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Questions and Answers
What is a key characteristic of allodynia as described in the content?
What is a key characteristic of allodynia as described in the content?
Which of the following is NOT an important feature for diagnosing postherpetic neuralgia (PHN)?
Which of the following is NOT an important feature for diagnosing postherpetic neuralgia (PHN)?
What is a recommended treatment for mild cases of postherpetic neuralgia?
What is a recommended treatment for mild cases of postherpetic neuralgia?
In which scenarios should antiviral therapy be initiated within 72 hours of rash onset?
In which scenarios should antiviral therapy be initiated within 72 hours of rash onset?
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Which of the following antiviral drugs is specifically noted as a pregnancy category B drug?
Which of the following antiviral drugs is specifically noted as a pregnancy category B drug?
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What is the primary difference between HSV-1 and HSV-2 in terms of the infections they typically cause?
What is the primary difference between HSV-1 and HSV-2 in terms of the infections they typically cause?
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What are the typical sites of involvement for HSV-1 and HSV-2?
What are the typical sites of involvement for HSV-1 and HSV-2?
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What is NOT a characteristic of the primary infection stage of HSV infection?
What is NOT a characteristic of the primary infection stage of HSV infection?
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Which of the following correctly describes the latent infection phase of HSV?
Which of the following correctly describes the latent infection phase of HSV?
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In which condition is cytomegalovirus (HHV-5) particularly associated as a long-term outcome?
In which condition is cytomegalovirus (HHV-5) particularly associated as a long-term outcome?
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What is the expected incubation period (IP) for primary HSV infection in children?
What is the expected incubation period (IP) for primary HSV infection in children?
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Which of the following viruses causes chickenpox and shingles?
Which of the following viruses causes chickenpox and shingles?
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What is the primary advantage of using the Direct Fluorescence Antibody test for HSV diagnosis?
What is the primary advantage of using the Direct Fluorescence Antibody test for HSV diagnosis?
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Which of the following statements about serology for HSV is true?
Which of the following statements about serology for HSV is true?
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What is the recommended management for mild uncomplicated HSV eruptions?
What is the recommended management for mild uncomplicated HSV eruptions?
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In which situation would Cidofovir be considered for antiviral therapy?
In which situation would Cidofovir be considered for antiviral therapy?
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What characterizes the rash associated with Varicella (Chickenpox)?
What characterizes the rash associated with Varicella (Chickenpox)?
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Which statement about the transmission of Varicella is accurate?
Which statement about the transmission of Varicella is accurate?
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What is the common prodromal phase symptom of Varicella?
What is the common prodromal phase symptom of Varicella?
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What is the incubation period for Varicella before symptoms develop?
What is the incubation period for Varicella before symptoms develop?
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What is a possible complication of chickenpox if lesions are large or infected?
What is a possible complication of chickenpox if lesions are large or infected?
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During which season is Varicella most prevalent?
During which season is Varicella most prevalent?
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What triggers recurrent infections of HSV-1 and HSV-2?
What triggers recurrent infections of HSV-1 and HSV-2?
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Which site is most commonly affected by herpes labialis?
Which site is most commonly affected by herpes labialis?
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In which population is herpetic whitlow most commonly found?
In which population is herpetic whitlow most commonly found?
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What is the primary treatment for neonatal herpes?
What is the primary treatment for neonatal herpes?
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What condition is characterized by painful oral ulcers and high-grade fever?
What condition is characterized by painful oral ulcers and high-grade fever?
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Which of the following is a severe manifestation of herpes simplex infection in compromised hosts?
Which of the following is a severe manifestation of herpes simplex infection in compromised hosts?
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Which of the following describes the characteristic symptoms of primary genital herpes in women?
Which of the following describes the characteristic symptoms of primary genital herpes in women?
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What is the primary cause of eczema herpeticum?
What is the primary cause of eczema herpeticum?
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How does the frequency of recurrent genital herpes change over time?
How does the frequency of recurrent genital herpes change over time?
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What is the most common neurologic effect associated with varicella?
What is the most common neurologic effect associated with varicella?
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Which condition is NOT listed as a complication of varicella?
Which condition is NOT listed as a complication of varicella?
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What constitutes the recommended treatment for normal adolescents and adults with varicella?
What constitutes the recommended treatment for normal adolescents and adults with varicella?
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What risk factor can lead to the reactivation of VZV, resulting in herpes zoster?
What risk factor can lead to the reactivation of VZV, resulting in herpes zoster?
