Herpes Simplex Virus Growth Cycle and Infection

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Questions and Answers

Which of the following is a primary infection caused by the Varicella-Zoster Virus (VZV)?

Immunosuppression

Chickenpox (correct)

Herpes Zoster

HIV

What is a common symptom of Herpes Zoster (Shingles)?

Nasal congestion

Widespread rash

High fever

Unilateral vesicles (correct)

In which age group is Herpes Zoster most commonly seen?

Children

Infants

Teenagers

Adults and elderly (correct)

What indicates an increased risk of developing Herpes Zoster in patients?

Immunosuppressive treatments Signup and view all the answers

What is the name for Herpes Zoster that occurs without dermatomal lesions?

Zoster sine eruption Signup and view all the answers

Which branch of the trigeminal nerve is most commonly affected by Herpes Zoster?

Ophthalmic branch Signup and view all the answers

What typically happens to chickenpox vesicles after 1-2 weeks?

They crust and fall off Signup and view all the answers

What symptom could precede the appearance of vesicles in Herpes Zoster?

Deep aching or burning pain Signup and view all the answers

What is the first step in the virus growth cycle as described?

Adsorption Signup and view all the answers

During which phase of the virus growth cycle does the viral DNA enter the nucleus?

Penetration Signup and view all the answers

What is a significant symptom of primary herpetic gingivostomatitis?

Severe oral pain Signup and view all the answers

What age group shows the highest incidence of primary herpetic gingivostomatitis?

Children from 1 to 10 years Signup and view all the answers

What distinguishes generalized acute marginal gingivitis in primary herpetic gingivostomatitis?

Appearance without loss of inter dental papillae Signup and view all the answers

What can happen as a result of oral pain in patients with primary herpetic gingivostomatitis?

Poor oral intake Signup and view all the answers

What clinical feature may precede the local lesions of primary herpetic gingivostomatitis?

Swollen lymph nodes Signup and view all the answers

What is a potential risk factor for ocular herpes simplex virus type 1 infection in patients with primary herpetic stomatitis?

Rubbing the eye with a contaminated finger Signup and view all the answers

What is the main effect of vaccination against VZV for adults?

Reduces incidence and severity of HZV and postherpetic neuralgia Signup and view all the answers

Which coxsackie virus infection commonly affects children under 10?

Herpangina Signup and view all the answers

Which statement accurately distinguishes herpangina from primary HSV?

Herpangina primarily affects the posterior part of the oral cavity Signup and view all the answers

What is the primary symptom of acute lymphonodular pharyngitis caused by Coxsackie A 10?

Diffused yellow-white nodules in the oropharynx Signup and view all the answers

What supportive treatment is recommended for herpangina?

Proper hydration and topical anesthetics Signup and view all the answers

Which virus is associated with hand, foot, and mouth disease?

Coxsackie A 16 Signup and view all the answers

What is a characteristic clinical feature of herpangina?

Oral lesions that form rapidly and break down into ulcers Signup and view all the answers

During which season are Coxsackie virus infections, such as herpangina, more likely to occur?

Summer Signup and view all the answers

What is the most common age group affected by EM?

Children under 10 years Signup and view all the answers

What is the central mechanism of the delayed type hypersensitivity reaction related to EM?

Release of cytokines by activated T cells Signup and view all the answers

Which clinical manifestation is considered pathognomonic for EM?

Target or iris lesion Signup and view all the answers

Which site is the most commonly affected orally in EM?

Lips Signup and view all the answers

HSV infection is most commonly associated with which type of hypersensitivity reaction in EM?

Type III hypersensitivity Signup and view all the answers

What type of lesions are characteristic of EM?

Target or iris lesions Signup and view all the answers

What complication may arise from severe oral findings in EM?

Difficulty in swallowing Signup and view all the answers

What characteristic of HSV infection differentiates it from lesions in EM?

Absence of HSV culture from the lesion Signup and view all the answers

Which area is affected by the ophthalmic division of herpes zoster?

Forehead, upper eyelids, and cornea Signup and view all the answers

What is a common characteristic of lesions caused by maxillary division involvement?

Painful and unilateral with an erythematous base Signup and view all the answers

Which structure is particularly affected in Ramsay Hunt syndrome?

Geniculate ganglion Signup and view all the answers

What can result from corneal involvement due to herpes zoster?

Blindness Signup and view all the answers

What is the typical duration for post herpetic neuralgia to persist after the rash has resolved?

30-120 days Signup and view all the answers

Which description best fits the oral lesions resulting from herpes zoster?

Painful, unilateral, grouped vesicles Signup and view all the answers

What is a distinctive feature of the ulcerations caused by herpes zoster?

They are usually small and rounded Signup and view all the answers

Which area of the face is affected by the mandibular division of herpes zoster?

