It is more commonly known as shingles and is caused by the same agent responsible for chickenpox, the varicella-zoster virus.
It is called shingles, or shingles, the infectious disease triggered by the reactivation of the varicella-zoster virus, after the first contact of this viral agent with the body caused chickenpox.
All individuals who in the course of their lives have been affected by this exanthematous disease may, as a result, subsequently develop shingles. Let’s see together why and when this can happen, how to recognize the infection and how to deal with it.
A virus that returns
Varicella-zoster (also called herpes virus 3) is a virus of the herpes virus family, the same, to be clear, to which herpes simplex 1 (responsible for cold sores, also known as lip fever) and herpes simplex 2 (which causes genital herpes) belong.
These herpes viruses have a common feature: once they have triggered a first infection, even after healing they are not completely destroyed, but remain latent and inactive within the body. The viruses in question, in particular, lurk inside the sensory ganglia, structures of the nervous system that are located along the course of the dorsal roots that protrude from the spinal cord, in the spinal nerves and in some of the cranial nerves.
The duration of the latency period of these viruses is variable, also depending on the type of agent taken into consideration: if, for example, herpes simplex 1 tends to reactivate rather often and always determining a new recurrence of the first infection, varicella-zoster may not reactivate or do so, generally, only once in a lifetime, Even after many years from the first encounter with the body (in fact, reactivation more often concerns subjects over 50 years), triggering a pathology different from the first infection.
Chickenpox is the first manifestation
The varicella-zoster virus is transmitted only from man to man: transmission occurs in particular by direct contact with the liquid present in the bubbles that appear on the skin following infection. When the varicella-zoster virus first encounters the human body, it triggers chickenpox, one of the main contagious diseases of childhood.
After an incubation of about 2-3 weeks, the disease usually begins with fever, general malaise, headache, fatigue and a rash characterized by small pink papules itchy all over the body, which evolve into vesicles and then, in 4-5 days, dry out and leave small crusts. The outburst is formed in successive waves and lasts even for 10 days.
Symptoms are usually more noticeable and prolonged if the disease affects adolescents or adults. Chickenpox tends to resolve on its own, so the therapy is mostly symptomatic: paracetamol can be used for fever, possibly antihistamines against itching and, only in cases most at risk of complications, antiviral drugs can be prescribed.
Why the virus can reactivate
Although the body’s immune response is usually sufficient to block the disease, as we have already anticipated, the varicella-zoster virus is not completely eradicated by antibodies and takes refuge in the nerve ganglia until a possible reactivation.
It seems that what allows the virus to reactivate is a lowering of the immune defenses, for example in conjunction with periods of high stress, or following pharmacological therapies with immunosuppressive drugs (such as anti-rejection drugs that must be taken after an organ transplant), chemotherapy and radiotherapy , or in the presence of an immune system weakened by other conditions (for example in the case of HIV) or made more fragile by old age. Not surprisingly, as already mentioned, it seems that the reactivation of the varicella-zoster virus, as far as it is possible at all ages, occurs more frequently after the age of 50.
Symptoms of shingles
When the virus is reactivated, it can spread from one or more sensory ganglia, going up the nerve to the strip of skin (called dermatomere) innervated by these nerve fibers. Precisely in the affected skin area, burning, pain, itching and pangs are initially accused, quickly associated with the appearance of cluster skin lesions overlapping those caused by the virus during chickenpox, ie itchy bubbles full of liquid that then, usually within a few days, dry up and leave scabs destined to fall. The area is also particularly sensitive to stimuli, so even a slight touch can be annoying. These typical symptoms can also be associated with headache, fatigue and a feeling of general malaise.
This acute phase typically lasts two to four weeks. The vesicles tend to form for several days and the liquid they contain is highly infectious: by direct contact with the liquid a subject with herpes zoster can infect another person who has never had chickenpox, making him sick with chickenpox and not with shingles.
Shingles can affect any part of the body, generally only on one side, but mostly the chest, abdomen or limbs are affected.
Particularly serious are the reactivations involving specific nerve fibers. This can include, for example:
- an ophthalmic herpes zoster, when reactivation involves the branch of the trigeminal nerve that innervates the eye, thus affecting the eyeball and sometimes also the tip of the nose
- a herpes zoster oticus or auricle, when the part of the facial nerve that innervates the ear is affected.
As it is easy to understand, these forms can be dangerous because they put at risk, respectively, sight and hearing (zoster oticus, moreover, can also cause partial paralysis of the face, sometimes even permanent).
Shingles therapy
St. Anthony’s fire tends to resolve spontaneously, but there are medications that can help limit the duration and intensity of acute phase symptoms and reduce the risk of later complications.
Generally, antiviral drug therapy is used, but to be effective it must be started within 72 hours of the appearance of the rash.
Only in some cases, such as in the presence of an ophthalmic herpes zoster or oticus, the doctor may also prescribe corticosteroid medications to reduce inflammation. Food supplements (for example based on B vitamins or alpha-lipoic acid) can also be suggested with the aim of strengthening and protecting peripheral nerve fibers, limiting the damage produced by the virus.
A complication: post-herpetic neuralgia
After the acute phase, for some people a rather feared and debilitating complication can occur: post-herpetic neuralgia.
It is a neuropathic pain in the area affected by the zoster, a consequence of the damage that the virus has produced by replicating in the nerve fibers, which can last weeks, months or years and therefore become chronic.
This pain can be continuous or episodic, it can appear spontaneously or even after stimuli so mild as to be normally harmless. In addition, it can manifest itself in many ways, depending on the type of nerve fiber injured:
| Burning pain | Alteration of the finer fibers that transmit heat |
| Tingling | Lesion of the fibers that transmit tactile sensations |
| Stungent pain | Dysfunction of nerve fibers that transmit cold |
Shocks, pangs can also be felt and, if several fibers are damaged, all these manifestations can also be present at the same time. As you can guess, post-herpetic neuralgia can therefore be such as to seriously compromise the quality of life.According to existing specific guidelines, neuropathic pain is mainly treated pharmacologically. Common anti-inflammatory analgesics are essentially ineffective in treating this type of pain and are not considered appropriate. The first choice medicines are not painkillers in the strict sense, but belong to the category of antiepileptics and antidepressants: the former act by modulating the transmission of the pain signal along the nerve fibers, while the latter intervene on the perception of pain.
Since in postherpetic neuralgia the pain is localized in a restricted part of the body, the doctor may also prescribe local treatments, such as patches based on an anesthetic, lidocaine, to be put every 12 hours (usually overnight), but with a duration of effect of 24 hours. There are, but are less used, also patches that release capsaicin (the substance that gives the spicy taste to chili) that act by blocking painful transmission for a few months.
In the case of neuropathic pain, opioid drugs are considered, finally, of second choice, that is, reserved for cases in which the others do not give sufficient results.
Prevent with vaccination
To prevent varicella-zoster infection, you can focus on the vaccine, available both for those who have never contracted the virus, to avoid chickenpox, and for those who have already had this infection, in order to avoid the risk that, due to a reactivation of the virus, herpes zoster and, above all, post-herpetic neuralgia occur.
According to the new National Vaccination Prevention Plan 2017-2019 and the vaccine decree, vaccination against chickenpox is now mandatory (and free) for all those born from 2017: a first dose is expected in the second year of life and the second at six years.
The new vaccination plan has also made the herpes zoster vaccine free for the over65s: in these cases only one dose is sufficient.
Joycelyn Elders is the author and creator of EmpowerEssence, a health and wellness blog. Elders is a respected public health advocate and pediatrician dedicated to promoting general health and well-being.
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