Herpes simplex viruses (HSV-1 and HSV-2) are double-stranded DNA viruses that cause numerous types of infections in humans. Apart from primary infections (when the individual is exposed to the virus for the first time), their recurrent ability to cause infections is possible because they establish a life-long latency in neuronal cells after their acquisition through direct contact with previously infected individuals [1]. Due to the loss of maternal antibodies, the initial infection by HSV-1 occurs in early childhood, either by direct contact with saliva and other secretions, whereas HSV-2 is principally transmitted through sexual intercourse [1] [2] [3]. It is estimated that antibodies to HSV-1 are present in up to 80% of adults, illustrating that many patients go through the initial encounter with HSV asymptomatically, while approximately 14% of adults have been exposed to HSV-2 and develop specific antibodies [1]. In the literature, the following clinical entities have been described [1] [2] [3] [4] [5] [6] [7]:

• Mucocutaneous infections - Acute herpetic gingivostomatitis and herpetic pharyngitis are two of the most common forms of primary HSV-1 infection, in which constitutional symptoms, irritability, and cervical lymphadenopathy appear and last up to 2 weeks, and are seen in the pediatric population [7]. Typical vesicular ulcerative lesions, the hallmark of herpes simplex infection, appear in the oral, gingival, labial, or buccal mucosa, and the surrounding skin [2] [7]. Herpes labialis (cold sores), on the other hand, denotes HSV-1 infection in adults as a result of its reactivation from a latent state in the proximal neuronal cells. Herpetic keratitis (infection of the eye presenting with a sudden onset of pain, conjunctivitis, and visual deficits), Herpetic whitlow (an infection of the finger), and Herpes gladiatorum (infection of the skin) are other less common forms [2] [3] [7]. On the other hand, genital herpes, predominantly caused by HSV-2 (although an increasing number of reports show an almost equal prevalence of HSV-1 and HSV-2 as causative agents), manifests with fever, myalgias, and a range of genital symptoms (vaginal/urethral discharge, dysuria, inguinal lymphadenopathy and pain) [1] [5]. Symptoms last for about 10-12 days in the setting of a primary infection, whereas recurrent forms usually have a milder clinical course [1] [5].
• Infections of the central nervous system (CNS) - Two main entities in this group are meningitis, principally occurring as a complication of genital HSV-2 infection, and encephalitis, with preexisting mucocutaneous HSV-1 infections being the probable cause of dissemination to the CNS [3]. The sudden onset of fever, neurological deficits, and altered consciousness must include herpes encephalitis in the differential diagnosis, as much higher mortality rates are seen if the diagnosis is delayed.
• Disseminated and systemic infections - The immunocompromised population (individuals suffering from malignant diseases, acquired immunodeficiency syndrome, or AIDS, prolonged corticosteroid therapy, etc) are at a particular risk for infections of the esophagus, lungs, the liver, and the CNS [3] [4] [7].
• Neonatal infection - Life-threatening herpes simplex infection in the neonatal period is usually acquired during delivery or postnatal contact with individuals who are shedding the virus. The neonate can develop any of the above-mentioned entities, particularly mucocutaneous and CNS forms [2] [6] [7].

The diagnosis of a herpes simplex infection starts with a meticulous patient history and a thorough physical examination that will identify the course of symptoms and the appearance of typical skin lesions, respectively. Physicians should carefully examine the skin and establish clinical suspicion based on the obtained signs and order a targeted laboratory investigation to confirm HSV as the underlying cause. In children, serology testing may be useful if a primary infection is suspected, as enzyme-linked immunosorbent assay (ELISA) can distinguish between antibody classes and confirm a high titer of immunoglobulin M (IgM) antibodies in serum [1] [2] [3]. Conversely, titers of IgG are not indicative of a recent or recurrent infection, which is why more advanced methods are necessary for adults. Detection of viral genetic material in serum, cerebrospinal fluid (in the setting of a CNS infection) or from biopsy samples through a polymerase chain reaction (PCR) testing are the methods of choice [1] [5] [6] [7]. Additionally, direct microscopic examination of the obtained biopsy samples is an equally effective method, and the Tzanck smear will show multinucleated giant cells and inclusion bodies in the nucleus, known as Cowdry type A acidophilic intranuclear inclusion bodies [2] [3] [7]. If frequent recurrences are observed, or if a disseminated infection is confirmed, the role of patient history is pivotal in assessing preexisting risk factors or underlying diseases, and a diagnosis of HIV infection must be excluded through appropriate serological testing.

