From the Guidelines
Herpes zoster is most contagious from 1-2 days before the rash appears until all lesions are crusted, typically 4-7 days after rash onset. This contagious period is critical because direct contact with the fluid from the blisters can spread the varicella-zoster virus to individuals who have never had chickenpox or the chickenpox vaccine 1. The key factors to consider in the spreading period of herpes zoster include:
- The average incubation period of 14–16 days after exposure to the rash, with a range of 10–21 days 1
- The contagious period, which starts 1-2 days before the rash appears and lasts until all lesions are crusted over, typically 4-7 days after rash onset 1
- The importance of preventing transmission by covering the rash completely, avoiding touching or scratching the rash, washing hands frequently, and avoiding contact with high-risk individuals until the blisters have fully crusted over
- The fact that the virus cannot be spread through coughing or sneezing, and a person with shingles cannot give someone else shingles directly, but can potentially give someone chickenpox if that person is susceptible 1
In terms of morbidity, mortality, and quality of life, it is essential to take precautions to prevent the transmission of herpes zoster, especially to high-risk individuals such as pregnant women, newborns, and immunocompromised people. By understanding the contagious period and taking preventive measures, individuals can reduce the risk of transmission and minimize the impact of herpes zoster on their quality of life. According to the study, varicella vaccine coverage has led to dramatic declines in varicella incidence, hospitalizations, and deaths, highlighting the importance of vaccination in preventing the spread of the virus 1.
From the Research
Spreading Period in Herpes Zoster
- The spreading period of herpes zoster is not directly mentioned in the provided studies, but the duration of the disease and its symptoms can be inferred from the studies.
- According to 2, the blister stopping time, pain relief time, and scabbing time can be shortened with the use of antiviral agents such as acyclovir, valaciclovir, and famciclovir.
- The study 3 mentions that oral antiviral therapy, when initiated within 72 hours, can reduce the duration and intensity of zoster-associated pain and provide more rapid skin lesion healing.
- The review 4 found that valaciclovir and famciclovir can significantly reduce the risk of pain associated with herpes zoster, with the largest risk reduction seen at 21-30 days.
- The comparative study 5 found that valacyclovir can accelerate the resolution of zoster-associated pain and provide a greater resolution of pain compared to famciclovir.
- The clinical trial 6 found that famciclovir and acyclovir have similar efficacy in treating herpes zoster, with a similar time to full crusting of lesions and a high rate of cure.
Duration of Herpes Zoster Symptoms
- The duration of herpes zoster symptoms can vary, but the studies suggest that antiviral therapy can shorten the duration of symptoms such as pain, blistering, and scabbing.
- The study 2 found that the blister stopping time can be shortened by 1.29 days with the use of 800 mg acyclovir, and the scabbing time can be shortened by 2.42 days.
- The review 4 found that valaciclovir and famciclovir can reduce the risk of pain associated with herpes zoster, with the largest risk reduction seen at 21-30 days.
- The comparative study 5 found that valacyclovir can accelerate the resolution of zoster-associated pain, with a significant decrease in pain scores at day 29.