Herpes Simplex Virus

Infections with the herpes simplex virus can be primary or recurrent and are common in both children and adults.
Most primary HSV infections occur in childhood and are asymptomatic or subclinical.
HSV infections can affect mucosal and/or cutaneous surfaces and are characterized by tingling, burning, and painful vesicles on an erythematous base.
The most common clinical presentations of HSV infection in children are herpetic gingivostomatitis, herpes labialis, or eczema herpeticum, an HSV superinfection of atopic dermatitis.
The pathogenesis and clinical manifestations of HSV in adults are discussed in Chapter 17: Mucocutaneous Manifestations of Viral Infections.

Primary HSV infection results from direct contact with infected secretions or the mucocutaneous lesion itself.
After an incubation of days to weeks, a mucocutaneous eruption may occur or the infection may be subclinical resulting only in the development of HSV antibodies.
The virus then remains latent in the sensory root ganglion.

Herpes Gingivostomatitis

Herpetic gingivostomatitis is most often seen in infants and young children and initially presents with mouth pain, irritability, and not wanting to eat or drink.
Lesions present as painful, small vesicles on an erythematous base that rapidly evolve into shallow ulcers on the palate, tongue, or gingivae.
Gums may be red, swollen, and bleed easily and regional lymphadenopathy is often present.
Is usually self-limited and lesions heal within 1 to 2 weeks.
Some patients may require IV hydration and systemic pain control in addition to antiviral therapy.

Herpes Labialis

Herpes labialis, also known as a cold sore, is a herpes infection of the lips that usually occurs on the vermilion border. Occasionally, other areas of the face are involved (Fig. 6.13).
Typically presents with a prodrome of burning, tingling, or itching of the skin that occurs 1 to 2 days before the outbreak.
An outbreak initially starts with a pink red edematous papule that quickly evolves into a painful vesicle or cluster of vesicles on an erythematous base.
Self-resolves without sequelae in 1 to 2 weeks; early treatment can hasten resolution.

Cutaneous Herpes Infections

Grouped small vesicles on an erythematous base can appear anywhere; when deep seated and on the distal finger is termed herpetic whitlow.

Eczema Herpeticum

Also known as Kaposi varicelliform eruption (KVE), eczema herpeticum represents a herpetic superinfection of atopic dermatitis or other chronic skin disease.
Often initially presents with prodrome of fever and malaise.
Later, the characteristic herpes lesions—painful vesicles and erosions—will appear on the diseased skin (Fig. 6.14).
Eczema herpeticum can occur in a localized area of diseased skin or be extensive and widespread.
Complications include bacterial superinfection, dehydration, and herpetic keratoconjuctivitis via direct extension if lesions are present on the face.
Extensive cases may require hospitalization for IV antiviral therapy and IV hydration.

Neonatal Herpes Simplex

Neonatal herpes simplex occurs when newborns are exposed to HSV-2 via the birth canal of an actively infected mother. Less often, infection may occur postnatally or in utero.
Infection is most likely to occur when the mother has a primary infection during a vaginal delivery.
Disease usually occurs within the first 4 weeks of life and may present with skin, eye, and/or mucous membrane lesions (SEM disease); central nervous system (CNS) involvement; or disseminated disease.
SEM disease has the best prognosis. Disseminated and CNS disease and can result in serious morbidity and mortality.

Outline
Herpes Gingivostomatitis
Herpes Labialis
Cutaneous Herpes Infections
Eczema Herpeticum
Neonatal Herpes Simplex

Diagnosis is based on clinical recognition.
A Tzanck smear of vesicle contents showing multinucleated giant cells can support the diagnosis.
The herpes virus can be detected from vesicular fluid or tissue with a viral culture, polymerase chain reaction (PCR), or via direct fluorescent antibody testing.

Differential Diagnosis

Herpetic Gingivostomatitis

Herpangina

Painful oral ulcers usually caused by a strain of the Coxsackie virus; often mistaken for herpetic gingivostomatitis.
Presents with pain, refusal to eat, and high fever.
Lesions present as shallow ulcerations with the rim of erythema clustered on the tonsils and soft palate.

Hand-Foot-and-Mouth Disease (Discussed in Chapter 7: Viral and Bacterial Exanthems)

Characteristic exanthem and enanthem caused by an enterovirus.
Presents with prodrome of fever and malaise followed by characteristic vesicles or shallow erosions often with a rim of erythema on the tongue or buccal mucosa.
On the skin, grayish white tense vesicles on an erythematous base are usually present on the palms, soles, and in the diaper area.

