TABLE 3.

Intralesional therapies for viral warts

TREATMENT MODALITY	DESCRIPTION	MECHANISM OF ACTION	RESPONSE	ADVERSE EFFECTS
Bleomycin6,14,15,16	Antimitotic chemotherapeutic agent	Inhibits DNA synthesis by preventing thymidine incorporation. Ablates the virus by causing intense inflammation and stimulating an immune response to HPV.	The response rates range from 16–94% owing to variations in protocol and study designs in different trials. Recurrence in 15% of cases.	Hemorrhagic eschar (ecchymosis), hyperpigmentation, hypopigmentation, scarring
5-Fluorouracil (5-FU)7,16	Antimitotic chemotherapeutic agent	Interferes with the synthesis of DNA and RNA in infected cells.	45–65% showed complete resolution in 4 weeks. Recurrence in 20% cases.	Pain during and within a day of injection, hyperpigmentation, hypopigmentation, itching
Candida antigen16,17,18	Immunotherapeutic agent	Stimulates a cell-mediated immune response (CMI) leading to recruitment and proliferation of various immune cells and release of cytokines. High prevalence of immunity to Candida in the general population.	24–71% response rate	Pruritus, burning, blistering, peeling, and local erythema and edema, rash, constitutional symptoms
Bacillus Calmette-Guerin (BCG)19	Immunotherapeutic agent	Acquisition of a widespread CMI against HPV as a response to BCG injection.	70% showed complete clearance at the end of 3 months.	Pain, edema, ulceration, scarring, flu-like symptoms

HPV: human papilloma virus; CMI: cell-mediated immunity