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What is the significant risk during pregnancy if maternal VZV infection occurs within the first 20 weeks of gestation?
What is the significant risk during pregnancy if maternal VZV infection occurs within the first 20 weeks of gestation?
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What is the presentation of severe neonatal varicella?
What is the presentation of severe neonatal varicella?
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Which type of treatment is necessary for immunosuppressed patients with varicella?
Which type of treatment is necessary for immunosuppressed patients with varicella?
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What is one of the first locations VZV travels to after initial infection?
What is one of the first locations VZV travels to after initial infection?
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Which of the following describes Congenital Varicella Syndrome?
Which of the following describes Congenital Varicella Syndrome?
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What is a common presentation of herpes zoster?
What is a common presentation of herpes zoster?
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Study Notes
Introduction
- Viruses consist of only one type of nucleic acid, either DNA or RNA.
Classification
- DNA viruses include herpes viruses, parvovirus, papovaviruses (human papovaviruses), poxviruses (molluscum contagiosum virus), and parapoxviruses (Milker's nodule virus).
- RNA viruses include paramyxovirus (measles virus), rubivirus (rubella virus), picornaviruses (Coxsackie virus A16 and enterovirus 71), and retroviruses (HIV).
Herpes Viruses
- HSV-1 causes herpes labialis.
- HSV-2 causes genital herpes.
- HHV-3 causes chickenpox (varicella) and shingles (herpes zoster).
- HHV-4 causes Epstein-Barr virus (Infectious Mononucleosis and oral hairy leukoplakia).
- HHV-5 causes cytomegalovirus (congenital deafness, blindness due to retinitis in AIDS patients).
- HHV-6 causes roseola infantum.
- HHV-7 causes roseola infantum and pityriasis rosea.
- HHV-8 causes Kaposi's sarcoma.
Herpes Simplex
- Etiology: Caused by herpes simplex virus (HSV). HSV comprises two antigenic types.
- HSV-1 is usually associated with facial infections, mainly in infants and young children.
- HSV-2 is classically found in genital infections, mainly after puberty and transmitted sexually.
- Sites infected by HSV types often overlap.
- Transmission: Via direct contact or droplets of infection (usually in children) and sexual contact (usually in adults).
- Primary infection: Incubation period (3-7 days). Characterized by fever/malaise, burning/painful lesions (vesicles) on erythematous base, grouping tendencies (with tender regional lymph nodes), crusting of lesions, and resolution within 2-6 weeks.
- Latent Infection: HSV gene expression severely restricted in sensory ganglia causing undetectability by host defenses.
- Recurrent infection: Due to reactivation of virus due to risk factors such as old age, immune dysfunction, trauma, stress, etc. Virus travels to the trigeminal ganglion (for HSV-1) or sacral ganglion (for HSV-2) causing recurrent disease.
- Sites of predilection: Outer third of lower lip and perioral areas (herpes labialis).
Clinical Varieties
- Herpes labialis (facial) near vermillion border/perioral areas
- Herpetic gingivostomatitis (high grade fever, painful oral ulcers)
- Eczema herpeticum (Kaposi's varicelliform eruption)
- Herpetic whitlow (infection of digits in dental and medical personnel who don't routinely use gloves)
- Keratoconjunctivitis
- Herpetic folliculitis (mainly beard region in males)
- Herpetic pneumonia (fatal)
- HS encephalitis (seizures, lethargy, irritability, tremors, poor feeding, temperature instability)
- Herpetic gladiatorum (wrestlers)
- Disseminated HS in compromised host
Neonatal Herpes
- 70% due to HSV-2.
- Clinical spectrum: localized infections (skin, eyes, and mouth); CNS disease (severe disseminated disease); sepsis, encephalitis, hepatitis, pneumonia; coagulopathy; fatality up to 50%.
- Incubation period up to 3/52 (weeks). Often diagnosed after hospital discharge.
- 70% of mothers are asymptomatic.
- Treatment: IV acyclovir (250mg/m2 every 8 hours for 7 days).
Genital Herpes
- Primary infection: often asymptomatic, but can manifest with painful/tender erosions on external genitalia, vagina, cervix, buttocks, and perineum (more common and prominent in women). Possible lymphadenopathy/dysuria (in women). Higher percentage of extragenital involvement in women. Can cause urinary retention and aseptic meningitis (10%).
- Recurrent infection: Mildly symptomatic with vesicles lasting about 1 week; frequency of outbreaks typically decreases over time.
