[Bell's palsy and facial pain associated with toxocara infection]

Toxocarosis involving cranial nerves is extremely rare and almost exclusively concerns the optic nerve. Toxocarosis involving the seventh cranial nerve has not been reported.

A 33y male developed left-sided Bell's palsy two days after left-sided otalgia 6y before. Despite extensive diagnostic work-up at that time the cause of Bell's palsy remained unknown. During the following years Bell's palsy slightly improved but retromandibular pain remained almost unchanged and he developed enlarged lymph nodes along the jugular veins, submandibularly, and in the trigonum caroticum. Re-evaluation 6y later revealed an increased titer of serum antibodies against Toxocara canis and a positive Westernblot for Toxocara canis ES-antigen. Despite absent eosinophilia in the serum, toxocarosis was diagnosed and a therapy with albendazole initiated, with benefit for retromandibular pain, but hardly for Bell's palsy or enlarged lymph nodes. CSF investigations after albendazole revealed a positive Westernblot for antibodies against toxocara but absent pleocytosis or eosinophilia, and negative PCR for Toxocara canis.

Visceral larva migrans due to Toxocara canis may be associated with Bell's palsy, retromandibular pain, and lymphadenopathy. A causal relation between Bell's palsy and the helminthosis remains speculative. Adequate therapy years after onset of the infestation may be of limited benefit.