L-4 Cutaneous Manifestations of Viral Infections

Cutaneous Manifestations of Viral Infections

• Recognizing cutaneous manifestations, understanding epidemiology, identifying unique characteristics, and proper diagnosis, treatment, and potential complications of common viral infections are important.
• Common viral infections to recognize cutaneous manifestation for: Measles, Rubella, Varicella, Shingles, Roseola, Erythema infectiosum, Hand, Foot, and Mouth Disease, Molluscum contagiosum, Verruca vulgaris, Herpes labialis, and Infectious mononucleosis.

Measles

• Etiology: Measles virus is an enveloped (-) ssRNA virus belonging to the Morbillivirus genus and Paramyxoviridae family.
• Epidemiology: Measles spreads through infected nasal or throat secretions via coughing or sneezing; Highly contagious with a Ro of 12-18 because it can stay suspended in the air or on infected surfaces for up to 2 hours.
• Pathogenesis: Primary infection site is alveolar macrophages or dendrites of pulmonary epithelium; The virus replicates in the lungs for 2-3 days and spreads to regional lymphoid tissues and then disseminates the virus systemically via infected monocytes.
• Measles phases: Incubation (2 weeks), Prodromal (cough, coryza, conjunctivitis, malaise for 3-4 days), and Exanthem where a diffuse erythematous maculopapular rash known as "morbilliform" lasts about 5-6 days.
• Clinical Manifestations: Prodrome symptoms: high fever, cough, coryza, conjunctivitis, and malaise (3-4 days) and Koplik spots precede the rash.
• Maculopapular Rash: Starts on the scalp and behind the ears, spreads to the trunk and extremities ("centrifugal"), and leaves a diffuse brownish discoloration for weeks.
• Diagnosis: Includes history (exposure), skin inspection for pattern of presentation, RT-PCR of a nasal swab, serology to test for IgM antibodies, and culture.
• Management involves supportive care.
• Prognosis: Self-limited course of 7-10 days; 1/1000 mortality rate; Complications include pneumonia, otitis media, gastroenteritis, and subacute sclerosing panencephalitis (SSPE) 7-10 years post-measles.
• Prevention: MMR vaccine and avoiding aspirin to prevent Reyes Syndrome.

Rubella (German Measles)

• Etiology: Rubella virus is an enveloped, icosahedral capsid, (+) ssRNA virus of Togaviridae family.
• Epidemiology: Rubella occurs worldwide with an incubation period of 12-23 days and a Ro of 1.5-6.5 and is transmitted through airborne/respiratory droplets or direct contact.
• Pathogenesis: Primary target is the respiratory epithelial cells and lymph nodes; initial replication happens in the respiratory tract and then viremic spreads through blood and lymphatics; A diffuse maculopapular rash occurs on the face then spreads to the rest of the body, and to lymphoid tissues.
• Rubella has the ability to cross the placenta and infect developing fetal tissues.
• Lifetime immunity is likely to develop.
• Clinical Manifestation: Diffuse maculopapular rash starts on the face and spreads centrifugally to the body, lasts 3 days, accompanied by low-grade fever, sore throat, cough, runny nose, and posterior auricular/suboccipital lymphadenopathy.
• Rubella during pregnancy can cause stillbirth or spontaneous abortion.
• Congenital Rubella Syndrome: Ocular and heart defects, hearing loss, and other anomalies.
• Diagnosis: H&P, serology (ELISA), and RT-PCR of nasopharyngeal swabs.
• Commonly known as "Three-day Measles".
• Management: Supportive care.
• Children’s progonosis is mostly self-limited.
• Prevention: Trivalent MMR vaccine protects using the live-attenuated version of measles, mumps and rubella.

Varicella

• Etiology: Varicella Zoster Virus (VZV) - enveloped dsDNA virus, Human Herpes Virus Type 3 (HHV-3), Herpesviridae.
• Epidemiology: Person-to-person spread via direct contact with infected secretions from skin lesions or inhalation of infected respiratory droplets; Incubation period is up to 3 weeks and is worldwide.
• Immunocompromised individuals are at greater risk.
• Pathogenesis: VZV enters via respiratory tract and conjunctiva then replicates in nasopharynx and regional lymph nodes; Viremia occurs where lesions crust a few days after the infection and establish latency in neurons.
• Fever and generalized, very pruritic, vesicular ulcerative rash with 250-500 lesions in crops, as well as varying stages of development and resolution.
• Vesicles appear with "dew drops on a rose petal" and begins on the face then spreads to the neck, trunk, and extremities ("centrifugal")
• Diagnosis: H&P; skin inspection; Labs for PCR of fluid from scabs or saliva/buccal swab; DFA direct fluorescent antibody stain, and Tzanck Smear of base of lesion to reveal multinucleated giant cells.
• Varicella is also known as "Chicken pox".
• Management: Supportive care, Acyclovir (oral/IV), Avoid Aspirin to avoid Reye's Syndrome.
• Prognosis: Self-limiting (2-4 weeks), unless complications.
• Complications: Pneumonia, impetigo/cellulitis (Staphylococcus aureus, Streptococcus pyogenes), Encephalitis. Case fatality: high in infants/fetus & Adults. *Shingles appears later in life.
• Prevention: VZV Vaccine. Antibody response (natural/vaccine).

