Amerikanische Gesellschaft für Hirudotherapie

Thumb Carpometacarpal (CMC-1) Osteoarthritis

Off-label use with RCT evidence: single-session leech therapy reduces pain and improves function in CMC-1 (basal thumb) OA at 8 weeks.

Tier B — RCT-supported off-labelOff-Label untersuchtLast updated: 2026-05-26 · Reviewed by ASH Editorial Board

Patienten-Zusammenfassung

Ist dies FDA-zugelassen fuer diese Anwendung?
No — investigated off-label. The FDA cleared medicinal leeches in 2004 only for venous congestion in microsurgical reconstruction (K040187). Use for thumb base osteoarthritis is supported by published research but not FDA-evaluated.
Welche Evidenz existiert?
One small randomized trial (Michalsen 2008, n=32) and a follow-up observational series (Bachmann 2017, n=30) found single-session leech therapy reduced thumb pain and improved hand function compared to NSAID gel, with effects measured at 4 to 8 weeks and durability reported through 6 months in the observational data. Evidence comes from a single research group, the sample sizes are small, and there are no large multi-center confirmation trials. This is not a replacement for hand therapy, splinting, or surgical options when those are appropriate.
Hauptrisiken
  • Bleeding and oozing from each bite site for several hours after the leech detaches
  • Itching, redness, and irritation at the bite sites for days to weeks
  • Local skin infection or, rarely, Aeromonas infection from leech gut bacteria
  • Allergic reaction to leech saliva (uncommon)
  • Small permanent scars at the bite sites
  • Temporary increase in pain during the bite (most patients describe it as a brief, sharp sting)
Wer dies nicht in Betracht ziehen sollte
  • Patients taking blood thinners such as warfarin, apixaban, rivaroxaban, dabigatran, or heparin
  • Patients with hemophilia or other inherited bleeding disorders
  • Patients with severe anemia (hemoglobin under 10 g/dL)
  • Patients with a weakened immune system, especially severe neutropenia
  • Patients with an active skin or joint infection at or near the thumb
  • Pregnant patients (relative caution, especially first and third trimester)
Was Sie Ihren Kliniker fragen sollten
  • Have I tried splinting, hand therapy, and standard pain medications first?
  • What does my hand surgeon think — am I a candidate for steroid injection or surgery soon?
  • What is the realistic chance leech therapy will help my thumb, and for how long?
  • Has the practitioner treated thumb arthritis with leeches before, and what supplier do they use?
  • What antibiotic prevention plan do you use for Aeromonas?
  • What is the cost, and is any of it covered by insurance? (typically not, since it is off-label)
  • What is the plan if symptoms return — repeat session, injection, or surgical referral?
Wann dringende medizinische Versorgung suchen
  • Bleeding from a bite site lasting more than 24 hours
  • Spreading redness, warmth, pus, or red streaks around the bite sites
  • Fever above 38.0 C / 100.4 F or chills
  • Sudden severe thumb or wrist pain, swelling, or inability to move the joint
  • Hives, facial swelling, throat tightness, or breathing difficulty

Was dies NICHT bedeutet

  • It does not mean leech therapy is FDA-approved for thumb arthritis — it is not.
  • It does not mean leeches cure the underlying cartilage wear — they may temporarily reduce pain.
  • It does not mean leech therapy is better than splinting, hand therapy, steroid injection, or surgery — those have stronger evidence and remain standard care.
  • It does not mean every patient benefits — published trials show meaningful improvement on average, but individual results vary.

Clinical Profile

Category
musculoskeletal
ICD-10
M18.0, M18.10, M18.11, M18.12
Safety tier
low

Evidence Summary

A single randomized controlled trial (2008, n=32 women with symptomatic first-carpometacarpal-joint osteoarthritis) compared a single session of local leech therapy (2-3 leeches) to a 30-day course of topical diclofenac. Overall pain (mean VAS at rest, in motion, and during grip) at day 7 fell from 59.6 to 27.1 in the leech group versus 50.6 to 46.9 with diclofenac, a group difference of -26.5 (95% CI -40.3 to -12.7; p=0.0003), and the pain advantage favoring leech therapy increased further at days 30 and 60. Function (DASH), quality of life, and grip strength also improved, with benefit persisting for at least two months. The basal thumb joint is a favorable target because it is superficial and small leech doses suffice. Evidence rests on this single trial; larger and longer-term confirmatory studies are lacking, so use remains investigational.

Treatment specifics

How many leeches, where they are placed, how long a session lasts, and whether to repeat are clinical decisions made by a qualified provider under institutional protocol — not something to self-administer. Discuss the specifics with a clinician experienced in medicinal leech therapy. (Clinicians: switch the audience selector in the top bar to “Clinician” to view protocol detail.)

Key Trials

  1. Michalsen A et al. (2008), n=32 · PMID 18407413 · ASH analysis →
  2. Bachmann S et al. (2018), n=30
Sample sizes of key trials for Thumb Carpometacarpal (CMC-1) OsteoarthritisMichalsen A et al. 200832Bachmann S et al. 201830
Participants per key trial (n). Larger trials generally carry more statistical weight; case series with unspecified counts are omitted.

Contraindications

  • Active anticoagulant therapy (warfarin INR >2.0, DOACs, heparin)
  • Hemophilia or other bleeding disorder
  • Severe anemia (Hb <10 g/dL)
  • Active bacteremia or sepsis
  • Known hypersensitivity to leech salivary proteins
  • Pregnancy (relative — first/third trimester)
  • Immunocompromised state with severe neutropenia
  • Active local infection

Related Conditions

Diese Website stellt Bildungsinformationen bereit und ist weder eine medizinische Beratung noch eine Diagnose oder Behandlungsempfehlung. Die medizinische Blutegeltherapie ist mit klinisch relevanten Risiken verbunden und sollte ausschließlich von qualifizierten Klinikerinnen und Klinikern unter institutionell genehmigten Protokollen durchgeführt werden. Die FDA-510(k)-Zulassung für medizinische Blutegel ist auf bestimmte Indikationen beschränkt; experimentelle und Off-Label-Diskussionen werden entsprechend gekennzeichnet. Für patientenspezifische Beratung wenden Sie sich an eine qualifizierte Gesundheitsfachkraft.

Thumb Carpometacarpal (CMC-1) Osteoarthritis — Hirudotherapy Evidence | ASH