Herpes Simplex Virus

Herpes Simplex Virus

Etiology 

It is caused by herpes virus hominis, a DNA virus, and presents in many forms, usually associated with a vesicular eruption.

Clinical Features 

In the neonatal form the infection is usually acquired during passage through the birth canal. The virus causes widespread infection of many organs without vesicular (herpetic) lesions on the skin or mucosa. There may be any combinition of hepatitis, myocarditis, pneumonitis and severe systemic upset. Purpura and hepatosplenomegaly are common.

Older children may have:

1. Primary infection, seen in those infected for the first time and thus having no immunity. There is severe vesicular stomatitis with lesions on the lips and near the angles of the mouth. The child has high fever, pain in the lesions and drooling of saliva. He refuses to eat or drink and becomes dehydrated.
2. Secondary or recurrent herpes occurs in children who had previous herpes infection and have some immunity. It most commonly occurs near the lips but may occur on the ski n or mucous membranes elsewhere as clear thin-walled vesicles with associated itching. They usually scab and heal in 7-10 days without any treatment.
3. Eczema herpeticum: In an eczematous child, the herpetic lesions rapidly appear and spread over the eczematous skin area with usually severe systemic symptoms. There may be appreciable mortality.
4. Generalized herpetic infection may occur in children with suppressed immunity e.g. with Hodgkin's disease or leukaemia, children on steroids or on anti-cancer therapy.
5. Genital herpes 
6. Keratitis/conjunctivitis may also occur.
7. Herpes encephalitis or meningoencephalitis may occur at any age with fever, convulsions, paralyses, cough, and death in many.

Laboratory Diagnosis 

It can be made by: finding multinucleated giant cells and intracellular inclusions in scrapings from lesions; virus serology and viral culture.

Treatment 

Topical application of 5-lodo-2-deoxyuridine is effective against skin and mucous membrane lesions. Other drugs used are: acyclovir, trifluridine and vidarabine.