Fogo selvagem (FS) and pemphigus foliaceus (PF) possess pathogenic IgG anti-desmoglein 1-(Dsg1) autoantibodies. Although PF occurs sporadically, FS is endemic in Limao Verde (LV), Brazil (3.4% prevalence). IgM anti-Dsg1 were detected in 58% FS LV patients (n=31), 19% of FS patients from Hospital-Campo Grande (n=57), 19% from Hospital-Goiania (n=42), 12% from Hospital-Sao Paulo (n=56), 10% of PF patients from United States (n=20), and 0% of PF patients from Japan (n=20). Pemphigus vulgaris (n=40, USA and Japan), bullous pemphigoid (n=40, USA), and healthy donors (n=55, USA) showed negligible percentages of positive sera. High percentages of positive IgM anti-Dsg1 were found in healthy donors from four rural Amerindian populations (42% of 243) as compared with urban donors (14% of 81; P<0.001). More than 50% of healthy donors from LV (n=99, age 5-20 years) possess IgM anti-Dsg1 across ages, whereas IgG-anti-Dsg1 was detected in 2.9% (age 5-10 years), 7.3% (age 11-15 years), and 29% of donors above age 16. IgM anti-Dsg1 epitopes are Ca2+ and carbohydrate-independent. We propose that IgM anti-Dsg1 are common in FS patients in their native environment and uncommon in other pemphigus phenotypes and in FS patients who migrate to urban hospitals. Recurrent environmental antigenic exposure may lead to IgM and IgG responses that trigger FS. JID JOURNAL CLUB ARTICLE: For questions, answers, and open discussion about this article please go to http://network.nature.com/group/jidclub.

Pemphigus foliaceus (PF) and pemphigus vulgaris (PV) are autoimmune blistering diseases characterized by autoantibodies against desmoglein (Dsg)1 and Dsg3, respectively. The role of classical cadherins as immunological targets of pemphigus autoantibodies is unknown. In this study, we tested the reactivity of sera from patients with PF, Fogo Selvagem (FS), and PV by immunoprecipitation coupled with immunoblotting (IP-IB) and ELISA techniques using a baculovirus-expressed ectodomain of E-cadherin. By IP-IB, anti-E-cadherin reactivity was detected in all tested sera of PF (n=13) and FS (n=15) patients, and in 79% of mucocutaneous-type PV patients (n=33), but in none of the mucosal-type PV patients (n=7). By ELISA, anti-E-cadherin IgG was detected in most pemphigus sera that produced strong E-cadherin bands by IP-IB. The immunoreactivity of PF/FS sera with E-cadherin was also demonstrated by IP-IB using human epidermal extracts. However, immunofluorescence staining of A431DE cells (E-cadherin positive, Dsg1 negative) with pemphigus sera showed negative results. Immunoadsorption and competitive ELISA analysis suggest that most of the anti-E-cadherin antibodies cross-react with Dsg1, whereas others may represent independent antibodies that do not cross-react with Dsg1. The functional relevance of these anti-E-cadherin IgG autoantibodies detected in these pemphigus sera remains to be defined.

Plaque-like myofibroblastic tumor of infancy (PMTI) was first reported in 2007. The first two cases described large, plaque-like tumors presenting in infancy with microscopic features consistent with dermatofibroma but with immunohistochemical features of myofibrocytic lineage. We present three additional cases of PMTI, the first cases reported since the initial two cases, and describe additional clinical features of this condition, including presentation in early childhood as opposed to infancy, development of ulceration, and aggressive growth. We propose shortening the name of this condition to plaque-like myofibroblastic tumor because presentation can occur in infancy or in early childhood.

Fogo selvagem (FS), the endemic form of pemphigus foliaceus (PF), is an autoimmune blistering disease characterized by autoantibodies against desmoglein 1. The Terena reservation of Limao Verde in Mato Grosso do Sul, Brazil, is a previously identified focus of disease. Autoantibodies against desmoglein 3 (Dsg3) have also been detected in sera from patients with FS. In an effort to further characterize the serological, geographical, and clinical epidemiology of the disease, we sought to determine the prevalence of anti-Dsg3 autoantibodies in sera from normal subjects living outside of and in an endemic area using an ELISA. Anti-Dsg3 antibodies were detected in 53 of 146 normal subjects from Limao Verde (36%), and in eight of 140 normal subjects from surrounding areas (6%). A significant trend was observed in the proportion of positive tests relative to distance from the endemic area (P < 0.001). Our seroepidemiological observations support the concept that the likely environmental trigger of the antibody response in FS is located in this endemic area, and that the population at risk to develop FS may also be at risk to develop an endemic form of pemphigus vulgaris as reported by our co-investigators from Brasilia.

Treatment-resistant warts are a common and frustrating problem for patients, parents, and providers alike. No wart treatment is uniformly effective. Indeed, well-designed randomized controlled trials are sorely needed to establish the true efficacy of all wart therapies. Treatment should be tailored to each individual patient. Although none of the immunologically-based treatments listed above (see Table, page 377) is FDA-approved for warts, they provide the treating physician with options for patients with warts that are resistant to standard treatments.