Setting: office
CC: “My side hurts.”
VS: BP: 142/92 mm Hg; P: 102 beats/minute; T: 99.2°F; R: 18 breaths/minute
HPI: A 72-year-old man comes to your office with complaints of pain in the left side of his chest for the past 5 days. The pain is continuous and increasing in intensity. He comes now because he has developed a rash at the site where the pain is.
PMHX:
Benign prostatic hypertrophy
Chronic obstructive pulmonary disease (COPD)—mild
Former smoker—stopped 15 years ago
Medications:
Tiotropium regularly
Albuterol intermittently
Finasteride
Tamsulosin
Pain can elevate blood pressure (BP).
Single BP elevations with pain are meaningless.
PE:
General: uncomfortable from pain
Chest: vesicular rash in a stripe across the left side of the chest. Rash does not cross the midline. Vesicles are fluid filled. No crusting is visible.
Herpes zoster rash does not cross the midline.
Varicella-zoster virus (VZV) is stored in the dorsal root ganglia—one side only.
Which of the following is most important to do first for this patient?
a. Tzanck prep
b. Viral culture
c. Antiviral treatment
d. Varicella serology of blood
Answer c. Antiviral treatment
When there is a clear dermatomal distribution of herpes zoster or shingles, neither the Tzanck prep nor viral culture is necessary. Nothing else besides VZV gives a vesicular rash in a dermatomal distribution. When testing is needed, the viral culture of the skin is the most accurate test. Viral culture needs to be done on specific viral media. It will not grow on blood agar. The Tzanck smear can be useful in herpes infections, particularly VZV. VZV takes 10 to 14 days to grow, so although viral culture may be the most accurate test for herpes zoster, it is most often not clinically practical because it does not allow an answer in time to affect treatment.
Tzanck Smear
• Swab or smear of lesion
• Pathologic and cytologic test on a slide
• Like a Papanicolaou (Pap) smear of the cervix
• Multinucleated giant cells in positive test
• Cannot distinguish herpes zoster from herpes simplex
Herpes Virus Family
• Simplex 1 and 2
• VZV
• Cytomegalovirus (CMV)
• Epstein-Barr virus (EBV)
• Human herpes virus 6,7, 8
Initial Orders:
Give valacyclovir orally.
Keep vesicles covered.
Herpes Zoster = Shingles = Varicella Reactivation
Can varicella spread to others?
a. Never
b. Only adults who have not had shingles
c. Only persons who never had chicken pox or the vaccine
d. Children yes, adults no
Answer c. Only persons who never had chicken pox or the vaccine
It is possible for VZV that causes shingles reactivation to spread to others. It is highly unlikely if the shingles is only on one or two dermatomes, but it is possible. The patient should not be allowed near patients who are immunocompromised and have never had chicken pox or the vaccine.
• VZV can spread to nonimmune persons.
• VZV is spread by airborne transmission.
Valacyclovir = Acyclovir = Famciclovir Equal Efficacy
Steroids in Zoster
• Not clearly beneficial
Move the case forward to be sure that there is no spread to other dermatomes and that it does not disseminate. In addition, you want to be sure that there is crusting of the lesions, indicating that healing has occurred and that there is no possibility of transmission.
Interval History: “Lesions are crusting, but there is still some pain.”
PE:
No fever
Chest: crusting of vesicular lesions
Transmissibility stops when the lesions dry and crust.
What is the mechanism of valacyclovir?
a. Protein inhibition
b. Cell wall
c. Thymidine kinase
d. Reverse transcriptase
Answer c. Thymidine kinase
Acyclovir, famciclovir, and valacyclovir work by inhibition of thymidine kinase. Without an effective thymidine kinase, the genetic material of the herpes virus cannot reproduce. These agents are effective against herpes simplex and VZV. They are not effective against CMV.
What is the best postexposure prophylaxis for a pregnant woman exposed to shingles or chicken pox?
a. Varicella-zoster immune globulin (VZIG)
b. VZIG and varicella vaccine
c. Varicella vaccine
Answer a. Varicella-zoster immune globulin (VZIG)
VZIG offers some protection against acquiring new varicella infection. The persons most in need of postexposure prophylaxis are those who are pregnant and those who are immunocompromised, such as those undergoing chemotherapy and those using steroids. Pregnant women should not receive varicella vaccine because it is a live-attenuated vaccine. Live vaccines should be avoided in pregnancy because of concern that they might spread to the fetus.
Varicella vaccine is a live-attenuated virus.
Avoid in varicella vaccine immunocompromised or pregnant persons.
VZIG
• Immunoglobulin G (IgG)
• Intercepts VZV before it infects lymphocytes
Move the clock forward 1 to 2 weeks to see if postherpetic neuralgia has developed. Neither steroids nor tricyclic antidepressants (TCAs) will prevent the development of postherpetic neuralgia (PHN). If PHN does develop, acceptable treatments are pregabalin, gabapentin, or TCAs.
Interval History: “The patient’s lesions have fully healed, and there is no pain at this time.”
Which of the following is most likely to benefit the patient?
a. Chronic valacyclovir use
b. Zoster vaccine
c. Prednisone
Answer b. Zoster vaccine
Zoster vaccine in a person such as this is not to prevent the primary varicella infection. Zoster vaccine is to prevent the reactivation of shingles. It is the same type of vaccine, but at much higher dose. Zoster vaccine should be given to all persons at the age of 60 years to prevent shingles from occurring.
Five percent of people older than age 60 years get shingles.
Give zoster vaccine to those older than age 60 routinely!