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Fogo selvagem

What is fogo selvagem?

Fogo selvagem, also known as endemic foliaceous pemphigus, is a autoimmune bullous disease It is a variant of the leaf pemphigus with a single epidemiological profile.

Who receives fogo selvagem?

Fogo selvagem is the most predominant in rural areas of the southern and mid-western states of Brazil, such as Goiás, Mato Grosso do Sul, Paraná, São Paulo and Minas Gerais. Cases have also been reported in Tunisia, Peru, Paraguay, El Salvador and Colombia. It most often affects children and young adults.

Fogo selvagem is closely related to poverty and malnutrition and has a higher incidence in areas near rivers and streams. Fogo selvagem is associated with the human White blood cell antigen complex (HLA), indicating a genetic predisposition to the disease

What causes fogo selvagem?

Fogo selvagem is an autoimmune disease in which an individual's immune system reacts against keratinocytes and desmosomes that make up the skin

In reaction to the foge selvagem, the body produces immunoglobulin G4 (IgG4) antibodies that bind to the desmosomal protein desmoglein-1 (Dsg1). This causes superficial keratinocytes of the epidermis separate from each other and fill with fluid, causing the characteristic blisters.

The exact Pathogenesis de fogo selvagem is not known, but it is believed that a combination of genetic and environmental factors is involved. HLA-DRB1-0404, 1402 or 1406 expression alleles It is found in patients with fogo selvagem, which suggests a genetic susceptibility. It is presumed that a salivary protein of a blood-sucking insect like the black fly (Simulium nigrimanum) triggers the autoimmune response as blackfly bites have been found to be more common in fogo selvagem patients.

What are the clinical characteristics of fogo selvagem?

The classic lesions of fogo selvagem are superficial blisters or vesicles that progress for weeks or months. Its features include:

  • Blisters and lesions, which break easily when rubbing the skin.
  • Superficial vesicles, which progress for weeks / months.
  • Erosion and crust in seborrhea areas, including scalp and face, neck and upper trunk
  • Burning sensation on the skin, reflected in the name: fogo selvagem means forest fire in Portuguese.

What are the complications of fogo selvagem?

If not treated, complications can include:

  • Growth retardation and dwarfism in children
  • Azoospermia (infertility in men)
  • Increased risk of viral infections.

These complications are less likely to occur if the disease is treated right away.

How is fogo selvagem diagnosed?

The diagnosis of fogo selvagem is based both on the predominance of the disease and its characteristic blisters and a positive Nikolsky sign (where gently rubbing the affected skin causes a blister to form).

Skin biopsy shows acantholysis of the upper epidermis, which often results in a subcorneal cleft (where a loss of accession between keratinocytes creates leads to the division of the skin layer). The subcorneal cleft increases in size and may detach, with or without bulla training. Other histological findings may include papillomatosis, hyperkeratosis and parakeratosis. Mild lymphocytic infiltration may be present.

Direct immunofluorescence shows epidermal intercellular fluorescence - mainly anti-IgG or anti-C3 autoantibodies.

An ELISA test (rDsg1-His) can be used to detect intercellular autoantibodies of fogo selvagem.

Which is the differential diagnosis for fogo selvagem?

Other skin conditions may be considered in a patient with superficial blisters of the scalp, face, neck, and upper trunk, such as:

  • Seborrheic dermatitis
  • Cutaneous lupus erythematosus.

by generalized blisters, consider:

  • Pemphigus vulgaris
  • Other causes of erythroderma, like psoriasis or atopic dermatitis.

What is the treatment for fogo selvagem?

Fogo selvagem is treated with systemic corticosteroids such as prednisone or prednisolone, to which most patients respond well. Immunosuppressive agents can be added, such as:

  • Azathioprine
  • Mycophenolate

  • Cyclophosphamide

What is the result for fogo selvagem?

With proper treatment, the forecast de fogo selvagem is good without long term aftermath.