Induced pemphigus

Abstract

The reports of induced pemphigus have multiplied over the last 10 years. Several heterogeneous factors, such as drugs (penicillamine, pyritinol, captopril, rifampicin, etc.), physical agents (burns, UV, and ionizing radiation) and viruses, can play an inducing role. Usually, the disease is preceded by prodromal, non-specific lesions. The full-blown stage shows features of pemphigus foliaceus, erythematosus or herpetiformis. Histologically, acantholytic splits mostly occur at the highest malpighian layers. Intercellular antibodies and frequently concomitant other auto-antibodies are found in the serum, the titre of the former usually being low and unrelated to the severity or course of the disease. The biological progress is variable and ranges from rapidly and definitively healing cases (induced pemphigus proper) to others which, in spite of the elimination of the inducing factor, self perpetuate just like true pemphigus (triggered pemphigus). Pathogenic hypotheses are based on the act that some inducing factors can alter the antigen distribution on keratinocyte membranes and/or interfere with immune surveillance by impairing T-suppressor cells.

Novel Mechanisms of Target Cell Death and Survival and of Therapeutic Action of IVIg in Pemphigus

“…86 Interestingly, UV irradiation up-regulates remarkably immunohistochemical visualization of calpain in the epidermis. 87 UV irradiation is a common culprit of pemphigus exacerbation 88 that has been shown to induce acantholysis in patients' skin. 89 Among calpain substrates are also proteins involved in apoptosis (caspase 3, Bax, Bcl-XL, and Bid).…”

Precautions and Suggestions for Pemphigus Patients

“…Their involvement in the pathomechanisms leading to the outbreak of pemphigus has often been suspected on the basis of circumstantial evidence, but sometimes it can be demonstrated with certainty (e.g. penicillamine- induced pemphigus, paraneoplastic pemphigus) [4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]. As for certain drugs, their potential of provoking acantholytic changes has been confirmed by several experimental investigations [13].…”

“…In the last two decades there has been a growing body of evidence that drugs may exacerbate, trigger or even cause pemphigus in predisposed subjects [4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]. In fact, drugs remain by far the most implicated exogenous factor in pemphigus induction.…”

“…Induced pemphigus proper refers to a condition where exogenous factors play a major role so that the disease regresses after the inducing factor has been eliminated, even without treatment. In triggered pemphigus, endogenous factors are more important and the inducing factors seem only to trigger, in a casual and nonspecific manner, a disimmune mechanism previously programmed and ready to be set off so that, in spite of elimination of the inducing factor, the disease self-perpetuates [4]. Inducing factors are numerous and heterogeneous (table 1).…”

Dermatoses bolhosas auto-imunes

“…É recomendável o tratamento para estrongiloidíase, mesmo com exame parasitológico de fezes negativo em pacientes com PV tratados com corticóide. Recomenda-se proteção solar aos portadores de PV, porque as lesões podem ser exacerbadas pela luz ultravioleta, 59 e lembra-se que a gravidez pode precipitar ou agravar o PV. 60,61 Concluindo, o futuro próximo indica que o tratamento com biológicos poderá ser a terapêutica de primeira escolha no tratamento do PV grave, evitando assim o uso de altas doses de corticóides e terapias imunossupressoras.…”