Aphthous Ulcers (Discussed in Chapter 21: Disorders of the Oral Cavity, Lips, and Tongue)

Recurrent round or oval sores or ulcers with erythematous rim on the inside of the lips and cheeks or underneath the tongue.
Lesions are painful.
As with herpes simplex, the lips and gingiva are usually affected, and the back of the throat is spared.

Stevens-Johnson Syndrome (Discussed in Chapter 27: Diseases of Cutaneous Vasculature)

Severe drug reaction characterized by blisters and erosions in the mouth and lips often accompanied by blisters on the skin and other mucous membranes.
History of medication ingestion.

Herpes Labialis

Impetigo (Discussed in Chapter 5: Superficial Bacterial Infections)

Superficial bacterial infection of the skin.
Thin erosions with characteristic honey-colored crusts.

Recurrent Aphthous Stomatitis (see Chapter 21: Disorders of the Oral Cavity, Lips, and Tongue)

Cutaneous Herpes Infections

Bullous Impetigo (Discussed in Chapter 5: Superficial Bacterial Infections)

Superficial bacterial infection of the skin.
Causative organism produces an epidermolytic toxin that results in bullae. Bullae easily rupture and a crusted erosion or collarette of scale remains.

Allergic Contact Dermatitis (Discussed in Chapter 13: Eczema and Related Disorders)

Edematous, eczematous pink plaques with overlying vesicles in a geometric distribution corresponding to area of contact with the allergen.

Management of Pediatric HSV Infections

General Principles

The goals of treatment for any mucocutaneous herpes infection are pain reduction, shortening course of eruption, and preventing dehydration.

Systemic Treatments

Systemic antiviral therapy with acyclovir or valacyclovir can shorten the duration of the illness especially if initiated within 1 to 2 days of symptoms.
Dosage:
- Acyclovir
  - 200 mg/5 mL suspension; 200-mg capsules, 400- and 800-mg tablets.
  - Initial infection:
    - 2 to 12 years old—1,200 mg/day divided q8h for 7 to 10 days (max 80 mg/kg/day).
    - >12 years old—1,000 to 1,200 mg/day divided q8h for 7 to 10 days (max 1,200 mg/day).
  - Recurrence:
    - 2 to 12 years old—1,200 mg/day divided q8h for 5 days (max 80 mg/kg/day);
    - >12 years old—1,000 to 1,200 mg/day divided q8h for 3 to 5 days (max 1,200 mg/day).
- Valacyclovir
  - 500- and 1,000-mg tablets.
  - Initial infection: >12 years old—1 g, twice daily for 7 to 10 days.
  - Recurrence: >12 years old—2 g, twice daily × 1 day.

Topical Treatments

Topical antiviral treatments are overall not as effective as systemic agents and include:
- Acyclovir 5% cream or ointment (Zovirax): apply 5×/day × 5 days.
- Penciclovir 1% cream (Denavir): apply every 2 hours while awake × 4 days.
- Docosanol 10% cream (Abreva): apply 5×/day until healed.
- Xerese (acyclovir 5% and hydrocortisone 1%) cream: apply 5×/day × 5 days.

Pain Control

Topical anesthetic agents such as lidocaine-containing creams are helpful for pain.
Compounded mixtures of diphenhydramine elixir, Kaopectate or Maalox, and viscous lidocaine (often called “magic mouthwash”) have been used successfully as a swish and spit or swish and swallow to help lessen oral pain and help facilitate oral intake.
Oral nonsteroidal anti-inflammatories (NSAIDs) such as ibuprofen taken can also be beneficial for reducing pain and inflammation.

Hydration

Some children may require hospitalization for IV hydration.

Eczema Herpeticum (Kaposi's Varicelliform Eruption [KVE])

In addition to systemic antivirals, eczema herpeticum should also be treated with meticulous skin care including using thick bland emollients to all areas with vesicles and erosions.
Once most healing has occurred, the underlying skin disease should be treated with topical anti-inflammatory agents.

Neonatal Herpes Simplex

Often requires aggressive inpatient and/or intensive medical care including IV antivirals and supportive care.

Helpful Hint

Use oral anti-inflammatories such as acetaminophen or ibuprofen to help with HSV associated pain.

Point to Remember

Initiate antiviral treatment at first sign of prodrome for best chance of shortening course of eruption.

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Basics ⬇

Pathogenesis ⬆ ⬇

Clinical Variant ⬆ ⬇

Diagnosis ⬆