Eosinophilic meningitis

Overview

• Angiostrongylus cantonensis (main cause)

• Gnatostoma spinigerum

• Toxocara canis and T. catis : visceral larva migrans

• Baylisascaris procyonis (normal host is the raccoon, Procyon lotor) and Baylisascaris transfuga (round-worm of the bear)

• Taenia solium, though in the majority of neurocysticercoses the cerebrospinal fluid is normal

• Fasciola hepatica and Paragonimus sp. (ectopic localisations)

• Filaria: Loa loa (specially severe reactions after DEC treatment), Meningonema peruzzi (monkey parasite)

• Strongyloides stercoralis in hyperinfection syndrome (beware steroids)

• Trichinella spiralis (massive infection)

• Myiasis due to Callitroga hominivorax or Hypoderma bovis

• Coccidioidomycosis and cryptococcosis

• Non-infectious origins (lymphoma, medications, ventriculoperitoneal shunts)

Eosinophilic meningitis ( syn. Alicata’s disease) is defined as CSF pleocytosis with more than 10% eosinophils or with 10 or more eosinophils per µL. The CSF protein concentration is usually elevated, whereas the glucose level is normal or slightly reduced. Peripheral blood eosinophilia does not correlate with CSF eosinophilia.

Etiology

On a global level, the most frequent etiologies are: Angiostrongylus cantonensis, Gnathostoma spinigerum and neurocysticercosis. One could add cerebral toxocariosis (Toxocara canis) to this list. In the USA, Baylisascaris procyonis and coccidioidomycosis are important entities. Other etiologies of eosinophilic meningitis are cerebral paragonomiasis, neurotrichinosis, cerebral (ectopic) Fasciola hepatica, Strongyloides stercoralis hyperinfection syndrome, infection with Meningonema peruzzi filaria, cerebral/spinal schistosomiasis and cerebral echinococcosis. Reactive meningoencephalitis can occur after the start of DEC treatment of loasis (infection with Loa loa filaria). Non-infectious causes include Hodgkin’s disease, non-Hodgkin’s lymphoma and eosinophilic leukemia. Reactions to ciprofloxacin, ibuprofen, intraventricular vancomycin, gentamycin and iophendylate dye (contrast myelography) as well as foreign bodies such as ventriculoperitoneal shunts or infestation with certain fly larvae (myiasis) are rare causes. Auto-immune diseases and vasculitis should be excluded (post-vaccination encephalitis, SLE, periarteritis nodosa, sarcoidosis, eosinophilic granuloma), as should neurolues and the idiopathic hypereosinophilic syndrome.

Category: Medicine Notes