Eczema Herpeticum
- Etiology: Due to widespread HSV-1 infection of damaged skin. Occurs in patients with atopic dermatitis, seborrheic dermatitis, scabies, or Darier's and Hailey-Hailey diseases. Patients often appear more toxic/ill.
- Diagnosis and Investigations are key.
Investigations (HSV-1 and HSV-2)
- Tzanck smear (giant multinucleated epithelial cells)
- Nonspecific
- Direct fluorescence antibody test (results available in hours; virus specific)
- Biopsy with immuno-peroxidase staining
- PCR
- Viral culture (results available in 48-72 hours)
- Serology (does not indicate current lesion or its partner)
Management of HSV Infections
- Mild uncomplicated eruptions: No systemic antiviral treatment needed; keep lesions clean and dry; topical antibacterial agents for secondary infections.
- Severe primary infection: Start antiviral therapy.
- Systemic antiviral agents (dosages depend on age- see slide 21).
Antiviral Therapy
- Primary herpes genitalis: Acyclovir cream/ointments (applied 4-5 times) are beneficial.
- Recurrent herpes genitalis: Topical imiquimod may have a beneficial effect in some cases. Topical acyclovir is not beneficial.
- First line drug: IV Foscarnet
- Second line or failure/intolerance: Cidofovir
Varicella (Chickenpox)
- Epidemiology: Very common in childhood, especially during cooler months.
- Infection with VZV (HHV-3). More severe with age/immune suppression.
- Lifelong immunity to natural infection. Prodromal symptoms (fever, malaise, headache) often precede rash by 2-3 days.
- Skin eruption: Dewdrop-like, rose petal; smaller vesicles surrounded by erythema. Lesions develop in different stages.
- Lesions begin on face, spread to trunk, least on peripheral limbs (centripetal distribution).
- Transmission: Direct contact and respiratory droplet
- Contagious period: 4+ days before lesions to crusted lesions.
- Complications: Pneumonia (more common in adults), encephalitis and ataxia (common neurologic effects), osteomyelitis, septicemia, myocarditis, DIC, purpura fulminans, Reye's syndrome, Hepatitis, Acute encephalopathy
- Treatment: Acyclovir (20mg/kg-up to 800mg qid x 5/7)
Varicella (Chickenpox) - Transportation
- During varicella, VZV travels from skin centripetally along sensory fibers to sensory ganglia.
- The virus establishes a latent infection and persists for life.
Varicella (Chickenpox) - Recurrence
- Reactivation under certain conditions (older age, immune suppression, local trauma, etc.).
- Virus reactivates in ganglia.
- Virus spreads down sensory nerve endings, causing clusters of vesicles in dermatome.
- Herpes zoster develops from these clusters.
Varicella in Pregnant Women and Neonates
- Congenital Varicella Syndrome: Maternal infection during first 20 weeks of gestation (fetal).
- Risk of spontaneous abortion (3%) and preterm labor; risk of fetal anomalies (LBW; hypoplastic ribs/limb anomalies, ocular and CNS issues- developmental delays/microphthalmia/cataracts/nystagmus/chorioretinitis; hydrocephalus)
- Neonatal varicella: Maternal primary infection 7 days before to 2 days after delivery. Presents at 0-14 days with vesicles on erythematous base, generalized distribution. Severe cases require treatment with VZIG and IV Acyclovir.
Treatment (Varicella)
- Normal children: Benign self-limiting. Treat symptomatically with oral antihistamines/antipyretics and topical soothing agents (like calamine lotion). Routine acyclovir not typically required.
- Adolescents/Adults: Oral acyclovir (800mg 5 times/day for 7 days) as soon as possible (due to potential for life-threatening pneumonia).
- Immunosuppressed patients: Lesions similar to normal patients but more numerous, necrotic, and larger.
Herpes Zoster (Shingles)
- Etiology: VZV (chickenpox virus) reactivates in sensory root ganglion and remains dormant for years, causing herpes zoster during reactivation.
- Predisposing factors: Older age, underlying HIV infection, immunosuppression (lymphoreticular malignancies, e.g., Hodgkin's disease and leukemia).
- Pain: Almost always present; burning/excruciating/intolerable.
- Zoster sine herpete: Pain without skin lesions.
- Morphology: Closely grouped vesicles on an erythematous base, unlike the random distribution of varicella. Vesicles restricted to dermatome
- Course: Evolves more slowly than varicella; patients older than 50 frequently show more severe eruptions lasting longer (3-4 weeks).
