Herpes simplex infection
Herpes viruses comprise a large family of DNA containing viruses which affect both animals and human. These viruses tend to persist in the body for the whole life, causing periodic disease recurrences.
Herpes simplex viruses 1 and 2 are also known as Herpesvirus hominis, they belong to the alpha herpesvirus group. HSV possesses an internal core with a linear double-stranded DNA. Both HSV-1 and HSV-2 cause common infections with variable clinical manifestations. Herpes simplex infection tend to be more severe in immunosuppressed children and adults and may affect various sites and multiple organs causing disseminated herpes. Disseminated disease may occur with widespread cutaneous, mucosal, and visceral involvement.
Causes and risk factors for HSV dissemination
- Individuals with underlying skin disease;
- Immunocompromised individuals (HIV-positive individuals or those who suffer from other immune system disorders; patients after organ transplantation; those who have cancer);
- Mucocutaneous herpes:
Primary HSV-1 infection typically manifests with gingivostomatitis and pharyngitis. When the lesions appear a person experiences fever, sore throat malaise, itching, burning sensations, myalgias, inability to eat, irritability, cervical adenopathy, and mucosal edema. Tingling and pain may precede the occurrence of sores.
Vesicular rash which looks like small blisters is distributed on the hard palate, the tongue, the gingiva, and around the lips. These lesions, also known as fever blisters or cold sores tend to rupture, leaving gray-white ulcers.
- Central nervous system lesions:
The virus may spread into the brain via the ganglia and results in HSV encephalitis. HSV encephalitis presents with headache, fever, altered consciousness, seizures, memory loss, anosmia (absence of the smell perception), olfactory hallucinations, speech disorders, and behavioral disturbances.
HSV meningitis may occur.
HSV-1 infection was reported to be related to Bell’s palsy (the paralysis of the mandible).
- Genital herpes:
The first episode of genital herpes manifests with fever, headache, general malaise, and muscular pain. Pain, itching, dysuria, vaginal and urethral discharge, and the painful enlargement of the local lymph nodes are characteristic. Widely spaced bilateral lesions on the genitalia are observed on examination, including vesicles, pustules, painful erythematous ulcers, and crusting. A clear mucoid discharge and dysuria (painful urination) may also be present. The cervix and urethra are also involved.
In males the lesions typically are observed on the glans, or shaft, of the penis. In females the labia minora, labia majora, and perineum are the most frequently affected.
- Central nervous system lesions:
Read more: Herpes Genitalis
- Eye infection:
HSV keratitis, blepharitis, follicular conjunctivitis, and chorioretinitis may develop.
- Visceral organs infection:
The esophagus, lungs and liver are commonly affected. HSV pneumonitis or tracheobronchitis may occur.
- Other sites of HSV infection:
HSV may also affect the joints, adrenal glands pancreas, small and large intestines, and bone marrow.
The diagnosis is made based upon clinical features and laboratory tests such as DNA or PCR tests and virus cultures.
Multiorgan involvement may lead to the failure of the internal organs and may even result in death.
Disseminated herpes requires systemic treatment with administration of high doses of acyclovir.
Intravenous acyclovir (5 mg/kg every 8 hours) is administered.
In case of acyclovir-resistant HSV infection intravenous foscarnet (40 mg/kg every 8 hours) should be administered. Topical application of trifluorothymidine or 5% cidofovir gel may be also effective.