Shingles

• Etiology: Varicella-Zoster virus (VZV); Herpesviridae.
• Epidemiology: Transmitted via direct skin contact or by inhaling infected droplets; Risk factors: elderly and history of childhood varicella.
• Triggers: emotional stress, medications (immunosuppressants), acute or chronic illness, exposure to VZV and/or malignancy.
• Pathogenesis: Decades after primary varicella infection, VZV is dormant/latent in the cranial nerve or dorsal root ganglia after varicella. Reactivates into shingles and grouped into 1-3 sensory dermatomes.
• Shingles occurs from failure of the immune defense system to control latent replication; Upon reactivation, the virus replicates in the neuronal cell bodies, virions shed and carried down the nerve to the skin area innervated by ganglion.
• Pain results from inflammation of the nerves caused by virus; Cutaneous lesions produce VZV-specific T-cell production which produces interferon alfa to resolution of herpes zoster.
• Clinical Manifestations: Very painful vesicular rash in dermatomal distribution, mainly on trunk (often in older patient with childhood history of varicella).
• Acute eruptive phase: Commonly involves the thoracic (53%), cervical (20%), trigeminal (15%), including ophthalmic and lumbosacral (11%) dermatomes.
• Pre-eruptive stage: (48hrs) skin sensations/pain in dermatome that is affected and leads to headaches, malaise, and photophobia.
• Vesicles often rupture, ulcerate and crust over, and patients are most infectious until the lesion drys.
• If chronic infection (4 weeks+), recurrent pain, paresthesias, shock-like sensations, and dysesthesias manifest; shingles oticus (Ramsay Hunt syndrome) and ophthalmic zoster.
• Diagnosis: Clinical H+P and Tzanck smear of lesion can be performed.
• Management: Acyclovir, Valacyclovir, and Famciclovir work to reduce pain and complications.
• Complications: the rash from shingles scabs over and post-herpetic neuralgia may occur long after.
• Prevention: Shingrix herpes zoster vaccine.

Roseola Infantum (Exanthem Subitum)

• Etiology: Human Herpesvirus Type 6 (HHV-6) or Human Herpesvirus Type 7 (HHS-7); DsDNA virus.
• Epidemiology: Highest incidence is in children 6 months to 3 years old, in late Fall/Spring; Transmits through respiratory secretions. Incubation period is 7-15 days.
• Pathogenesis: Febrile phase lasts 3 days, where HHV6 replicates in salivary glands and is secreted as primary source of infection; Rash (Exanthem) erupts after fever subsides. Latency of the virus in lymphocytes and monocytes results in rash once rash phase is beginning.
• Clinical Manifestations: High fever (102-104 F for 3-5 days with no signs of infection; Mild upper respiratory symptoms +/- periorbital edema, rash breaks out as fever subsides).
• Non-pruritic blanching erythematous maculopapular rash is rose-colored, surrounded by white around the trunk, and spreads centripetally.
• Diagnosis: Based on clinical presentation (H&P) and confirmed by IgM and four-fold rise in IgG titer over weeks.
• Supportive treatment with hydration and antipyretics(+/-).
• Prognosis: Is self-limited unless immunocompromised.
• Complications: Rare, but febrile seizures can occur.
• Prevention: No vaccination.

Erythema Infectiosum (Fifth Disease)

• Etiology: Parvovirus B19- Naked, icosahedral capsid, ss DNA.
• Epidemiology: Occurs in school-aged children and in elderly, it is moderately contagious with Ro=6-8
• Pathogenesis: Through viremic and is contagious, Parvovirus replicates in committed erythroid precursor cells in the bone marrow, resulting in erythroid aplasia and complement-mediated vasculitis.
• Clinical Manifestations: In children prodrome lasts 7-10 day with low-grade fever, malaise, cough, headache, coryza, nausea/vomiting/diarrhea.
• Exanthem: Coalescent erythematous maculopapular rash on face ("slapped cheeks" appearance) lasting 1-4 days + circumoral pallor + reticulated (lacy) erthematous rash.
• the trunk and extemities lasts 4-9 days and may wane for a few weeks while sparingpalmar/plantar areas.
• Diagnosis: Clinical H+P, serology (IgM and IgG antibodies).
• Management: Supportive with aplastic anemia, may treat with IVIG.
• Complciations: Aplastic anemia and hydrops fetalis may occur due to infected pregnant mother and can cause aplastic crisis if sick patient has sickle cell.
• Prevention: Keep infected children away from pregnant females.

