December 30th, 2014

Common Curbsides: The Patient with “Recurrent Zoster”

Just in time for the New Year celebration, here’s a curbside consult I’ve received several times, probably because the answer isn’t in most textbooks. As usual, the actual question is slightly edited, as well as lightly (and affectionately) annotated:

Hey Paul [I like that casual salutation] — Quick question [of course] — I have a patient with a history of irritable bowel, otherwise well, who had shingles on her lower back a few years ago, approximately L5-S1 [love those dermatome maps]. It was pretty bad, but ultimately improved on Valtrex. Since then she’s contacted me several times with recurrent zoster in the same distribution, each time it improves with more Valtrex. She’s not immunocompromised, HIV negative, not on steroids, etc.
Should she be on chronic suppressive treatment? If so, what drug and what dose? And how long should she be on it? Any role for the shingles vaccine? [Hey — you said “Quick question” — not “questions”! That will cost you.] She’s only 42. [Agree with the “only 42”; that’s very young, at least compared to some ID specialists who have blogs.]
Gracias! [Espanol! Excelente!],
Juanita [not her real name, but it matches with the Spanish expression of gratitude]

There’s a reason doctors have questions about their patients with frequently recurring zoster — it’s because the entity doesn’t really exist. That makes finding guidance for management extremely difficult!

Even a single recurrence is rare — an outbreak may boost native immunity — which is why patients with a history of shingles were not included in the pivotal study of the zoster vaccine.

Recurrent zoster is rare enough that some question whether it makes sense to give the vaccine to people with a history of shingles, though in my experience these are understandably the patients with the greatest motivation to get vaccinated, so I’m glad the guidelines do endorse this practice. And one population-based study did find that a single recurrences of zoster occurred in people with a history of shingles at about the same rate as an initial episode. Prolonged pain was a risk factor for having another episode.

So if it isn’t recurrent zoster most of these patients are experiencing, what is it? So far all of the cases I’ve been referred have been one of these three things:

  1. Herpes simplex. This is far and away the most common mimicker. Obviously the skin lesions can look a whole lot like zoster, and since HSV is usually found in the oral or anogenital areas, the clinician and patient just don’t think about it when clusters of vesicles crop up somewhere else. (It’s what our very young patient summarized above had, of course.) Establishing the diagnosis is usually straightforward, either through a careful history or viral culture/DFA of an active lesion. Warning — some people with a history of “recurrent zoster” aren’t too thrilled to hear they have herpes instead, especially of the Type 2 variety, so caution when informing him/her of this diagnosis. All kinds of relationship turmoil can ensue.
  2. Post-herpetic neuralgia complicated by “neurodermatitis.” I put that last word in quotes, because that really isn’t the most common use of the term, but it truly fits. Here’s what happens — the patient with zoster has, as a manifestation of post-herpetic neuralgia, tingling and itching at the site. He/She then scratches and picks at it relentlessly, until the skin is red and bumpy — which is then mistaken for “recurrent zoster.” These itchy red bumps really look nothing like shingles, and of course are associated with no viral replication, but the location right at the site of prior shingles fools people.
  3. Wolf’s isotopic response. I’m lucky to have a brilliant dermatologist as a colleague; he clued me in to this oddly named entity, which is a fancy way of saying “a new skin disease at the site of an already healed, unrelated disease.” Turns out herpes zoster is the most common initial skin lesion, and then a whole host of other things can occur in that same site. Despite the name, it has nothing whatsoever to do with radioactivity, but sure will impress your friends if you mention it in casual conversation.

I’m sure this short list isn’t comprehensive, but you get the point. If you and the patient think it’s recurrent zoster happening over and over again, it almost certainly is something else, and the three entities listed above are a good place to start.

8 Responses to “Common Curbsides: The Patient with “Recurrent Zoster””

  1. Loretta S says:

    Assuming it is truly HSV the patient has, I am guessing you would *not* place the patient on chronic suppressive therapy, but would instead treat each outbreak individually. Or am I wrong about that? Happy New Year, Paul! Love your blog. It has taught me a lot.

