I was working in our minor care side the other day when I picked up a new patient with the chief complaint of “abscess.” When I went in to see the patient, he told me that he has had this problem several times in the past. He described it as painful and itchy. It has always been in the exact same spot, and often times starts small and ends up bigger. This time it is just starting, and has been there about 2 days. He denied being sick recently, but has been under a lot of stress. I was quite surprised when he showed me his back (actual picture above.) What do you think about this “abscess?”
What I noticed was a vesicular rash just left of midline. It was painful. His girlfriend showed me that in the past it extended laterally in what was essentially a band. She pointed out some redness starting just superior and lateral to the vesicles. This area was painful as well.
I diagnosed him with herpes zoster. I placed him on valtrex 1ooomg three times a day for 7 days. I also gave a prescription for percocet for discomfort.
This isn’t a completely typical presentation for zoster. The rash is circular in appearance and doesn’t (yet) appear to follow a particular dermatome. I have seen dermatitis present in a circular and vesicular appearance, but in this case the story isn’t consistent with dermatitis. What do you think of my diagnosis? With the history the patient and the girlfriend give would you feel comfortable making the diagnosis of herpes zoster?
Here are a few important things to remember about zoster:
1. Sometimes patients will present with only pain in a particular dermatome before the rash appears. Keep this in your differential for unexplained pain in a dermatomal pattern.
2. Zoster is less contagious than primary varicella. It is only contagious after the rash appears and until the lesions crust. Risk of transmission is reduced further if lesions are covered.
3. Corticosteroids do not have any effect on post herpetic neuralgia.
4. People with zoster should avoid pregnant women, all premature infants born to susceptible mothers, infants born at <28 weeks’ gestation or who weigh <1000 g regardless of maternal immune status, and immunocompromised persons of all ages until lesions are crusted.
5. Hutchinson Sign refers to the unilateral presence of herpes zoster lesions on the tip of the nose and represents extension of the virus along the nasociliary branch of the ophthalmic division of the trigeminal nerve.
6. Ramsay Hunt syndrome is caused by herpes zoster infection of the geniculate ganglion of the facial nerve. The patient can present with otalgia and facial paresis, other presenting features include vertigo, hearing loss, and tinnitus.
7. Recommended treatment is with either acyclovir (800mg five times a day for 7 days) or valtrex (1000mg three times a day for 7-10 days.)