Herpes Simplex

Herpes Simplex Virus (HSV) infection is a common viral disease caused by HSV-1 or HSV-2, belonging to the Herpesviridae family.

• HSV-1 is primarily associated with oral infections (cold sores or fever blisters).

• HSV-2 predominantly causes genital infections.

• The virus establishes latency in sensory ganglia (trigeminal ganglion for HSV-1, sacral ganglion for HSV-2) and may reactivate periodically, causing recurrent lesions.

• Transmission occurs via direct contact with infected secretions, including saliva, genital secretions, or skin-to-skin contact.

Epidemiology:

• HSV infections are highly prevalent worldwide, with most adults having HSV-1 exposure by adolescence.

• HSV-2 prevalence is higher in sexually active adults.

• Immunocompromised individuals (HIV, transplant patients) are at higher risk of severe or atypical presentations.

Signs & Symptoms

Primary infection (first exposure):

• Fever, malaise, headache, myalgia

• Painful vesicular lesions on oral or genital mucosa

• Swelling and tenderness of regional lymph nodes

• Oral HSV-1: gingivostomatitis, pharyngitis

• Genital HSV-2: vesicles, erosions, dysuria, pruritus

Recurrent infection:

• Prodrome of burning, tingling, or itching at the affected site

• Grouped vesicles on an erythematous base

• Lesions heal spontaneously within 7–14 days

• Recurrences are usually milder than primary infections

Complications:

• Herpetic whitlow (finger infection)

• Herpes keratitis (ocular infection)

• Encephalitis (rare, more common with HSV-1)

• Neonatal herpes (if transmitted during delivery, can be severe)

Diagnostic Criteria

• Clinical diagnosis is usually sufficient:

  • Painful grouped vesicles on erythematous base

  • Regional lymphadenopathy

  • History of prior lesions or prodrome

• Laboratory confirmation may be done for atypical cases:

  • Polymerase Chain Reaction (PCR) for HSV DNA

  • Tzanck smear (multinucleated giant cells)

  • Serology (HSV IgM/IgG) to differentiate primary vs recurrent infection

Investigation

• Clinical evaluation is primary

• Viral culture or PCR for HSV from vesicular fluid

• Serology to determine past exposure or primary infection

• Ophthalmology referral if eye involvement is suspected

• Neonatal evaluation if HSV exposure during birth

Treatment

Non-Pharmacological Treatment

• Maintain skin hygiene and avoid scratching

• Pain relief with cold compresses or topical anesthetics

• Avoid close contact to prevent transmission

• Educate patients on sexual and household transmission precautions

Pharmacological Treatment

Primary or severe infection:

• Acyclovir 400 mg orally 3 times daily for 7–10 days

• Valacyclovir 1 g orally twice daily for 7–10 days (better oral bioavailability)

• Famciclovir 250 mg orally 3 times daily for 7–10 days

Recurrent infection (episodic therapy):

• Acyclovir 400 mg orally 3 times daily for 5 days

• Valacyclovir 500 mg orally twice daily for 3 days

Suppressive therapy (frequent recurrences):

• Acyclovir 400 mg orally twice daily

• Valacyclovir 500 mg orally daily

• Duration may be months to years, based on frequency of recurrences

Topical treatment:

• Topical acyclovir cream 5 times daily for 5–7 days may shorten duration but is less effective than oral therapy

Special Considerations:

• Pregnancy: Use acyclovir for primary genital HSV, especially near delivery

• Neonatal herpes: Immediate IV antiviral therapy (acyclovir) is essential

• Immunocompromised patients: Higher doses and longer duration may be required

Prevention

• Avoid direct contact with active lesions

• Barrier protection (condoms) for genital HSV

• Hand hygiene, especially with oral HSV

• Suppressive antiviral therapy to reduce recurrence and transmission

• Screening and education during pregnancy to prevent neonatal HSV