While there is no cure for herpes simplex infection, antiviral medications can help manage symptoms and reduce the frequency of outbreaks. Common antiviral drugs include acyclovir, valacyclovir, and famciclovir. These medications can be taken during an outbreak to speed up healing or as suppressive therapy to prevent future episodes. Pain relief can be achieved with over-the-counter pain relievers and topical anesthetics. It's important for patients to follow their healthcare provider's recommendations for treatment.

Herpes simplex infection is a lifelong condition, but the frequency and severity of outbreaks tend to decrease over time. With proper management, individuals can lead normal, healthy lives. Antiviral therapy can significantly reduce the risk of transmission to others and help control symptoms. Emotional and psychological support may also be beneficial, as the diagnosis can impact mental well-being.

Herpes simplex infection is caused by the herpes simplex virus, which belongs to the Herpesviridae family. HSV-1 is primarily transmitted through oral contact, such as kissing or sharing utensils, while HSV-2 is mainly spread through sexual contact. The virus enters the body through mucous membranes or breaks in the skin and establishes latency in nerve cells, where it can reactivate and cause recurrent infections.

Herpes simplex infection is widespread globally, affecting millions of people. HSV-1 is more common than HSV-2, with a higher prevalence in developing countries. According to the World Health Organization, an estimated 67% of the global population under 50 years old has HSV-1, while 11% have HSV-2. The infection is more prevalent in women than men, and the risk increases with age and sexual activity.

Once the herpes simplex virus enters the body, it travels along nerve pathways to nerve ganglia, where it remains dormant. During periods of stress, illness, or immune suppression, the virus can reactivate, leading to recurrent outbreaks. The immune system plays a crucial role in controlling the virus, but it cannot completely eliminate it from the body. The virus's ability to establish latency and reactivate is a key feature of its pathophysiology.

Preventing herpes simplex infection involves reducing the risk of transmission. For oral herpes, avoid sharing personal items like toothbrushes or lip balm with an infected person. For genital herpes, using condoms and dental dams during sexual activity can lower the risk of transmission. Individuals with herpes should avoid sexual contact during outbreaks and consider suppressive antiviral therapy to reduce the likelihood of spreading the virus.

Herpes simplex infection is a common viral condition caused by HSV-1 and HSV-2, leading to oral and genital sores. While there is no cure, antiviral medications can manage symptoms and reduce transmission. The virus remains in the body for life, with the potential for recurrent outbreaks. Understanding the nature of the infection and taking preventive measures can help individuals manage the condition effectively.

If you suspect you have herpes simplex infection, it's important to seek medical advice for proper diagnosis and management. Remember that many people live with herpes and lead healthy lives. Open communication with partners and healthcare providers, along with adherence to treatment plans, can help manage the condition and reduce the risk of transmission.

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3. Murray PR, Rosenthal KS, Pfaller MA. Medical Microbiology. Seventh edition. Philadelphia: Elsevier/Saunders; 2013.
4. Munawwar A, Singh S. Human Herpesviruses as Copathogens of HIV Infection, Their Role in HIV Transmission, and Disease Progression. J Lab Physicians. 2016;8(1):5-18.
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6. Corey L, Wald A. Maternal and Neonatal HSV Infections. The New England journal of medicine. 2009;361(14):1376-1385.
7. Mandell GL, Bennett JE, Dolin R. Mandel, Douglas and Bennett's Principles and Practice of Infectious Diseases. 8th ed. Philadelphia, Pennsylvania: Churchill Livingstone; 2015