Skills Station: Postherpetic Neuralgia

EMS providers respond to a variety of calls--some that require immediate intervention and other situations that are less acute. During your EMS career there is the possibility that you will respond to incidents that require you to consider numerous causes because the patient's current condition/illness/injury may not be immediately obvious. This could be the case with postherpetic neuralgia.

Postherpetic neuralgia (PHN) is a painful condition involving the nerve fibers and skin and is a complication of shingles, or the herpes zoster, which results from chickenpox. The pain associated with postherpetic neuralgia tends to be isolated to the location on the body where the shingles outbreak occurred.^1,2

When an individual becomes infected with chickenpox, some of the virus may remain dormant in nerve cells. At an unknown time in the future, the virus may be reactivated and result in shingles, which is a painful rash. Postherpetic neuralgia can be seen in more than 50% of shingles cases. ¹

Chickenpox Overview

Chickenpox, or varicella, is an infectious disease that is caused by the varicella-zoster virus and, in most cases, is self-resolving. It is spread among humans through airway fluids (coughing or sneezing), as well as through sharing food or drinks. Non-infected individuals who are near an infected individual are at risk of becoming infected. This includes family members and classmates. Children under age 10 are the most likely to become infected.

The development or incubation period for chickenpox is 14-16 days, or 2-3 weeks. The initial signs of the disease may be a fever, headache and/or sore throat followed by a rash. It is also possible for the patient not to exhibit any symptoms except the rash. Infected individuals are considered to be contagious for 2-5 days before the onset of skin lesions and 6 days after the last series of rashes have appeared. Treatment is primarily supportive, including oatmeal baths to reduce itching. ³

Shingles Overview

Shingles, also referred to as herpes zoster, is a viral infection that is caused by the reactivation of the chickenpox virus. When the varicella-zoster virus is re-activated, the individual develops shingles instead of chickenpox. Common symptoms include pain and a rash on one side of the body that may appear as a band of blisters that wraps from the middle of the patient's back around one side of the chest to the breastbone. Shingles are more likely to occur among older adults, as well individuals with a weak immune system. ^4-6

Postherpetic Neuralgia

Neuralgia is the pain that occurs when a nerve becomes irritated or inflamed. With neuralgia, the pain can spread throughout the body along neural pathways. The pain may be brief or chronic and can range from mild to extreme. Postherpetic neuralgia occurs after an individual is infected with herpes zoster. While specific timelines vary, pain or discomfort that continue for 1 to 4 months after resolution of the herpes zoster rash is considered postherpetic neuralgia. ^7,8

In postherpetic neuralgia, the discomfort or pain may be described as a continuous burning sensation, sharp and stabbing, or deep and aching in nature. The pain can also be extreme. Individuals with postherpetic neuralgia may be sensitive to light touch, even of clothing or a gentle breeze. Postherpetic neuralgia may also cause itchy feelings and/or numbness. Depending upon the nerves involved, the infected individual may experience muscle weakness and/or paralysis. ^7,8

Numerous factors can influence the likelihood of a patient developing postherpetic neuralgia. Examples include individuals who are older, female, and who have symptoms (numbness, tingling, itching, pain) before the rash develops. Additional factors include severity of pain during the illness and severity of the rash. ⁸

The individual with postherpetic neuralgia may experience a wide range of life-impacting effects. For example, he or she may experience chronic fatigue, anorexia, weight loss, reduced physical activity level, insomnia, difficulty concentrating, depression and suicidal ideations. In addition, they may experience challenges with daily activities such as dressing, bathing, eating, traveling and cooking. ^2,7,8

Prehospital Assessment

Prehospital care should begin with an assessment and management of the patient's ABCs. A secondary assessment should also be performed. The hands-on assessment may require you to proceed with gentle finesse. Because the patient may be experiencing discomfort and/or pain, any physical touch may exacerbate his discomfort level. In these situations, it is helpful to clearly communicate and explain the steps and procedures involved. This may include letting the patient know when and where you may be touching him, even when performing basic procedures like applying a blood pressure cuff.

During the assessment, observe the patient's overall condition. Be aware of any dermal abnormalities that might be present, such as a rash or bruising. Record vital signs, including temperature and the presence of orthostatic vital sign change.

Prehospital Treatment

The prehospital treatment will vary depending on the situation, including the patient's symptoms, local protocols and proximity to a hospital. In some cases, treatment may be predominantly supportive, while other situations may require more provider intervention. The use of medications, such as analgesia, will also be guided by factors like the patient's condition and local protocols. Providers should recognize that medical equipment that contacts the patient's skin, such as a blood pressure cuff, might exacerbate his discomfort and contribute to increasing the patient’s anxiety level, including increased heart rate, blood pressure and respiratory rate.

Conclusion

The patient experiencing postherpetic neuralgia may have a variety of signs and symptoms, including pain and discomfort. While calls like these are not always acute, providers can still provide supportive care while recognizing that the patient is experiencing a chronic and potentially challenging situation.

References

1. Centers for Disease Control and Prevention. Vaccines and Preventable Diseases: Herpes Zoster Disease-Q&As for Providers (Shingles).

2. Morbidity and Mortality Weekly Report, Centers for Disease Control and Prevention. Prevention of Herpes Zoster Recommendations of the Advisory Committee on Immunization Practices (ACIP).

3. WebMD. Chickenpox (Varicella)-Topic Overview.

4.WebMD. Shingles-Shingles Health Center: Topic Overview.

5 Logical Images, Skinsight Research. Shingles (Zoster) Information for Adults.

6 WebMD. Understanding Postherpetic Neuralgia-The Basics.

7. Beth Israel Medical Center. Healing Chronic Pain. Integrative Pain Medicine-Post-Herpetic Neuralgia.

8. WebMD. Shingles Health Center. Understanding Postherpetic Neuralgia-The Basics.

Paul Murphy, MSHA, MA, has administrative and clinical experience in healthcare organizations.