Herpes zoster (HZ; also known as shingles) is a condition caused by a reactivation of a latent varicella-zoster virus (VZV) infection previously acquired as chickenpox (i.e., primary varicella infection). During chickenpox, VZV travels from the skin to the cranial nerves and dorsal root ganglion cells, where it remains in a dormant state. When reactivated, VZV travels along nerve pathways to the skin, causing lesions, inflaming the ganglia, and destroying nerve endings. (For more information on chickenpox and VZV, see Quick Lesson About … Chickenpox (Varicella); Quick Lesson About … Herpes Zoster (Shingles): an Overview; and Quick Lesson About … Varicella-Zoster Virus: an Overview)(1,2,4)
A person must have previously had chickenpox in order to develop HZ
HZ is not contagious unless a person has contact with the fluid in HZ lesions; this is because VZV does not usually spread to the lungs during HZ, so the virus is not shed into the air
Exposure to the fluid in HZ lesions can cause chickenpox (not HZ itself, which only results from endogenous reactivation of dormant VZV) in persons who have not had the disease, and it is recommended that pregnant women avoid exposure to persons with HZ lesions
The initial symptoms of HZ are usually unilateral pain, tingling, numbness, and/or burning. Any of these symptoms can be severe and are usually present for 2−3 days before the rash appears. Next, the skin erupts with red patches, which develop into small, fluid-filled blisters; the blisters form a band that typically wraps unilaterally around the trunk, chest, and/or abdomen following a dermatomal distribution. Although less common, blisters can also erupt on the face and ears, around the eyes and mouth, and on the genitals. Other symptoms include abdominal pain, fever, chills, achiness, headache, and fatigue(1,4)
The blisters break, forming small ulcers that begin to dry, and crusts form over a period of about 7−10 days; itching is common during this phase. When crusts form, the condition is no longer contagious and lesions heal within 3−5 weeks
The most common complication of HZ is postherpetic neuralgia (PHN; i.e., a potentially longer-term condition that develops after acute HZ, in which damaged nerves in the skin cause pain, which can be severe)
Other complications of HZ include encephalitis (i.e., inflammation of the brain), skin infections, balance and hearing impairment, and facial paralysis
HZ during pregnancy has become a rare occurrence in countries with high rates of immunization where chickenpox is also rare; it occurs in women who have impaired immunity (e.g., human immunodeficiency virus [HIV] infection/acquired immunodeficiency syndrome [AIDS], chronic lung disease, taking immunosuppressant medications). The incidence of HZ during pregnancy is unknown(2,3,4,5)
In contrast to varicella infection during pregnancy, which may result in intrauterine infection, congenital varicella syndrome (CVS), and neonatal varicella, there is no evidence of CVS or other complications associated with HZ during pregnancy(3)
In countries with a high prevalence of HIV infection, HZ during pregnancy has been used as an indicator of maternal HIV infection(5)
Pregnant women who have not had chickenpox—or who have not received the vaccine that immunizes against chickenpox—who are exposed to VZV (e.g., by living in the same household with a person who has active chickenpox or HZ; by face-to-face contact for at least 5 minutes with a person who has chickenpox or uncovered HZ lesions) should be given varicella-zoster immunoglobulin(2,4)
The pregnant woman should receive varicella−zoster immunoglobulin within 96 hours after exposure(2)
Oral acyclovir is recommended as prophylaxis for pregnant women who have either never had chickenpox or were not vaccinated against chickenpox, are seronegative for antibodies against VZV, who have had significant exposure to VZV, and/or who did not receive varicella−zoster immunoglobulin within 72–96 hours after exposure(2)
If a pregnant woman develops symptoms of HZ between 5 days before and 2 days after childbirth, the newborn has a greater chance of developing either neonatal chickenpox or pediatric HZ and should receive varicella-zoster immunoglobulin at birth(2)
Immunocompromised pregnant women are at increased risk for developing HZ
Oral acyclovir is recommended as prophylaxis for pregnant women with underlying risk factors (e.g., impaired immunity) who have significant exposure to chickenpox(2)
Antiviral drugs used to treat HZ are most effective if given within 72 hours of the first signs of the HZ rash in a pregnant woman(1,4)
Acyclovir is an antiviral agent that significantly reduces HZ symptoms
Valacyclovir and famciclovir are newer drugs that have superior oral bioavailability compared to acyclovir, require less frequent dosing with similar efficacy, but have been studied less than acyclovir
Acyclovir, valacyclovir, and famciclovir are pregnancy Category B drugs: the United States Food and Drug Administration (FDA) considers them safe for use during pregnancy because animal studies failed to demonstrate negative effects on the fetus
A Category B drug can be given to a pregnant woman if her clinician believes that its benefits outweigh any possible risks to the fetus/child
However, Category B drugs have not been studied in pregnant women, and animals do not always respond to drugs in the same ways as humans
Other medications commonly given for pain to patients with HZ (e.g., topical analgesics, antidepressants, opiates, anticonvulsants) may not be recommended for pregnant women.(1) (For details about pharmacotherapy to treat pain in HZ, see other topics in the Evidence-Based Care Sheet series on HZ)
Immunization with live attenuated virus vaccine, which is recommended to prevent HZ in older adults, is contraindicated for pregnant women and women of childbearing age(1)
The varicella (i.e., chickenpox) vaccine, given as a routine childhood immunization to prevent chickenpox, is recommended for adults who have never had chickenpox. However, varicella vaccine should not be used during pregnancy and should be administered at least 3 months prior to pregnancy because of risks to the fetus(1,4)
What We Can Do
Become knowledgeable about HZ during pregnancy so you can accurately assess your patients’ personal characteristics and health education needs; share this information with your colleagues
Follow facility infection control protocols for standard precautions; maintain standard precautions for when treating all patients with HZ
Staff who are susceptible to VZV should not care for patients with HZ
Visitors should use contact isolation
Monitor HZ treatment efficacy and for adverse effects of treatment; monitor vital signs (including fetal monitoring for hypoxemia and heart rate, as appropriate), intake and output, weight, and neurologic, respiratory, nutritional, and mental status
Educate patients that the varicella vaccine helps prevent chickenpox in adulthood and reduces the incidence of HZ during pregnancy; the vaccination is given at least 3 months prior to pregnancy if natural immunity is not present. Vaccinate patients who have not had chickenpox in the past, as prescribed and appropriate
Provide pregnant patients with HZ written information on HZ—including treatment risks and benefits and potential complications—and emphasize the importance of continued medical surveillance and seeking immediate medical attention for adverse drug effects or new or worsening signs and symptoms
Advise anyone with HZ to avoid contact with pregnant women
Request referral for patient with HZ to a pain specialist, as appropriate, to manage medications and their potential adverse effects during pregnancy; some pain medications (e.g., opiates) may be indicated for severe pain and are safe during pregnancy
Request that the clinician prescribe a prophylactic stool softener and/or laxative for constipation in pregnant patients with HZ, if opiates have been prescribed
Provide emotional support to pregnant patients with HZ; request referral to a mental health clinician for counseling on coping strategies, as appropriate
Request referral to a social worker for identification of local resources for educational programs or in-home services
Follow facility protocols for infection control and for mandated reporting of infectious disease
Note
Recent review of the literature has found no updated research evidence on this topic since previous publication on April 18, 2014