Intralesional Candidal Antigen Versus Intralesional Zinc Sulphate in Treatment of Cutaneous Warts, A Randomized Clinical Trial

Forty percent of children spontaneously clear in two years without treatment owing to natural immunity [ 2,3.]. However, warts can persist and increase in size and number [2] .

Warts may reflect a localized or systemic cell-mediated immune (CMI) deficiency to HPV. Various reasons like lack of production of memory T cells to target HPV infection, failure of clonal expansion of lymphocytes to adequate stimulation, inability of T lymphocytes to traffic to sites of infection and weak effector response mechanism have been hypothesized. [4] .] Consequently, warts are particularly exuberant in patients with Hodgkin's disease, AIDS and those on immunosuppressant [ 5 ].

The conventional modalities in treatment of warts include destructive therapies such as salicylic acid, trichloroacetic acid, cryotherapy, silver nitrate, phenol, canthiridin, electrocautary, surgical interventions and lasers; antiproliferative agents such as bleomycin, vitamin D analogs, podophyllin, and 5-fluro uracil; antiviral agents such as cidofovir and retinoids. Because of the cumbersome nature of these procedures and a high risk of recurrence, immunotherapy is becoming more and more popular, especially in the treatment of refractory cutaneous and genital warts [ 6 ] . It enhances recognition of the virus by the immune system. This allows not only clearing of the treated wart, and frequently warts at distant anatomic sites, but also may prevent future clinical infection [ 7 ] .

Immunotherapy in warts can be administered by various methods. The first method is topical application of certain inorganic molecules that are capable of eliciting a contact hypersensitivity reaction with secondary activation of an immunological response [ 8 ] . A second modality is the use of oral immune modulators such as cimetidine and zinc(10mg/kg/day for 2months) [ 9 , 10 ] .

A third method is Intralesional injection of immunotherapeutic agent that utilizes the ability of the immune system to mount a delayed type hypersensitivity response to various antigens and also the wart tissue leading to production of Th1 cytokines which activate cytotoxic and natural killer cells to eradicate HPV infection. This clears not only the local warts but also distant warts unlike traditional wart therapies [ 11 ] .