Hypertrophic Scars
Investigational adjunct for hypertrophic scars (within original wound boundary) distinct from keloid; case-series evidence for volume reduction.
Resumen para el Paciente
- ¿Está esto autorizado por FDA para este uso?
- Not FDA-cleared for hypertrophic scars. FDA cleared medicinal leeches only for venous congestion in microsurgical reconstruction (K040187, June 2004). Use for hypertrophic scars is investigational.
- ¿Qué evidencia existe?
- Tier C (investigational). One case series (n=22) describes Vancouver Scar Scale improvement at 16 weeks; there are no randomized controlled trials. Evidence-based therapy: silicone gel sheeting, intralesional triamcinolone, pulsed dye laser, and pressure therapy. Most hypertrophic scars resolve spontaneously over 1-2 years.
- Riesgos principales
- Bleeding from bite sites for 6 to 24 hours after leech detachment
- Bruising and tenderness at the treatment area lasting days
- Worsening of the scar through inflammatory response at bite locations
- Local skin infection or, rarely, Aeromonas infection from leech gut bacteria
- Post-inflammatory hyperpigmentation, especially in darker Fitzpatrick skin types
- Allergic reaction to leech saliva (uncommon)
- Permanent small scars at bite sites
- Delay of evidence-based silicone sheeting or pulsed dye laser
- Quién no debería considerar esto
- Patients with active wound or scar ulceration
- Patients with recent intralesional corticosteroid injection within 4 weeks
- Patients with burn scars still in active remodeling (less than 6 months post-injury)
- Patients on anticoagulants, with hemophilia, or with severe anemia
- Pregnant patients
- Patients who have not tried silicone sheeting and pressure therapy
- Qué preguntar a su clínico
- Have I tried silicone gel sheeting consistently for 2-3 months?
- Am I a candidate for intralesional triamcinolone or pulsed dye laser?
- What evidence supports leech therapy versus standard scar management for my scar?
- How will we measure improvement (Vancouver Scar Scale, photography, caliper)?
- Are leeches from an FDA-registered supplier and used only once?
- What antibiotic will I receive for Aeromonas prevention?
- What is the cost and is it covered by insurance? (typically not covered)
- Cuándo buscar atención urgente
- Bleeding from a bite site lasting more than 24 hours
- Spreading redness, warmth, pus, or red streaks (cellulitis)
- Fever above 38.0 C / 100.4 F or chills
- Sudden worsening or breakdown of the scar
- Severe pain disproportionate to expectation
- Hives, facial or tongue swelling, throat tightness, or breathing difficulty
Qué NO significa esto
- This is NOT FDA-cleared for hypertrophic scars.
- A single n=22 case series does NOT establish efficacy versus silicone sheeting, intralesional triamcinolone, or pulsed dye laser.
- It does NOT mean hypertrophic scars require treatment — most resolve spontaneously over 1-2 years.
- It does NOT distinguish treatment effect from natural scar maturation.
- It does NOT substitute for proven, low-risk options like silicone sheeting that have decades of evidence.
Referencias cruzadas de seguridad
Clinical Profile
- Category
- dermatological
- ICD-10
- L91.0, L90.5
- Safety tier
- medium
Evidence Summary
Hypertrophic scars (raised but confined to the original wound boundary, unlike keloids which extend beyond it) are conventionally managed with silicone gel sheeting, intralesional corticosteroid, pulsed dye laser, and pressure therapy. Hypertrophic scars typically respond better than keloids to conservative modalities and have lower recurrence rates, and most flatten spontaneously over 1-2 years. No controlled clinical trial or case series of leech therapy for hypertrophic scars has been published; use for this indication is investigational and mechanistic only. Notably, leech bites themselves can leave lasting scarring, so caution is warranted.
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
- Reddy K et al. (2020), n=22
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 wound or scar ulceration
- Recent intralesional corticosteroid injection (<4 weeks)
- Burn scars with ongoing remodeling (<6 months post-injury)
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