Mazzotti reaction T78.2

The first descriptor was the Mexican parasitologist Luigi Mazzotti (1900-1971) in 1948.

The Mazzotti reaction is an immunological reaction that can occur within a very short time under the first systemic therapy of a nematode disease with the anthelmintic diethylcarbamazine (DEC).

The anthelmintic therapy causes the worms to die in the body of the host. Due to the sudden decay of the worms, increased amounts of parasitic antigens enter the host organism. There they cause an (exuberant) inflammatory immune reaction. Clinically this is manifested with general symptoms such as fever, itching, hypotension, lymphadenitis, arthritis, abdominal pain and headaches. Isolated anaphylactic reactions are described. Overall, the extent of the symptoms seems to correlate with the density of parasite infestation (Francis H et al. 1985). The clinical symptoms usually disappear within 7 days after the start of therapy.

blood eosinophilia and neutrophilia.

Mazzotti originally described the reaction during the systemic treatment of onchocerciasis with diethylcarbamazine. The following other antiparasitic agents may also trigger this reaction: ivermectin, praziquantel and albendazole. Other diseases in whose system therapy a mazzotti reaction can occur are parasitoses caused by pair flukes(bilharzia), dwarf threadworms and trematodes(schistosomiasis). The occurrence of the mazzotti reaction has also been described under the systemic treatment of extensive scabies cases with ivermectin (Ito T 2013).

Remark: The mazzotti reaction should be comparable to the Herxheimer reaction.

1. Francis H et al (1985) The Mazzotti reaction following treatment of onchocerciasis with diethylcarbamazine: clinical severity as a function of infection intensity. Am J Trop Med Hyg 34:529-536.https://www.ncbi.nlm.nih.gov/pubmed/4003668
2. Ito T (2013) Mazzotti reaction with eosinophilia after undergoing oral ivermectin for scabies. J Dermatol 40:776-777.
3. Shorter D et al (2006) Mazzotti-like reaction after treatment with praziquantel for schistosomiasis. Pediatric Infect Dis J 25:1087-1088.