via the consumption of contaminated water or through the mouth and nose during washing, generally affecting the upper airway and digestive tract. During the blood-sucking process, the leech releases the anticoagulant enzyme "hirudin" from the wound site into the host's circulation together with an anesthetic to prevent the host from feeling its attachment. Leech endoparasitism is a very rare cause of epistaxis. We report a case of a living leech lodged in the posterior nasal floor in a patient that presented to the emergency department with unilateral epistaxis and a difficult diagnosis.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeCase ReportsJournal Article
Indexed MeSH termsAnimalsHumansEpistaxisForeign BodiesLeechesNoseParasitic Diseases

Summary

Leeches are segmental worms commonly found in fresh water in tropical regions.

Why This Matters for Hirudotherapy

This case report details a patient who presented with unilateral epistaxis caused by a living leech lodged in the posterior nasal floor. The abstract specifically notes the leech's blood-sucking mechanism, highlighting the release of the anticoagulant enzyme "hirudin" and an anesthetic to prevent the host from feeling the attachment. For the American Society of Hirudotherapy, this illustrates the in vivo pharmacological action of leech secretions, particularly hirudin's anticoagulant effects causing prolonged bleeding. The limitation is that this is an isolated case of accidental leech endoparasitism rather than a clinical trial of therapeutic hirudotherapy, thus offering indirect clinical pharmacological observations rather than therapeutic efficacy data.

Citation

An unusual cause of unilateral epistaxis: a leech in the nose

Yasar M · Revista do Instituto de Medicina Tropical de Sao Paulo, 2025

Added to ASH library: May 27, 2026 · Site last updated: June 18, 2026

This website provides educational information and does not constitute medical advice, diagnosis, or treatment recommendations. Medicinal leech therapy carries clinically meaningful risks and should be performed only by qualified clinicians under institutionally approved protocols. FDA 510(k) clearance for medicinal leeches is limited to specific indications; investigational and off-label discussions are labeled accordingly. For patient-specific guidance, consult a qualified healthcare provider.