Pathology · patient case with 3 questions
Shingles, neuralgia and a toothache that is not one
demo: 62-year-old male
chief: Severe pain in the upper right teeth for three days, with no obvious dental cause.
history: Recent bereavement and poor sleep. Chickenpox as a child.
meds: None.
findings: All maxillary right teeth respond normally to pulp testing and are non-tender to percussion. Two days later a unilateral vesicular rash appears on the right cheek and hard palate, stopping abruptly at the midline. Separately, another patient describes brief, electric-shock facial pain triggered by shaving.
Question 1
Shingles results from reactivation of which virus?
Show answer and explanation
Correct answer: D. Varicella-zoster virus
- A. EBV causes infectious mononucleosis and oral hairy leukoplakia.
- B. Coxsackie A causes herpangina and hand, foot and mouth disease, which are bilateral and affect the posterior oropharynx.
- C. HSV-1 causes primary herpetic gingivostomatitis and recurrent herpes labialis, which are not dermatomal and do not respect the midline in this way.
- D. Correct. Primary varicella-zoster infection causes chickenpox, after which the virus remains latent in the dorsal root and trigeminal sensory ganglia. Reactivation, prompted by ageing, stress or immunosuppression, produces herpes zoster: a painful unilateral dermatomal vesicular eruption that stops at the midline.
Question 2
Which virus can produce pain that closely mimics irreversible pulpitis before any rash appears?
Show answer and explanation
Correct answer: A. Varicella-zoster virus
- A. Correct. Prodromal zoster pain precedes the rash by two to four days and can be severe, deep and poorly localised along the affected trigeminal division, which is exactly how it comes to be mistaken for pulpitis. Patients have received root canal treatment and extractions for it. Normal pulp testing across several adjacent teeth with pain that does not localise should raise suspicion.
- B. Hepatitis C has oral associations including lichen planus and sicca symptoms, but not facial neuralgic pain.
- C. CMV causes systemic disease in the immunocompromised and occasional oral ulceration, but not this prodromal neuralgic pain.
- D. HPV causes papillomas, condylomas and focal epithelial hyperplasia, all painless.
Note: The practical rule: before irreversible treatment, confirm that the pain localises to one tooth with a reproducible pulpal and periapical picture. Unilateral non-localising pain with normal testing warrants a pause.
Question 3
Trigeminal neuralgia most commonly affects which divisions?
Show answer and explanation
Correct answer: A. V2 and V3
- A. Correct. The maxillary and mandibular divisions are affected in the great majority of cases, which is why these patients so often present to a dentist first and may undergo unnecessary treatment. V1 alone is involved in only about 4 percent. The pain is brief, lancinating and triggered by light touch, chewing, shaving or cold air.
- B. V1 involvement is uncommon, so this pairing is not the typical pattern.
- C. The same objection applies; V1 is the least affected division.
- D. Isolated V1 neuralgia is rare and should prompt investigation for a secondary cause.
Note: Bilateral trigeminal neuralgia, or onset in a young patient, raises the possibility of multiple sclerosis and warrants imaging.