    • Paul Sax says:

      Hi Loretta,

      The use of chronic suppressive therapy for HSV (not VZV) depends on the frequency and severity of outbreaks, as well as sometimes the person’s interest in taking treatment to reduce the risk of passing the virus to their sexual partner.

      In this case, the subsequent outbreaks were much milder than the first one (very commonly the case), so she elected not to take suppressive treatment.

      Paul
      p.s. happy new year to you!

  2. Patricia Tayao says:

    A 67 yrs old female with type 2 DM developed 3 papulo vesicular lesions in left mid upper abdomen with pain/tingling laterally and posteriorly 5-7 days after receiving
    zostavax.
    Do you treat this with antiviral medication and consider this as an infection or a breakthrough rash reaction to the vaccine? Do you tell them to remain off work till rashes are all healed and dried up?

    • Paul Sax says:

      Hi Patricia,
      A rash so soon after immunization is probably not related at all. I’d treat with antivirals. And in general, the rash is covered (assume it would be in the location you describe) and the patient is not immunocompromised, we do not consider patients with zoster to be highly contagious.
      Paul

  3. Thanks you, as a retired clinician now administrator I want to thank you for contributing to my post-practice education with this wonder pearl about Wolf’s Isotopic Response. The very creative video insured I would see at least one creative thing today.

  4. Hossain Jabbari says:

    Dear Paul,
    Thank you for talking about this interesting issue which really is more a “neglected issue” rather than a “curbside topic”!
    Is there any study to show that its really confirmed that “Herpes Zoster” have no recurrence? Any PCR followed by RFLP?
    As we know HZV and HSV are from the same family.HSV can cause recurrent lesions with some minor comorbidities like stress, fever and so on. Zona could happen with underlying morbidities like HIV, diabetes, and even without them. So why we should not think to HZV to have such a recurrent? Does RFLPs have rulled out this entity
    And, thank you for introducing this odd- looking wastebasket: Wolf’s isotopic response! Is then something like adenocarcinoma of lung which more commonly happens on scar tissues from Tuberculosis also a Wolf’s isotopic response?
    Hossain

  5. Jonathan Blum says:

    Regarding the previous comment, there are multiple studies of zoster showing that recurrences are rare, at least for several years. That includes the Shingles Prevention Study, as Paul mentioned, and others. One exception (by B Yawn and colleagues), which showed more than the expected low rate of recurrence, was sponsored by Merck. RFLP analysis is not needed, only standard diagnostic virology (DFA, culture, or PCR). In my practice, almost all cases of recurrent zoster are due to HSV.

    • Dear Jonathan, Thanks for your nice comment. As you mentioned zoster recurrence is rare (by available evidence), but at the same time, number of studies in this regard are not sufficient to show the total picture of the problem, I think. Then, “absence of evidence is not evidence of absence”! As you know there was a similar talk about Tuberculosis re-, or new- infection in already infected ones few years ago, but further studies showed that we could have 17-20% of re-infections in confirmed TB patients, although not by same strains, but they could happen!
      As you know HZV has at least 4 genotypes, and there are studies showing that both varicella re- infection and zoster recurrences could happen with different genotypes in previously infected people (http://cid.oxfordjournals.org/content/43/10/1301.full.pdf+html ).
      As you know again, DFA, culture and PCR are diagnostic methods, and not a method to differentiate between different genotypes. To do that, still RFLP and sequencing are the main methods.
      To sum up, I think although in most of the cases of suspected zoster recurrences, HSV, post herpetic neurodermatitis, Wolf’s isotopic response, and even bolus impetigo are the common diagnosed reasons, but virological studies in practice to rule out recurrence with the same or other genotypes are scarce, and we rule out them without sufficient studies with representative sample sizes.
      Hossain

HIV Information: Author Paul Sax, M.D.

Paul E. Sax, MD

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