Shingles

) is a resurgence of chickenpox he had as a child. Infection in adulthood derives, in fact, from the reactivation of the varicella-zoster virus from its latent state in a dorsal root ganglion. The most characteristic sign of the disease is a "painful rash, the onset of which is preceded by a sensation of local tingling or numbness. A strip of red dots then appears, which then evolves into clusters of vesicles on an erythematous, fluid-filled base, similar to chickenpox lesions. The pain is very intense and continuous, associated with superficial itching and burning. The fire of Sant "Antonio is located in a very specific area: it manifests itself more frequently in one side of the chest or back at the waist height; the distribution of the vesicular eruption always corresponds to that of the sensory nerves affected by the virus. More rarely, lesions appear on one side of the face, around the eye and forehead, inside the mouth, on an arm or leg. Sometimes, herpes zoster also presents with fever, chills, headache, and general malaise.

The symptoms that characterize herpes zoster lend themselves to a fairly unambiguous interpretation and the visual inspection of the affected area by the doctor is generally sufficient. In case of suspicious signs it is still possible to resort to some laboratory analyzes. The most common test is a blood test for IgM specifically related to the presence of the varicella-zoster virus (VZV). In other cases, however, it is possible to carry out the determination of the viral particles by PCR (polymerase chain reaction for the research of the DNA of the virus).

it can occur through direct contact with the fluid contained in the vesicular lesions, in which the varicella-zoster virus is present and active. The subject, on the other hand, is not infectious before the rash appears and after the evolution of the vesicles into dry crusts.

To avoid the risk of transmitting the varicella-zoster virus to other people, the patient should avoid touching or scratching the blisters, wash their hands often and keep the rash covered. In addition, the person with Herpes zoster should not share personal items. (e.g. towels), going to the pool or playing contact sports, such as rugby.

During the active phase of the fire of Sant "Antonio, then, it is particularly important to prevent the spread of the infection to pregnant women, newborns and immunosuppressed people (eg patients undergoing therapy with immunosuppressive drugs or undergoing chemotherapy and transplantation" organ).

(VZV), in fact, has the ability to remain latent in the ganglia of the spinal nerves, invaded during the course of the primary infection, without giving symptoms and, in 10-20% of cases, it can reactivate, causing the so-called "Sant's fire" Antonio "(Herpes zoster).

The subject, therefore, will not re-present chickenpox, but a local skin manifestation characterized by clusters of vesicles that cause burning pain along the course of the nerve, where the virus has stationed. The events triggering the reactivation are not clear, but it is known that the phenomenon is more frequent with advancing age and in patients with deficient immune defenses.

A person suffering from Herpes zoster can transmit chickenpox (but not St. Anthony's fire) to an "other person who has never contracted it (or who has not been vaccinated). In order for the infection to occur, however, it is direct contact with the vesicular lesions (in which the chickenpox virus is present) is necessary. During the fire of Sant Antonio, in fact, the viral agent does not usually affect the lungs and cannot spread by air (unlike what happens during chickenpox).

human beings, they undergo a condition of quiescence. In this state, the organism does not replicate and do not generate enough viral-derived peptides to signal their presence to cytotoxic T cells.

As a rule, in fact, to neutralize an already established viral infection, the cytotoxic T lymphocytes kill the infected cells, but it is necessary that some of the peptides presented by the class I MHC expressed on the surface of the infected cells are of viral origin. This condition is easily reached in the course of infections caused by rapidly replicating viruses, as happens, for example, during the flu (neutralized by the combined action of lymphocytes and antibodies).

Herpes virus strategy leads to the development of a latency. In some circumstances, especially when the immune defenses are lowered, the virus will reactivate causing an episode of disease. Once the replication phase is over, the virus finally tends to go back to lock itself up in the nerve ganglia, thus maintaining the cycle that underlies the persistence of the infection.

, erysipelas (acute bacterial skin infection), ergotism (toxic foodborne disease) - they prayed to him.

caused by Herpes zoster, a transdermal patch is also available in Italy. Being localized and superficial, in fact, herpetic infection neuralgia can be tackled with topical treatment.

The medicated plaster, to be applied directly on the painful part, contains 5% lidocaine, a local anesthetic able to provide good symptomatic relief. The tolerability profile is good, even in prolonged use; side effects are minimal. The lidocaine patch is applied for 12 hours, but offers relief for a full day.

, with the possibility of reactivating in adulthood, especially in periods in which the immune defenses are lowered. When it awakens from latency, the varicella-zoster virus multiplies and travels up the path of a peripheral nerve to the skin, causing neuropathic pain and vesicular lesions. The fire of Sant "Antonio affects one in four people in the course of their life: the risk of developing it increases with age, especially affecting the" over 50 ".

According to the results of a British study presented in "Neurology" by researchers from University College London, "Herpes zoster infection in young adults can increase the risk of a cardiovascular event ("Herpes zoster as a risk factor for stroke and TIA"). The results of this research particularly support that, in people under the age of 40, the fire of Sant" Antonio increases the risk of stroke by 75% and heart attack by 50%. They are also 2.4 times more likely to have a transient ischemic attack (TIA). At the conclusion of their study, the authors stress the importance of controlling risk factors for stroke and heart attack - such as smoking, hypertension, obesity and high cholesterol - in patients with herpetic infection.

According to another study conducted by British researchers from the London School of Hygiene & Tropical Medicine and published in "Clinical Infectious Diseases", the risk of stroke would increase significantly immediately after the onset of the first symptoms of Herpes zoster ("Risk of Stroke Following Herpes Zoster: A Self-Controlled Case-Series Study"). The research team found that the risk of stroke was 63% higher in the first 4 weeks after herpes zoster reactivation (compared to patients' baseline risk) and slowly decreased over the next 6 months. study, however, antiviral drugs against Herpes seemed to provide a certain degree of protection: in patients undergoing therapy, the risk of stroke was lower than in untreated subjects.