Arthus reaction

Arthus reaction
Synonyms	Localized immune complex hypersensitivity
Pronounce	N/A
Specialty	N/A
Symptoms	Edema, erythema, necrosis
Complications	Tissue necrosis, ulceration
Onset	4–12 hours after exposure
Duration	Variable, depending on severity
Types	N/A
Causes	Immune complex deposition
Risks	Repeated exposure to antigen
Diagnosis	Clinical evaluation, skin biopsy
Differential diagnosis	Serum sickness, allergic reaction
Prevention	Avoidance of known antigens
Treatment	Corticosteroids, antihistamines
Medication	N/A
Prognosis	N/A
Frequency	Rare
Deaths	N/A

The Arthus reaction is a type of hypersensitivity reaction classified as a type III hypersensitivity reaction. It is named after the French scientist Nicolas Maurice Arthus, who first described it in 1903. The Arthus reaction is a localized response to the injection of an antigen into the skin of an individual who has high levels of circulating antibodies to that antigen.

Mechanism

The Arthus reaction is characterized by the formation of immune complexes in the walls of the local blood vessels. These immune complexes are formed by the binding of antibodies to the injected antigen. The immune complexes activate complement, leading to the recruitment of inflammatory cells, which cause damage to the local tissues. The reaction typically occurs 4 to 12 hours after the injection of the antigen and is characterized by severe pain, swelling, redness, and occasionally necrosis of the skin and underlying tissues.

Clinical significance

The Arthus reaction is a model for many types of immune complex-mediated hypersensitivity reactions. These include certain forms of glomerulonephritis, vasculitis, and rheumatoid arthritis. Understanding the Arthus reaction can therefore help in understanding the pathogenesis of these diseases.

See also

• Hypersensitivity
• Immune complex
• Complement system
• Inflammation
• Glomerulonephritis
• Vasculitis
• Rheumatoid arthritis