Iatrogenic Kaposi's sarcoma induced by rituximab and corticosteroid treatment for pemphigus vegetans in an HIV-negative patient

Rituximab-Induced Kaposi Sarcoma in HIV-Negative Patients: A Narrative Review

Kaposi sarcoma (KS) is a low-grade mesenchymal angioproliferative disorder that requires infection with human herpes virus 8 (HHV-8) for it to develop. It is commonly seen in HIV-positive patients and rarely in immunosuppressed HIV-negative patients. Rituximab is a monoclonal anti-CD20 chimeric murine/human immunoglobulin G antibody used to treat B cell lymphoproliferative diseases as well as a variety of autoimmune disorders. Several cases of iatrogenic Kaposi sarcoma (iKS) have been described after rituximab treatment. The purpose of this narrative review is to identify the presence of common clinical characteristics among rituximab-induced KS patients that could facilitate better management of this rare condition.

Kaposi's sarcoma in a patient with pemphigus vulgaris mimicking exacerbation of pemphigus

BACKGROUND

Kaposi's sarcoma (KS) is a rare multifocal angiogenic tumor often seen in immunocompromised setting such as acquired immunodeficiency syndrome (AIDS) or organ transplantation recipients. Pemphigus vulgaris (PV) is a rare blistering disorder with mucocutaneous involvement for which immunosuppressive therapy has long been the core of treatment. Iatrogenic form of KS has been reported infrequently in pemphigus patients as a result of long-term immunosuppressive therapy.

CASE

We describe a 39-year-old male patient with confirmed diagnosis of PV who developed KS after receiving immunosuppressive agents for his pemphigus. KS was initially localized to the oral cavity with features mimicking exacerbation of his pemphigus.

CONCLUSION

This interesting case of KS suggests that dermatologists visiting patients with pemphigus with discomfort in the oral cavity should have a high degree of awareness and consider other differential diagnoses along with merely an exacerbation of PV.