- Complications: Secondary bacterial infection. Disseminated zoster (more than 20 lesions outside dermatome). Rule out underlying lymphoreticular malignancies (e.g., Hodgkin's disease, leukemia), and HIV infections. Involvement of eye. (Hutchinson's sign - vesicles on tip or side of nose innervated by nasociliary branch of trigeminal nerve).
- Swelling of eyelids, Ramsay Hunt syndrome (facial palsy, herpes zoster of external ear, ear pain, vertigo, and deafness), Postherpetic neuralgia.
Postherpetic Neuralgia (PHN)
- Persistent neuralgic pain in affected dermatome after healing of herpes zoster lesions.
- Most common, most troublesome, and intractable complication of herpes zoster.
- Less common/less severe in children. Frequency/severity increases with age.
- Risk factor for PHN is severe pain. Pain may be continuous or spasmodic in form. Allodynia: pain after the slightest touch or from clothing or wind. Can affect sleep routines and daily life.
- Treatment: Requires symptomatic treatment with topical therapy; oral analgesics, nerve blocks. Systemic antiviral treatment needed within the first 72 hrs to avoid this.
Recurrence (HIV)
- HIV-infected patients have a unique tendency for multiple recurrences or to involve multiple dermatomes simultaneously.
Diagnosis
- Diagnosis of herpes zoster (shingles) is based on the following:
- severe burning pain
- unilateral and dermatomal distribution
- grouped vesicular eruptions on an erythematous base
Treatment (Herpes Zoster)
- Mild cases: Require symptomatic treatment using topical therapies (like calamine lotion) and oral analgesics. Avoid topical antiviral agents.
- Severe cases: Parenteral analgesics (e.g., combination of pentazocine and pheniramine maleate) for night-time pain relief. Patient reassurance is also important if the problem has accurately diagnosed.
- Antiviral therapy: Should be started within 72 hours of rash onset.
Indications for Antiviral Therapy
- Patients over 50
- Ophthalmic zoster
- Immunocompromised (or HIV-infected) Patients
- Severe involvement (e.g., disseminated or hemorrhagic or multi-dermatomal lesions)
- Antiviral drugs: Aciclovir, Valaciclovir, Famciclovir
Drugs (Herpes)
- All three drugs are pregnancy category B. Give 1 orally.
- Aciclovir 800mg 5 times/day for 7-10 days
- Valaciclovir 1gm TDS for 7 days
- Famciclovir 250 or 500 mg TDS for 7 days.
- IV antiviral therapy may be indicated for severely compromised patients and advanced AIDS patients.
Epstein-Barr Virus (HHV-4)
- Gamma herpesvirus
- Infects mucosal epithelial cells and B lymphocytes.
- 95% of the population are latently infected by age 20
- Spread via oral secretions
- Causes Infectious Mononucleosis ("glandular fever"); characterized by: Fever, Adenopathy, Splenomegaly, Atypical Lymphocytosis.
- Oral Hairy Leukoplakia: Not a reactivation; a repeated direct infection. Does not scrape off with tongue blade. No treatment needed. This diagnosis should prompt HIV testing.
CMV/HHV-5
- Beta herpesvirus.
- 90% of exposed infants are asymptomatic.
- Other symptoms: Jaundice, Splenomegaly, cerebral calcifications, chorioretinitis, microcephaly, MR, deafness.
- AIDS patients (CD4 counts <50) may show retinitis, cholangitis, colitis, encephalitis, adrenalitis.
- Treatment: ganciclovir, foscarnet, cidofovir.
Roseola Infantum (Exanthem Subitum/6th Disease) - HHV-6
- High fever and LADs (lymphadenopathy).
- Fever lasts 4 days
- Fevers drop, Morbilliform rash appears
- Possible: diarrhea; otitis media; meningoencephalitis.
- Enanthem of soft palate (Nagayama spots).
HHV 7
- Associated with pityriasis rosea.
- Self-limiting skin condition; typically starts with a single large, round, or oval patch.
HHV-8
- Kaposi's sarcoma
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Description
This quiz covers key concepts related to postherpetic neuralgia (PHN) and herpes simplex virus (HSV) infections. It explores characteristics, diagnostic features, treatments, and the epidemiology of HSV-1 and HSV-2. Test your knowledge of both common and less-known aspects of these viral infections.