Herpes zoster of the trigeminal nerve with multi-dermatomal involvement: a case report of an unusual presentation.

Background: Herpes zoster, also known as shingles, results from reactivation of the varicella-zoster virus. It commonly presents with burning pain and vesicular lesions with unilateral distribution and affects the thoracic and cervical sites in up to 60 and 20% of cases, respectively. The branches of the trigeminal nerves are affected in up to 20% of cases. Multidermatomal involvement of the trigeminal nerves has been only anecdotally described in immunocompetent subjects.

Case presentation: A 71-year-old previously healthy male presented with grouped vesicular and impetiginized lesions with crusts on the left half of the face of two-weeks duration. The lesions first developed on the left nasal tip and progressively worsened with unilateral appearance of vesicular lesions on the left forehead, face, ala nasi, nasal vestibulum and columella, as well as on the left side of hard and soft palate. The affected edematous erythematous areas corresponded to the distribution of the left ophthalmic (V1) and maxillary (V2) branches of the trigeminal nerve, including the infraorbital and nasopalatine nerves of the maxillary branch responsible for the oral cavity involvement. Viral DNA amplification by polymerase chain reaction confirmed the presence of Varicella zoster virus. The patient was started on oral valaciclovir with rapid recovery.

Conclusions: Among immunocompetent patients, herpes zoster is considered a self-limited localized infection. Our observation provides a rare but paradigmatic example of herpes zoster with involvement of both the ophthalmic and maxillary divisions of the trigeminal nerve in an immunocompetent patient. Immunocompetence status and age-specific screening should be warranted in case of atypical involvement and according to the patient's history, while treatment with antiviral drugs should be rapidily initiated in patients at risk.