Herpes zoster oticus, a term denoting the infection of the ear by varicella zoster virus (VZV), is one of the many clinical types of VZV described in the literature. In addition to ear pain and the characteristic vesicular eruptions on the skin, herpes zoster oticus frequently manifests with facial nerve palsy, and the term Ramsey Hunt syndrome is often used as a synonym. The diagnosis is made primarily on the basis of clinical criteria.
Herpes zoster oticus (HZO) is one of the clinical syndromes which develops after the initial colonization of varicella virus in the ganglia of the cranial nerves  . Defined as an infection of the ear that appears after reactivation of VZV from the geniculate ganglion, this clinical entity is now a rare occurrence in clinical practice, and is predominantly encountered among elderly individuals   . The clinical presentation comprises of a typical rash in the form of erupting vesicles in the external auditory canal, the eardrum, pinna, and cavum conchae, whereas otalgia (ear pain that is described as severe), tinnitus, vertigo, and even hearing impairment are reported     . Higher frequencies are more severely affected than lower frequencies, and in a number of patients, hearing loss can be severe enough to result in deafness  . Paresis of the facial nerve on the ipsilateral side (manifesting as unilateral facial paralysis and asymmetry of the face) quite often accompanies the typical features of herpes zoster oticus and the term Ramsay Hunt syndrome (named after the first physician who described the condition) is used for this condition in the literature   . Other notable symptoms are nausea, vomiting, nystagmus, and distribution of lesions in the oral cavity, while pain may spread throughout the face and neck area  .
With a thorough clinical workup, herpes zoster oticus can be easily diagnosed. Firstly, a detailed patient history should assess the presenting complaints, their duration, as well as severity, but the role of a properly conducted physical examination is perhaps of essential importance. A full inspection of the auditory canal and the face is sufficient to identify vesicular rash that is highly suggestive of a VZV infection. Furthermore, if facial paralysis is suspected, a neurological examination including the assessment of cranial nerves will detect features of facial nerve palsy . Weakness of the muscles of facial expression supplied by the facial nerve will manifest as a drooping lower lid, incomplete eye closure, reduced movement of the lip and the forehead, and facial asymmetry . Thus, a combination of clinical findings is usually enough to make the diagnosis of herpes zoster oticus or Ramsay Hunt syndrome, but in some patients, the findings may be nonspecific and microbiological studies should be performed in those cases. Detection of high antibody titers is a useful initial method, but testing of samples obtained from swabs or ear fluid by polymerase chain reaction (PCR) is a highly recommended diagnostic tool that carries a high rate of success   .