Background and Aims A ten year-old girl with hyper IgE syndrome caused by DOCK8 mutation was admitted to our hospital due to neuropsychiatric symptoms. Cranial MRI revealed multifocal cerebral lesions. Our aim was to clarify the etiology of these lesions by extended microbiology tests and comprehensive search in the literature then provide her with proper treatment options.

Methods Multiple blood and cerebrospinal fluid samples and were examined for bacterial and fungal culture, Aspergillus and Cryptococcus antigen, HSV, CMV, Mycobacterium and Toxoplasma PCR, panfungal PCR and for Toxocara and E. hystolytica serology. Brain biopsy was also done for histology, bacterial and fungal culture.

Results All diagnostic assays showed negative results therefore causative agents could not be identified For treatment, ceftriaxon and metronidazole combination was initially used accompanied by slight clinical and neuroradiological progression. Considering the possible presence of vascular brain lesions, high dose parenteral steroid treatment was introduced together with preemptive parenteral voriconazol therapy. Further progression in the clinical and radiological status was observed. Although there is no report of cerebral toxoplasmosis in this disorder, empirical antitoxoplasma treatment was initiated with significant clinical improvement and radiological regression after 6-week therapy. Retrospective tests of CSF for Toxoplasma serology showed IgG titer increment.

Conclusion To our knowledge this is the first paper on cerebral toxoplasmosis in hyper IgE syndrome to date. In case of cerebral lesions in these patients Toxoplasma reactivation should be considered inspite of negative Toxoplasma PCR and antitoxoplasma treatment sould be introduced in the absence of other etiologic factor.