Autoimmune bullous diseases in non-HIV Kaposi's sarcoma: a retrospective study in a large cohort of patients

Pemphigus: trigger and predisposing factors

Pemphigus is a life-threatening autoimmune blistering disease affecting skin and mucous membranes. Despite its etiopathogenesis remains largely unknown, several trigger and predisposing factors have been reported. Pemphigus is caused by autoantibodies that target desmoglein 1 and desmoglein 3, impacting desmosome function. However, circulating autoantibodies are often the consequence of a precipitating factor that occurs in predisposed individuals. This review aims to describe and discuss almost all trigger and predisposing factors reported as possible or probable cause of the disease. Among the reported trigger factors that may induce or exacerbate pemphigus, we have found of particular interest: drug intake (especially thiol- and phenol-containing compounds), vaccines, infections, as well as some reports about pregnancy, radiations, emotional stress, pesticides and physical trauma. Moreover, we discuss the possible role of food intake in pemphigus onset and particular attention is given to dietary factors containing thiol, phenol and tannin compounds. A trigger factor is "the straw that breaks the camel's back," and often acts together with predisposing factors. Here we discuss how pemphigus onset may be influenced by genetic susceptibility and comorbidities like thyroid diseases, malignancies and other autoimmune disorders. To identify other hitherto unknown trigger and predisposing factors, well designed prospective studies are needed. In this context, future research should explore their connection with the aim to advance our understanding of pemphigus pathogenesis.

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.

Extensive cutaneous iatrogenic Kaposi's sarcoma after bullous pemphigoid treatment with oral methylprednisolone: a rare Chinese case report

Bullous pemphigoid (BP) is an autoimmune disease that requires immunosuppressive therapy. Systemic corticosteroids are considered the standard treatment for moderate-to-severe BP. Kaposi’s sarcoma (KS) is a rare multifocal endothelial tumour that affects the skin, mucosa and viscera. As an angioproliferative disease of obscure aetiopathogenesis and histogenesis, KS is associated with human herpesvirus 8 (HHV-8). This current case report describes a rare occurrence of extensive cutaneous KS in a 60-year-old Chinese male patient after oral methylprednisolone treatment for BP with an emphasis on its pathological characterization. A total of more than 40 nodules were found on his trunk and lower limbs covering more than 20% of his body surface area. Immunohistochemical staining of biopsy samples from the lesion showed the patient was positive for HHV-8, CD31, CD34, XIIIa, ERG and Ki-67. The Epstein–Barr virus test showed the patient tested negative for immunoglobulin (Ig)A and IgM, but was positive for IgG. Immunosuppression associated with the treatment for BP may activate a latent HHV-8 infection and induce the development of KS.

Diagnosis and treatment of classic and iatrogenic Kaposi's sarcoma: Italian recommendations

Kaposi's sarcoma (KS) is a lymphangioproliferative disorder associated with Human herpesvirus 8 (HHV8) infection. Four clinical subtypes are recognized: classic, endemic, epidemic (HIV-related) and iatrogenic. KS diagnosis is based on clinical features, histopathological assessment, and HHV8 serology. Classic KS is usually skin-limited and has a chronic course, while the iatrogenic variant may show mucosal, nodal or visceral involvement. Clinical staging is fundamental to guide the management. Localized disease may be treated with different local therapies, even if there are no randomized trials comparing these different modalities. Aggressive, disseminated KS and cases with visceral involvement usually require systemic chemotherapy, most commonly vinblastine, bleomycin or paclitaxel. Iatrogenic KS needs immunosuppression tapering/withdrawal and, if possible, switch to m-TOR inhibitors in post-transplant KS. The present work by a panel of Italian experts provides guidelines on KS diagnosis and management based on a critical review of the literature and a long and extensive personal experience.