Treatment of Multiple Recalcitrant Warts in an Immunocompromised Patient Using Purified Protein Derivative (PPD) Injection: A Case Report

BACKGROUND Warts are common cutaneous viral infections primarily caused by human papillomavirus (HPV). They occur in all age groups, with immunocompromised individuals being particularly susceptible. Patients with compromised immune systems, such as those with acquired immunodeficiency syndrome (AIDS), organ transplant recipients, and individuals on immunosuppressive therapies, are at a higher risk of developing warts. These patients are also more likely to have severe and persistent warts, often necessitating multiple treatment approaches. Conventional therapies such as cryotherapy, laser ablation, and topical treatments often yield suboptimal results in this population due to their compromised immune response. Although intralesional immunotherapy, such as purified protein derivative (PPD), has been shown to stimulate a systemic immune response and facilitate wart clearance, its use in immunosuppressed individuals remains under-reported and under-utilized in clinical practice. CASE REPORT We report the case of a 70-year-old woman with a history of immunosuppression who presented with multiple recalcitrant warts on her left hand. Due to the persistence of lesions despite previous treatments, she received PPD injection sessions in a single lesion. Remarkably, all of her warts regressed completely within 6 weeks, with no recurrence observed during follow-up. No adverse effects were reported, highlighting the safety of this approach. CONCLUSIONS This case underscores the potential of PPD immunotherapy as an effective, safe, and well-tolerated treatment modality for warts in immunocompromised patients. Given its immunostimulatory properties and ability to induce systemic clearance, PPD should be considered a valuable alternative for managing refractory warts in this high-risk population. Further studies are warranted to establish standardized protocols and optimize its clinical application.