Immunotherapy and bleomycin are only used if all other treatment fails. Immunotherapy triggers your immune system to destroy the virus causing the wart. Because some of the substances used for immunotherapy are expensive, dangerous, or require specialized handling, such treatment is considered only after other methods have failed.
Immunotherapy options include contact sensitizers, imiquimod, and interferon.
The following table compares these treatments for warts.
Treatments for warts
| Type of treatment|| Advantages|| Disadvantages|
Contact sensitizers (immunotherapy)
- Contact sensitizers attack the virus that causes the wart.
- One review of studies reports that the sensitizer DNCB removed warts in 80% of the people using it, compared to 38% in people using a placebo.1
- Contact sensitizers have potential for causing severe allergic reaction.
- They are not widely used because of cost and risks to doctors.
- They are not recommended for pregnant women.
- Imiquimod is applied at home.
- It is considered effective treatment for genital warts and is being used more in other types of warts.
- It attacks the virus that causes the wart.
- There is little information on its effectiveness for nongenital warts.
- It can cause relatively mild skin irritation, burning, and blistering.
- It is expensive.
Interferon injection (immunotherapy)
- Interferon attacks the virus that causes the wart.
- Interferon is usually injected into the wart.
- It is considered experimental and is not widely available.
- Bleomycin is injected into warts that have been resistant to other treatments.
- There is no consistent evidence of bleomycin's effectiveness.2
- It causes pain during and after injection into a wart, and is usually used as a last resort.
- It can cause scarring, nail damage, and skin color changes.
- It is expensive.
- It is toxic and not recommended for children and pregnant women.