Herpes simplex is a disorder of an infectious nature caused by the virus of the same name (Herpes simplex virus – HSV type 1 or 2) and characterized by the appearance of the typical bubbles, ulcerations, and scabs (herpetic eczema), predominantly in the skin area surrounding the lips (in this case it is also called “herpes labialis”), or, more rarely, at the level of the conjunctiva and cornea of the eye and genital mucous membranes.
When it affects the skin area around the mouth, the disorder is harmless and without implications for general health, but undoubtedly annoying, especially when it tends to recur often.
In the case of ocular, oropharyngeal (gingivostomatitis and herpetic pharyngitis) or genital involvement, however, HSV infection can create significant discomfort and expose one to the risk of complications.
Occasionally, especially among those who work in health care (doctors, nurses, etc.), HSV can cause “herpetic paterecium” corresponding to a partially ulcerated and swollen lesion at the level of the distal phalanx of a finger.
In rare cases, herpes simplex can also infect the central nervous system by causing herpetic encephalitis (associated with seizures and with a course that can be very severe) or herpetic meningitis (characterized by spinal cord involvement at the lumbosacral level and, often, by transient urinary retention and constipation).
In exceptional cases, in severely immunocompromised people and when the virus infects wounds, very serious systemic HSV infections can develop.
Herpes simplex can infect even infants in the first days or months of life.
In most cases, neonatal herpes is transmitted from mother to baby at delivery through contact with infected vaginal secretions (HPV2), but it can sometimes affect babies born to mothers with no signs of active or prior HSV infection.
Of all the HSV infections mentioned, herpes labialis is by far the most common and is widespread in the general population of all ages, but it most often affects children/adolescents and people with specific susceptibility who are relatively immunocompromised or weakened by other illnesses or stressful situations.
The other forms of HSV infection are of much less frequent occurrence.
