Treatment Options for Genital Warts: Laser vs. Photodynamic Therapy - Obstetrics and Gynecology

Dr. Huang Jianzhong reply Obstetrics and Gynecology

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Treatment
I.
Destruction of the genital tract:
1.
Surgical excision: Under local anesthesia, excision surgery can be performed for solitary lesions, especially for lesions with a broad base (>1 cm), large condylomas, or drug-resistant tumors.
Pathological examination can also be conducted to confirm the diagnosis.
In studies involving adults, the clearance rate for this method ranges from 36-100%, with a recurrence rate of 8-65%, depending on the extent of the lesions.
For extensive lesions, general anesthesia may be required for surgery.
A disadvantage is the potential for scarring.
2.
Electrosurgery: This is the most commonly used method, where lesions are directly cauterized under local anesthesia.
In adult studies, the clearance rate is between 64-94%, with a recurrence rate as high as 50%.
Multiple treatments may be necessary, and patients may experience pain at the treatment site.
During treatment, HPV DNA can aerosolize, necessitating the use of masks and protective equipment to prevent infection in the throat.
3.
Cryotherapy: Liquid nitrogen is applied directly to the lesions using a cryoprobe, causing cell death.
The cost is relatively low, and it is most effective for small, keratinized warts.
However, it may take several weeks to achieve clearance.
In adult studies, the clearance rate is between 54-88%, with a recurrence rate of 21-40%.
In young children, cryotherapy may be intolerable due to pain, and some reports suggest using topical anesthetic creams like lidocaine beforehand.
Side effects of cryotherapy include pain, local skin irritation, and post-healing skin pigmentation changes.
4.
Laser therapy: Carbon dioxide lasers are effective for treating anal and genital warts.
However, there may be pain and scarring, and it is expensive and not easily accessible.
The vaporization of lesions during treatment can aerosolize, requiring masks to be worn.
Laser procedures require considerable skill, thus it is not a first-line treatment.
The clearance rate ranges from 40-100%, with a wide variation in recurrence rates from 4-77%.
II.
Cytotoxic agents:
1.
Trichloroacetic acid (TCA): This is a white, aqueous solution that must be applied weekly directly to the lesions (which will turn white), causing protein coagulation and resulting in 80-90% cell death.
Care must be taken not to apply it to surrounding skin to avoid ulceration.
It has a good efficacy, with a clearance rate in adults of 70-81% and a recurrence rate of 36%.
2.
Podophyllotoxin: Originally derived from the root of a plant, podophyllin has neurotoxic, myelotoxic, and hepatotoxic properties.
Podophyllotoxin (Wartec, Condylox), a more refined compound, has antiviral effects and minimal toxicity, making it suitable for children.
Literature reports a clearance rate of 45-88% for genital warts in children, with a recurrence rate of 12-60%.
Side effects mainly include a burning sensation, with some experiencing pain, skin erosion, edema, itching, and bleeding.
3.
Cidofovir: An antiviral drug that inhibits DNA polymerase of several viruses, preventing viral replication.
It can be administered intravenously for patients with cytomegalovirus-induced optic neuritis and can also be formulated as a cream or gel for topical use.
Reports indicate that 1-3% Cidofovir cream used topically in children aged 6-14 years is effective against drug-resistant, non-genital warts and skin warts.
One report described a 3-year-old child with penile warts treated with 1% Cidofovir cream applied once daily for 5 days, followed by a repeat after 30 days, with no recurrence after one year.
Another report noted a 6-year-old child who, after failed treatments with cryotherapy, imiquimod, and podophyllotoxin, was successfully treated with 3% Cidofovir cream applied twice daily, healing after one week.
Side effects include local irritation.
Cidofovir is effective for anal and genital warts in children, but its high cost limits its use.
III.
Immunomodulators:
1.
Imiquimod: The most commonly used immunomodulator, including 5% Imiquimod cream (Aldara) and 3.75% Imiquimod cream (Zyclara), induces the production of various cytokines, particularly interferon, to clear warts.
In a report by Garland et al., involving 943 adult patients using 5% Imiquimod cream, the lesion clearance rate was 47.8%, with a recurrence rate of 8.8% at 3 months and 23% at 6 months.
In another report by Grussendorf Conen et al., 18 patients aged 9-18 years treated with 5% Imiquimod cream for an average of 5.8 months had a clearance rate of 88.9%.
Although the FDA does not approve its use in children under 12, reports indicate it is safe and effective for young children.
Common side effects include local itching, erythema, local irritation, ulceration, and blistering.
2.
Catechins: The main components of green tea include caffeine, amino acids, lignans, organic acids, proteins, chlorophyll, and polyphenols.
Green tea typically contains higher levels of catechins than black or oolong tea.
Sinecatechins, a type of catechin, can be extracted from green tea and have been approved by the FDA for use in patients over 18 years.
In two reports involving 1004 patients using a 15% ointment three times daily for up to 16 weeks, the clearance rate was 54.9%, with a recurrence rate of 6-11%.
Although the cure rate is high, the need for multiple daily applications over a long period is inconvenient.
3.
Polyphenon E: An ointment derived from green tea with catechin content >85%, approved by the FDA for treating genital warts.
In a study treating 125 men and 117 women with 15% or 10% Polyphenon E ointment for up to 12 weeks, the complete clearance rates were 61% for men and 56.8% for women with the 15% ointment, and 53.8% for men and 39.5% for women with the 10% ointment.
The recurrence rate after 12 weeks was between 10.3-11.8%.
About 7.9% of patients experienced side effects, including hyperkeratosis, skin color changes, transient skin necrosis, allergic dermatitis, and pain.
Similarly, another report involving 277 men and 226 women treated with 15% or 10% Polyphenon E ointment showed a complete clearance rate of 58%, with women clearing at a rate of 65%, outperforming men at 45%.
Approximately 5-18% of patients experienced side effects, including erythema, itching, stinging, ulceration, hardening, and edema.
4.
Cimetidine: An H2 receptor antagonist primarily used to treat peptic ulcers, it also acts as an immunomodulator, enhancing lymphocyte activity and suppressing cell function.
It has been reported to treat skin fungi, herpes, Crohn's disease, and even difficult-to-treat warts.
The typical dosage is quite high, often 30 mg/kg divided into three doses daily for three months.
Reports indicate that four children aged 2-3 years, who failed other treatments for genital warts, were successfully treated with oral Cimetidine, resulting in complete clearance of lesions.
Another report involving 16 children under 16 years treated with oral Cimetidine for warts on the hands and feet showed complete clearance in 9 (56%) and good response (lesion disappearance >75%) in 5 (31%).
Side effects included diarrhea, nausea, abdominal pain, dry mouth, headache, and dizziness, all of which were mild.
This indicates that there is a chance of cure for warts that have failed other treatments.

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Reply Date: 2017/08/01