Lower lip and buccal mucosa Signup and view all the answers

Study Notes

Herpes Simplex Virus (HSV) Growth Cycle

HSV binds to keratinocytes and neurons on the cell plasma membrane
Enters the cytoplasm by endocytosis
Uncoats and DNA enters the nucleus
Thousands of viral copies are generated
The nucleus swells (ballooning degeneration)
DNA is packaged into capsids on the nuclear membrane and acquires an envelope
The virus is released extracellularly
Keratinocytes undergo lysis and necrosis

HSV-1 Primary Infection

HSV-1 causes primary and recurrent infections
In the acute phase, HSV-1 causes herpetic gingivostomatitis
Primary herpetic gingivostomatitis occurs in patients with no prior HSV-1 infection
Transmission occurs through inoculation of skin, mucosa, and eyes via infected secretions
Commonly misdiagnosed as teething
Uncommon before 6 months due to maternal IgG antibodies crossing the placental barrier
Common in children from 1-10 years, peaking at 2-3 years
Adult onset primary HSV infection has the same signs and symptoms, but it is more severe

Clinical Features

Prodromal symptoms precede the local lesions by 1-3 days
Prodromal symptoms include fever, headache, myalgia, malaise, loss of appetite, nausea, and vomiting
Submandibular and upper deep cervical lymph nodes are enlarged
Vesicles develop on the oral, gingival, or circum-oral tissues
Vesicles quickly rupture leaving ulcers that are:
- Shallow and round
- Discrete and ragged
- May coalesce to form larger ulcers with scalloped borders
- Few millimeters to 1 cm in size
- Very painful
- Surrounded by an erythematous zone

Clinical Manifestations

Oral pain leads to poor oral intake
Patients may require hospitalization for hydration
Pharyngitis causes swallowing difficulties and excessive salivation
An important diagnostic criteria is the appearance of generalized acute marginal gingivitis without loss of interdental papillae
Ocular herpes simplex virus type 1 infection can occur from rubbing the eye with saliva-contaminated fingers

Varicella Zoster Virus (VZV) Infections

VZV is responsible for two major clinical infections:
- Chickenpox (Varicella)
- Herpes Zoster (Shingles)

Chickenpox (Primary VZV Infection)

A childhood disease characterized by:
- Mild systemic symptoms (low-grade fever and malaise)
- Generalized intensely pruritic skin vesicles (trunk and face)
Vesicles turn cloudy and pustular, burst, and crust
Crusts fall off after 1-2 weeks
Minor acute ulceration can occur orally
After the primary infection heals, VZV becomes latent in the dorsal root ganglia of spinal nerves or extramedullary ganglia of the cranial nerves
VZV reactivation in some individuals produces herpes zoster infection (HZI)

Herpes Zoster (Shingles)

HZI is commonly called shingles
The incidence increases with age and the degree of immunosuppression

Herpes Zoster Virus (Shingles) Clinical Manifestations

Usually seen in adults and the elderly, rare in children
Patients at high risk include those with:
- HIV
- Leukemia
- Lymphomas
- Irradiation
- Immunosuppressive drugs
Starts with a prodrome of deep, aching or burning shooting pain along the affected nerve, usually unilateral
There is little or no fever
Commonly involves the sensory branches of the trigeminal nerve
After 2-4 days, unilateral vesicles appear on an erythematous base along the course of the affected nerve
Vesicles appear in clusters, giving the clinical picture of single dermatome involvement (dermatomic distribution)
Vesicles crust in one week, and healing takes place after 3-4 weeks

Herpes Zoster Diagnostic Problem

Occasionally, HZI may occur without the appearance of dermatomal lesions
This is called zoster sine eruption or zoster sine herpes
Diagnosis is based on increased antibody titers of the virus

Herpes Zoster Oral Manifestations

The trigeminal nerve (V) may be affected with involvement of one or more of its branches
Oral and facial lesions result from HZ of the second and third divisions of the trigeminal nerve, but involvement of the first is more common

Ophthalmic Division Involvement

Ophthalmic nerve affects the skin covering the forehead, upper eyelids, and cornea
Corneal involvement may lead to blindness

Maxillary Division Involvement

The maxillary division involvement gives rise to unilateral lesions that affect the:
- Upper lip
- Hard and soft palate
- Vestibule of the upper jaw
- Skin of the cheek and side of the nose
Lesions present as vesicles that rupture to leave erosions and ulcerations
Ulcers are:
- Painful
- Unilateral
- Small
- Shallow
- Rounded with an erythematous base

Mandibular Division Involvement

The mandibular division affects the:
- Lower face
- Oral structures: lower lip, tongue, buccal mucosa, vestibular of the lower jaw
Lesions present as vesicles that rupture to leave erosions and ulcerations
Ulcers are:
- Painful
- Unilateral
- Small
- Shallow
- Rounded with an erythematous base

