Skin Conditions, General | July 29, 2014 | Author: The Super Pharmacist
Common skin warts, also known as verruca vulgaris, are small round or oval bumps on the skin. While they are often the same color as a person's skin, they may be darker or lighter than the skin around it. A single wart may occur by itself, or they may merge into patches of warts. Verruca vulgaris is caused the human papillomavirus or HPV. Most common skin warts can be recognised by their appearance, but if you have any doubt as to what a skin lesion is, you should have it examined by medical professional.
Salicylic acid can be purchased over-the-counter and applied at home. Higher concentrations of salicylic acid are only available through a physician (and applied in the doctor's office). You should follow the manufacturer's instructions before applying salicylic acid. Ideally, people who wish to treat their warts at home with salicylic acid should soak the area in warm water for 15 min. to soften the skin and then dry the skin completely before applying the treatment. After applying the salicylic acid (it is usually most convenient to do this at bedtime), cover the lesion overnight. In the morning, you can gently file any loose skin with a nail file.
Generally, you should continue the treatment even after signs of the wart are gone so that the virus is completely destroyed. Salicylic acid applied by a physician is a modestly effective treatment for common skin warts and will remove warts more quickly and more reliably than letting them pass on their own.
Success rates with salicylic acid have varied widely, from 0% to greater than 80% in clinical trials. Salicylic acid may be combined with other ingredients to improve success, such as 5-fluorouracil or lactic acid. There is little evidence to suggest that these combined treatments work any better.
5-Fluorouracil was first recognised as a chemotherapeutic for cancer treatment, however it can also disrupt HPV, the cause of common skin warts.
The major limitation with the use of 5-fluorouracil is that it creates inflammation in the skin where it is applied and that inflammation is exacerbated by sun exposure.
It is essential that anyone receiving 5-fluorouracil, keep the treated area covered and away from the sun.
Another chemotherapeutic, bleomycin, has also been used to treat planters warts though in this treatment the drug is injected into the wart rather than use topically.
Tretinoin is a carboxylic acid that is closely related to vitamin A. It is applied to the wart once or twice a day and usually takes several weeks for effect. Like 5-fluorouracil, the treated area must remain covered to prevent sun exposure. Acitretin is a related compound (a retinoid-like molecule) that has been successfully used in the treatment of verruca vulgaris; however, common wart treatment is not an approved use of this drug.
Cidofovir is an antiviral drug that can attack HPV. In a study of patients with common skin warts that had not responded to other forms of treatment, injection of cidofovir directly into the wart completely cleared the wart in 276 out of 280 patients. The authors of the study report that the lesions cleared without relapses but that there was some itching, redness, and darkened skin in the treated area. On the other hand, there were no systemic side effects from cidofovir.
Cryotherapy can be painful and is usually not performed in children because of this. So-called “gentle” cryotherapy is no more effective at treating common skin warts than placebo. “Aggressive” cryotherapy, on the other hand, is more effective than gentle cryotherapy but it is more likely to cause pain, blistering, and bleeding.
Duct tape is a traditional therapy for warts that is usually used on children by parents in the home. The wart should be covered with standard silver duct tape and tape should be left in place for one week. After one week of continuous coverage, the tape is removed to check progress. The duct tape should be re-applied if the wart remains, again for one week. The wart should be gone within four weeks of duct tape treatment. It is unclear whether duct tape is effective at treating common skin warts. A clinical trial in children showed that duct tape was better at healing common skin warts than cryotherapy. Other studies have not shown a clear benefit from duct tape, however. Silver duct tape is used because less “sticky” duct tapes may be less effective, according to clinical trial data.
Cantharidin is a compound that is extracted from insects known to cause blistering bites. This form of treatment may be added to salicylic acid treatment or reserved for cases in which salicylic acid is not effective. While the initial application of cantharidin is painless, blistering and pain may occur over the next 24 hours. In addition, repeated applications may be necessary every two weeks until the wart is gone. If cantharidin is ultimately effective, the treated area should still receive coverage with salicylic acid to destroy any remaining HPV. Importantly, cantharidin is not approved by the FDA however physicians are able to use the topical treatment under their medical license as it is relatively safe and has been approved in other countries (e.g. Canada). To date, there have been no randomised clinical trials to determine if cantharidin is effective in the treatment of verruca vulgaris.
These acids are related to vinegar, but the chloride atoms contained within them make them more potent acids and vinegar.
Bichloracetic and trichloroacetic acid are applied to warts using a wooden toothpick or non-metal applicator once a week. Salicylic acid may speed up the response to these acids. When the wart is well formed, acid application should not be painful; however, when the wart is almost gone and the skin under the lesion is exposed, bichloracetic acid or trichloroacetic acid may cause pain and burning sensation.
Cimetidine is perhaps best well-known as a treatment for heartburn and acid reflux; however, some clinical trials have shown that the histamine receptor blocker may be able to enhance the body's natural immunity to HPV and therefore get rid of common warts. Larger, placebo-controlled and blinded trials failed to show any positive effect of cimetidine. If cimetidine is going to be used, it is likely to be combined with some other wart treatment.
Imiquimod is a topical drug that is commonly used for genital warts, but can be used for common skin warts as well. Imiquimod is not a first-line treatment for common warts, instead is usually used when more common treatments fail. While imiquimod does not cause scarring and is painless, it is expensive and may cause local and systemic side effects. Imiquimod is available in several different concentrations. Higher concentrations of the drug are more likely to remove warts than lower concentrations, but lower concentrations of the drug are less likely to cause side effects.
Intralesional immunotherapy is a wart treatment in which the wart is injected with an antigen that is related to HPV, such as a mumps antigen. The injection may also include a cytokine such as interferon alpha-2b. This injection prompts the immune system to target HPV in the wart. The multistep treatment is effective and is less expensive than imiquimod treatment. Side effects are mild if they occur at all and because it provokes the immune system to target HPV, it may prevent future outbreaks of warts.
Vaccines are now available against certain types of HPV.
While the targeted types are most often associated with genital warts, these vaccines may provide some protection against HPV-induced common skin warts. HPV immunisation is not necessarily a treatment for existing warts (although it has been used successfully for treatment nor is it likely to prevent all common skin warts; Those who received the immunisation may be at least partially protected.
Topical immunotherapy requires treatment by a trained dermatologists. In this wart treatment approach, the patient becomes sensitised to a contact allergen such assquaric acid dibutylester, diphencyprone or ordinitrochlorobenzene. The contact allergen is placed on the skin in an affected area so that the immune system detects it and starts to mount a response to it. After two weeks, when the body has presumably become sensitised to the substance, the contact allergen is placed on the wart. As the immune system attacks the allergen, it also attacks the wart. This treatment approach is reported as more effective than placebo. Because it promotes an immune reaction in the skin, the treated site can become red, itchy, and be left with blisters and skin pigment changes. However, once the body is sensitised to a specific allergen, the treatment may be used for future warts without the need for repeat sensitisation.
Some researchers have had success with photodynamic light therapy in which a substance such as 5-aminolevulinic acid is placed on a wart and then exposed to light. The light energy with the photosensitiser can destroy the HPV. In some cases, laser light energy may be added to enhance the effect. Laser ablation is also an option, but it is not likely better than conventional therapy.
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