Mazzotti reaction

Overview of the Mazzotti reaction in medical practice

The Mazzotti reaction is an acute inflammatory response that occurs in some patients undergoing treatment for certain parasitic infections, particularly those caused by filarial worms. This reaction is named after the Italian physician Luigi Mazzotti, who first described it in the context of treating onchocerciasis.

The Mazzotti reaction can be observed during skin testing for filarial infections.

Causes

The Mazzotti reaction is typically triggered by the administration of diethylcarbamazine (DEC), a medication used to treat filarial infections. When DEC is administered, it kills the microfilariae, leading to the release of antigens that provoke an immune response in the host. This immune response is responsible for the symptoms associated with the Mazzotti reaction.

Symptoms

The symptoms of a Mazzotti reaction can vary in severity and may include:

• Fever
• Itching (pruritus)
• Swelling of the skin
• Rash
• Headache
• Muscle and joint pain
• Lymphadenopathy

In severe cases, the reaction can lead to more serious complications such as hypotension and tachycardia.

Diagnosis

The diagnosis of a Mazzotti reaction is primarily clinical, based on the history of recent treatment with DEC and the presence of characteristic symptoms. Skin testing, such as the epicutaneous test, can sometimes be used to confirm the diagnosis by demonstrating a localized reaction to filarial antigens.

Management

Management of the Mazzotti reaction involves symptomatic treatment to alleviate discomfort. This may include:

• Antihistamines to reduce itching
• Corticosteroids to control inflammation
• Analgesics for pain relief

In some cases, the dose of DEC may be adjusted or alternative treatments may be considered to minimize the severity of the reaction.

Prevention

Preventing a Mazzotti reaction involves careful monitoring and gradual introduction of DEC in patients known to have heavy microfilarial loads. Pre-treatment with corticosteroids may also be considered to reduce the risk of a severe reaction.

Related pages

• Onchocerciasis
• Diethylcarbamazine
• Filarial infection
• Immune response