American Society of Hirudotherapy

Cutaneous complications of improper leech application

Research article published in Annals of agricultural and environmental medicine : AAEM (2012)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Case reportClinical TrialsSafety & Infection ControlPietrzak A et al. · Annals of agricultural and environmental medicine : AAEM, 2012

Abstract

INTRODUCTION: The medical leech (Hirudo medicinalis) has been used throughout the centuries and continues to be used today, mainly in reconstructive surgery and microsurgery. Easy access to these animals may entail an improper use of this therapeutic method by patients as a form of self-treatment. CASE REPORT: A man who presented with skin erythema and oedema due to the application of a medical leech. DISCUSSION: Infection is considered the most common complication of hirudotherapy, even though bacteriological examination of leech applied by the patient showed neither bacterial nor parasitic infection. The skin lesions were probably of allergic origin; whether this reaction was due to substances released from the leech or as a consequence of reusing the same leech, remains to be determined.

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

Publication typeCase ReportsJournal Article
Indexed MeSH termsAnimalsCryotherapyDermatitis, ContactDiagnosis, DifferentialHirudo medicinalisHumansLeechingMaleMiddle AgedPolandTreatment Outcome

Summary

The medical leech (Hirudo medicinalis) has been used throughout the centuries and continues to be used today, mainly in reconstructive surgery and microsurgery.

Why This Matters for Hirudotherapy

This case report documents a man who presented with skin erythema and oedema following self-application of a medical leech (Hirudo medicinalis). Bacteriological examination of the leech showed no bacterial or parasitic infection, and the authors suggest the skin lesions were probably of allergic origin, possibly due to substances released from the leech or to reuse of the same leech. The report is directly relevant to hirudotherapy safety, as it highlights potential cutaneous adverse reactions and the risks of unsupervised self-treatment with medicinal leeches. However, as a single case report involving patient self-administered rather than clinically supervised leech therapy, with the precise cause of the reaction remaining undetermined, its findings offer limited insight into the incidence or mechanisms of allergic complications during proper hirudotherapy.

Citation

Cutaneous complications of improper leech application.

Pietrzak A et al. · Annals of agricultural and environmental medicine : AAEM, 2012

DOI

Added to ASH library: March 18, 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.