Herpes Zoster Complications

Post herpetic neuralgia (uncommon in the oral cavity)
Ramsay Hunt syndrome

Post Herpetic Neuralgia

Neuralgic pain may persist after the rash has resolved for 30-120 days (some experience pain for years)
It is due to inflammation and fibrosis of the affected nerve
It usually affects elderly patients

Ramsay Hunt Syndrome

A special form of HZ affecting the facial nerve via infection of the geniculate ganglion

VZV Vaccination

Vaccination for the prevention of VZV infection has been shown to:
- Reduce varicella outbreaks
- Increase antibody titer in adults
- Reduce the incidence and severity of HZI and postherpetic neuralgia

Acute Multiple Lesions

Herpes virus infection:
- Herpes simplex infection
- Varicella zoster infection
Coxsackie virus infection:
- Herpangina
- Acute lymphonodular infection
- Hand, foot, and mouth disease
Erythema multiforme
ANUG (acute necrotizing ulcerative gingivitis)

Coxsackie Virus Infection

Coxsackie viruses are RNA enteroviruses separated into groups A and B
There are about 23 types of Coxsackie virus A and 6 types of Coxsackie virus B
CVA is important to dentists because it can induce infections in the mouth and oropharyngeal region:
- Herpangina
- Hand, foot, and mouth disease
- Acute lymphonodular pharyngitis

Herpangina

Derives from herpes (vesicular eruption) and angina (inflammation of the throat)
CVA (1-10, 16, 22) are the most common viruses isolated from the disease
Children under 10 are usually affected
Patients develop fever, headache, and myalgia that usually lasts for 1-3 days
Usually occurs in epidemics during the summer
Oral manifestations:
- First oral symptoms are sore throat and pain on swallowing
- Erythema of the oropharynx, soft palate, and tonsillar pillars
- Small vesicles form but rapidly break down to 2-4 mm ulcers

Herpangina Clinical Differentiation from Primary HSV

Occurs in epidemics
Tends to be milder with smaller lesions than HSV
Primarily affects the posterior part of the oral cavity and pharynx, while HSV affects primarily the anteriopart
Generalized acute gingivitis does not occur
A smear does not show any giant cells or ballooning degeneration of the nucleus

Herpangina Treatment

Self-limiting disease, treatment is supportive including proper hydration and topical anesthesia when eating or swallowing is difficult

Acute Lymphonodular Pharyngitis

Caused by Coxsackie A 10
Patients present with a sore throat
The development of diffuse small yellow-white nodules in the oropharynx is more commonly encountered than vesiculation and ulceration
Self-limiting disease

Hand, Foot, and Mouth Disease

Caused by Coxsackie A 16 in the majority of cases

Erythema Multiforme (EM)

Recurrent EM has been shown to be related to HSV infection in 65-70% of cases

EM Etiology

May be a type III hypersensitivity reaction
It is postulated that HSV antigen incites a T-cell mediated delayed type hypersensitivity reaction
- Destroying epithelial cells
- HSV is not cultured from the lesions

EM Type III Hypersensitivity Reaction (Immune Complex)

Immune complex is deposited in various tissues which triggers inflammation and tissue damage

EM Type IV Delayed Type Hypersensitivity Reaction (Stomatitis Venenata)

Mechanism:
- Antigen (Ag) activates sensitized T-cells to release factors (cytokines) that stimulate other leukocytes.
Mediators:
- Activated T-helper cells
- Activated macrophages

EM Clinical Manifestations

Most frequent in children (20%), and young adults (20-40 years)
Rare after age 50
Prodrome of fever, malaise, headache, sore throat, rhinorrhea, and cough
Skin lesions appear rapidly over a few days and begin as red macules that become papular
The most common sites of involvement are the extremities, face, and neck
Skin lesions may take several forms, hence the term multiforme
The classical skin lesion is called a target or iris lesion, which consists of a central bulla or pale area or necrosis surrounded by edema and concentric rings of erythema
- This is a pathognomonic sign of EM
Genital and ocular sites may be affected

EM Oral Findings

Range from mild erythema and erosion to painful ulceration
When severe, ulcers may be large and bleeding, causing difficulty in eating, drinking, and swallowing
Bloody-tinged saliva can occur
The most common affected site orally is the lips, buccal mucosa, tongue, and labial mucosa
The gingiva is rarely affected
Must be differentiated from other causes of acute multiple lesions. Especially primary herpes simplex infection

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Description

This quiz covers the growth cycle of the Herpes Simplex Virus (HSV) and focuses specifically on HSV-1 primary infections. It outlines the phases of viral entry, genome replication, and the clinical implications of infections, particularly in children. Test your understanding of the mechanisms of HSV infection and its transmission.