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, 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, 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
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