Definição: Grupo alargado de doenças caracterizado pela presença de alguns a múltiplos eosinófilos e/ou evidência de desgranulação de eosinófilos da pele e/ou mucosas
Existem 2 tipos de dermatoses com eosinófilos
Dermatoses com eosinófilos, mas que não são o achado principal da doença
Dermatoses em que os eosinófilos caracterizam a doença e não pertencem a outras características nosológicas → dermatoses eosinofílicas
Mechanism (of the group)
Remains unclear
Appears to be a reactive syndrome characyerized by activation of the immune system, leading to preferential production of Th2 cytokines, primarily IL5, the main factor involved in eosinophils
Eosinophils
Involved in the protection from parasites
Bind to IgE and become activated
Possess weak phagocytic properties → may act as antigen presentic cells
Harbour granules that contain
major basic protein (MBP),
eosinophil cationic protein,
eosinophil peroxidase,
eosinophil-derived neurotoxin
→ to kill parasites together with prostaglandins, leukotrienes and cytokines
Can activate mast cells and basophils to release histamine
Also produce Histaminase to stop intense histamine mediated reactions
Important role in the pathogenesis of allergic reactions
Dermatoses com eosinófilos, mas que estes não são o achado principal