1st order laboratory parameters – obligatory laboratory tests.
- Small blood count
- Inflammatory parameters – CRP (C-reactive protein).
- Fasting glucose (fasting blood sugar)
- Borrelia serology (see below Lyme disease) – to exclude neuroborreliosis.
Laboratory parameters 2nd order – depending on the results of the history, physical examination and the obligatory laboratory parameters – for differential diagnostic clarification.
- Infectious serology:
- Herpes simplex virus-1 (HSV-1).
- Varicella-zoster virus (VZV; also varicella-zoster virus – suspected zoster oticus, with redness, edema (swelling), blistering in the ear area or on the eardrum, and otalgia (pain in the ear region) being indicative
- Rare viral infections: EBV, CMV, HPV-B19, HIV, enteroviruses, mumps virus, measles virus, rubella virus, adenovirus and influenza virus.
- Rare bacterial infections: Diphtheria (Corynebacterium diphtheriae), ehrlichiosis (bacterium Ehrlichia canis), leptospires, M. pneumoniae, Bartonella henselae, rickettsia (bacteria of the genus Rickettsia; eg, Mediterranean region).
- CSF puncture (collection of cerebrospinal fluid by puncture of the spinal canal) for CSF diagnosis [is controversial; normal findings are present in 80-90% of cases; it is indicated in any case of clinical suspicion of primary non-idiopathic facial nerve palsy (e.g., bilateral (bilateral) facial nerve palsy, severe local pain, or malignant neoplasm)].
