Intralesional Cidofovir for the Treatment of Recalcitrant Warts in the Pediatric Immune-suppressed Population.

Inclusion Criteria: * 1\. The first cohort will include a total of 4 patients ages 12 to 17. After all tests indicate treatment safety, the second cohort will be recruited and will include patients ages 8 to 17.Patient is in immune-suppressed status by one of the following: 1. Primary immunodeficiency, which may include but is not limited to the following: 1. Chronic Granulomatous Disease (CGD) 2. Common Variable Immunodeficiency (CVID) 3. DiGeorge Syndrome (DGS) 4. Selective IgA Deficiency 5. Severe Combined Immunodeficiency (SCID) 6. X-Linked Agammaglobulinemia (XLA) 2. Pharmacologic immune-suppressed status from medications including but not limited to: 1. prednisone 2. cyclosporine 3. azathioprine 4. tacrolimus/ FK506 5. mycophenolate mofetil 6. sirolimus 2\. Patient has history of clinically-significant warts that are either refractory to standard therapy or for which standard therapy is contra-indicated or unreasonable 3. Patient has a total wart burden of at least 1cm 4. Patients must have tried and failed at least 2 other conventional treatments for cutaneous warts, including but not limited to: * cryotherapy * topical salicylic acid * imiquimod * topical 5FU * pulsed dye laser therapy * sinecatechins * tretinoin or other topical retinoid * intralesional candida injection * bleomycin * electrocautery * topical cidofovir cream or gel There will be a one month washout period for all treatment modalities, with the exception of intralesional candida, which will be 3 months. 5\. Patient desires ongoing treatment of their warts 6. Patient and/or their parent/guardian consents to participating in this study Exclusion Criteria: <!-- --> 1. Treatment area is either ulcerated, secondarily infected, or significantly inflamed 2. Treatment area is on face or groin area 3. Patient is pregnant, attempting to become pregnant, or lactating 4. Patient reports active kidney disease, or chart review reveals recent serum creatinine ≥1.5mg/dL or a history of renal disease/insufficiency or history of diabetes 5. Patient is currently receiving a nephrotoxic medication 6. Patient has history of hypersensitivity to cidofovir 7. Patient is severely ill and/or hospitalized 8. Patient is receiving chemotherapy