More About Intralesional Injections
There are a variety of substances that can be injected intralesionally in an effort to stimulate the immune system. Injections include antigens such as the measles, mumps, and rubella (MMR) vaccine; Candida albicans; Bacillus Calmette–Guérin (BCG), and Mycobacterium indicus pranii. Interferon has also been used as an injectable in an effort to encourage nearby cells to heighten their anti-viral defenses.
How does this treatment work?
Specific function depends on the substance that is injected, however the basic premise is simple: Inject something foreign into the lesion and trust that the body will (a) detect the foreign substance and (b) initiate an immune response that should alert the body to the presence of the HPV virus. The resulting immune cascade should then kill the HPV virus, thus eliminating the warts. These substances can also have viral defense stimulating function.
How effective is this treatment?
There have been several randomized, controlled trials involving bleomycin as the intralesional injection, however the outcomes have varied significantly making it difficult to assess as a treatment option. Most clinicians will reserve this treatment to a second line therapy to consider if other treatments have failed.
What can patients expect when receiving this treatment?
Typical Treatment Protocol:
- The wart does not need to be debrided prior to treatment
- The substance selected is injected into typically the largest wart if more than one are present.
- Based on reaction, substance injected and clinician preference, the patient will be brought back for additional injections.
- Needle injection pain is the primary source of pain during the procedure
- Post injection pain results from reaction and swelling
- Dependant on the substance injection, some irritation might present
- Swelling and pain is to be expected
- The wart itself may not show visible signs of improvement, but should be thinning if the virus is being attacked.
- Swelling and Pain within 24 and 72 hours after injection before a black thrombotic eschar forms.
- Raynaud’s phenomenon is a concern for treated digits
- The nail may become dystrophic or be completely lost
- Bleomycin may also cause lymphangitis and hyperpigmentation
Where can I receive this treatment?
As a less commonly used treatment option, not all clinicians will have the option or will elect to treat with injections. If you would like to be treated with an injection, you should call ahead to assess availability, however consultation is recommended prior to confirming an appropriate treatment.