Herpes simplex infection is a term encompassing a wide range of infections that can be caused by herpes simplex viruses (HSV-1 and HSV-2). Mucocutaneous, oropharyngeal, genital, central nervous system, disseminated and systemic forms have been identified in children, adults, pregnant women, and neonates. An early diagnosis, achieved through a meticulous workup and isolation of the virus in body fluids or from skin lesions, is imperative, as the infection can be life-threatening without adequate therapy.
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 . 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   . 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 . In the literature, the following clinical entities have been described       :
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   . 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    . 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   . 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.