Herpes Simplex Virus and Shingles

00:01 Now that we've wrapped up this case of codylomata acuminata, we do need to further discuss the various manifestations of herpes simplex virus which has so many different manifestations on the skin.

00:12 We alluded to genital herpes in this case, but HSV causes a lot more trouble than just the occasional herpes.

00:19 Let's take a look at HSV1 first and then we'll take a look at HSV2.

00:24 So as you can see right off the bat, the prevalence of HSV1 is 66% worldwide, so it's a wildly endemic viral infection.

00:34 And as I mentioned, there are multiple skin and systemic manifestations and we'll go through some of them today.

00:40 It's transmitted via mucosal secretions and oftentimes, if you have an active herpetic lesion, as you might imagine, it's much more likely to be transmitted cause the virus is living in that lesion and is being secreted.

00:53 We'll talk more about the difference between a primary HSV infection versus secondary reactivation infection.

01:01 So here we can talk about the difference between the primary and secondary infection with HSV1.

01:06 Primary infection is the initial infection.

01:09 After inoculation, there's about a 2 to 12-day period of incubation before you can develop gingivostomatitis.

01:16 A milder version is shown here but essentially, gingival stomatitis can just involve a few ulcers on the back of the hard palate or it can present much more floridly with significant mucosal inflammation, edema, ulceration and hemorrhagic crusts on the lips and on the buccal mucosa.

01:33 This presentation is oftentimes accompanied by lymphadenopathy, fever, malaise, headaches and severe pharyngitis with odynophagia, which as you might imagine, might impair a patient's ability to swallow, particularly since this can occur in children.

01:48 In contrast, a seconday HSV1 presentation or reactivation occurs in about 20 to 40% of people who have previously been infected and it could be months or years before somebody has a secondary reactivation of HSV1.

02:04 These lesions are triggered by different types of exposures.

02:08 It could be excess sunlight, it could be a fever due to some other infection or just psychological stress, trauma to the area like if you bite your cheek or your tongue and in folks who are immunocompromised, they're much more likely to have these reactivations especially as you get older or if you have any other types of infections going on that could compromise your immune system.

02:28 The most classic lesion is shown here with this herpes labialis lesion at the vermilion border.

02:34 Remember the vermilion border is the junction between normal skin and the beginnings of the mucosa of the lip.

02:41 Interestingly enough, these lesions are often preceeded by pain, paresthesias, maybe even just some itchiness that the patient will experience a few days before the appearance of the vesicles so they have a little bit of a warning that these are coming.

02:55 Rarely, patients will have some systemic symptoms but typically it's not nearly as acute a presentation as someone having a primary lesion.

03:05 Okay, so here's a list of all of the HSV1 manifestations even though this list is not even fully comprehensive.

03:13 We've already talked about herpetic gingivostomatitis.

03:16 We've talked about herpes labialis and cold sores.

03:19 The next stop we'll talk about herpetic whitlow, this is a old term but it basically refers to an HSV1 infection of a finger or around the fingernail.

03:29 As you might imagine, these are relatively common in kids who are constantly getting cuts in the skin and essentially HSV1 just penetrates the dermis and causes a local infection.

03:39 Next stop is genital herpes which we've talked about previously.

03:43 Just a reminder that while HSV2 is the most likely cause of genital herpes, HSV1 can also cause those lesions.

03:52 Now, we already discussed erythema multiforme earlier on this section but I'll just remind you, that you wouldn't find HSV1 itself in any of the lesions of erythema multiforme.

04:02 Remember, it represents an immune-mediated hypersensitivity reaction to the virus, rather than a manifestation of the virus itself in the skin.

04:10 In contrast, those first five lesions on the left side of our screen would actually yield HSV1 if you were to biospy them.

04:19 Next stop, herpetic keratitis.

04:21 This is actually an ophthamologic emergency involving HSV1 infection of the cornea itself and you could see this with flourescene on the slit lamp exam as well.

04:32 Next stop are a variety of neurologic manifestations of HSV.

04:36 This can include herpes encephalitis, aseptic meningitis and Bell's palsy.

04:41 That's the one that's shown here with 7th cranial nerve palsy.

04:45 Having spoken about HSV1, let's shift the gears and start talking about HSV2.

04:50 The prevalence of HSV2 in high-income countries is about 16% and this also have a primary infection presentation and a secondary reactivation presentation.

05:00 First up, primary infection after inoculation, patients will experience bilateral genital ulcers with lymphadenopathy, fevers, myalgias and potentially, if the lesions exist around the urethral os, you may have some dysuria as well.

05:15 In contrast, after that spontaneously resolves, a number of patients will present with reactivation or secondary infection.

05:21 This is characterized by small erosions, maybe some vesicles on an erythematous base and they're unlikely to have systemic symptoms at the time of presentation.

05:30 Diagnosis is fairly straightforward, there's a number of different ways to do it but the most sensitive and specific approach is gonna be with PCR testing.

05:38 Direct flourescent antibody testing is also useful though it doesn't quite have the same sensitivity and specificity and a viral culture can be done but the sensitivity is not very high and of course it can take some time to obtain.

05:49 Serology, I should just point out, is effectively useless because the prevalence of HSV1 and HSV2 is so high, it's not gonna tell you if there's seropositivity explains their current presentation.

06:00 Simply unroof a vesicle, swab the lesion and send it off to the lab.

06:06 To treat these lesions acutely as long as you catch it early, you can use valcyclovir or acyclovir but if it's been several days into the lesion, it's probably just gonna resolve on its own.

06:16 Subsequently, if a person has recurrences, multiple recurrences overtime, patients oftentimes take prophylactic valcyclovir or acyclovir to prevent future infections.

06:25 Alright, so we've covered HPV, HSV, measles, molluscum contagiosum, what a lecture.

06:32 We'd be remiss however, if we didn't discover quickly this rash.

06:37 You've gotta be able to recognize this one.

06:39 Painful, unilateral, vesicular rash, common in the elderly and immunocompromised.

06:45 You guessed it, it's shingles caused by VZV.

06:48 This is a painful, dermatomal vesicular rash, common in the elderly and immunocompromised as I said.

06:56 While it's caused by reactivation of latent varicella zoster virus, it can be complicated by some pretty severe infections.

07:04 Involvement of the V5 ophthalmic branch, which can cause potentially vision-threatening inflammation, but more commonly, about 10-15% of patients who get shingles will develop postherpetic neuralgia.

07:15 This is a painful neuropathy that persists for more than 90 days after the dermatologic inflammation has long since resolved.

07:22 This condition can be debilitating for patients and requires the use of a variety of the gabapentinoid kind of medications to cool it down.

07:31 Otherwise, when it's initially presenting, as long as you catch it early, you can treat sometimes with steroids.

07:36 You can use antivirals but once it's passed the initial vesicular stage and it's starting to crust over, those medications are less likely to be effective.

07:45 And of course, we now have vaccines to try and prevent this infection or reactivation with things like zostavax.

07:51 which patients are recommended to get once they have gotten above a certain age.