Hand, Foot, and Mouth Disease

• Etiology: Coxsackievirus, Types A & B, (+) ssRNA; Naked, icosahedral capsid, Picornaviridae.
• Epidemiology: Worldwide, incubation of 3-5 days, transmitted through direct contact and/or feal-oral route.
• Pathogenesis: Coxsackievirus replicates is oropharynx and intestinal tract Lymph nodes > bloodstream > CNS➔ meninges-> motor neurons where it attacks epithelial cells, muscle cells and CNS.
• Virulence factor: cytolytic enzymes damage host cells.
• Clinical Manifestations: Moderate fever and inflamed exudative pharynx (tender vesicles in oropharynx. May by aphthous/ulcerative May cause vesicular rash on palms of hands and soles of feet and pleuritic chest pain.
• Diagnosis: Clinical examination and may viral culture and rT-PCR (spinal fluid).
• Management: Supportive care.
• Complications: Herpangina aphthous stomatitis, myocarditis and pleurodynia.
• Prevention: Proper hygiene, avoid close contact.

Molluscum Contagiosum

• Etiology: Pox virus, ds DNA virus- Enveloped, complex, ovoid to brick-shaped Poxviridae.
• Epidemiology: Found worldwide, mainly in young children <10 years of age with immunocompromised features with incubation from 1 week-6 months by contact, sexual transmission.
• Pathogenesis: Pox virus enters by microtraumas where it replicates and forms molluscum bodies in the epidermis with abundant large granular eosinophilic cytoplasmic inclusion accumulated virions.Viral proteins interfere with.
• Clinical Manifestations: Small, flesh-colored, dome-shaped umbilicated papules skin. The Ro is 2-5.
• Diagnosis: labs and viral culture.
• Manifestations: water warts. Managements Self limiting Cryotherapy. laser and cream.
• Prevention: proper washes and covering lesion to prevent spread.

Verruca Vulgaris (Common Warts)

• Etiology: Human Papilloma Virus (HPV); ds-DNA non-enveloped virus: Mostly HPV6, 11, 16, 18.
• Transmission and Epidemiology: Occurs worldwide with high prevalance by skin and sexual.
• Pathogenesis: through skin, mucous and exposes in basal layer and modifies hormone levels which leads to abnormal levels;
• Clincial: Rough round populars with irregular surface disrupt the surface and often isolate anwyher on body or plantars, filiform laboratory there is no test.
• Management: Cutage and electercautery and liquid Salicylic .
• Complicated: vagal cancer in throat and genital Treatment Choices: Curettage, electrocaultery/cryotherapy and topical immunomodulator.
• Prevention: Avoid shearing personel item.

Herpes Labialis (Cold Sores; Fever Blisters)

• Etiology: Herpes Simplex Virus 1 (HSV-1); ds DNA genome; enveloped icosahedral capsid, herpesviridae.
• Epidemiology: Incubation is 2 to 12 with respitory or through salica.
• Pathogeneis: Through the replication or tissue Painful vesicles, cells and in immunity.
• Cytopathic effects = structural changes resulting in host; Multi- nucleated, Primary target and latent Immunity is essential in limiting.
• Clinical manifestation: with pain.
• Clinical Manifestation: Erythema, papules, vesicles and painful is in fluid/cells
• Complication: flu-like symptoms, painful Diagnosis: respiratory Fluid micro Labral herpes is in area. Manangent
• Prevention: Anti virals Medications. and hygiene
• Prevention: Avoidy physical contact.

Infectious Mononucleosis

• Etiology: Epstein-Barr Virus (EBV); ds-DNA virus; Herpesviridae; Human Herpes Virus Type 4 (HHV 4).
• Epidemiology: Transmission = skin contact from salvia. Low communicability (requires repeated contact).
• Pathogenesis: Is B cells can oral No CPE. Manifestations: Fever, and erythrmous skin is inactive.
• Clinical Manifestations: Classic: Fever, Fatigue. Skin is inactive
• Clinical: Mono antibody not sensitive in week, no treatment .self limiting ,
• Complications: Hepatitis ,lymph
• Prevention avoid vaccine and share drink with brush.

What is the Diagnosis?

• Case #1: Rubella is a low-grade fever with URI symptoms and a 3-day diffuse maculopapular rash ("centrifugal distribution") and is moderately contagious where a rash appears on Post/aur/Sub lymphadenopathy. It has a long incubation period, a (-)ss RNA virus; ELISA/RT-PCR where has vaccine and can cause perinatal infection and congenital anomalies.
• Case #2: Shingles cases present with a painful vesicular rash, commonly dermatomal with disabling pain and is common with the elderly as well as those with Post-rash nueralgias with Tzanck smear as the lab test anddsDNA virus and a vaccine available.
• Case #3: Roseola infantum cases present prodrome of 3 days with infection and fevers with pruritic rash with centrifugal with rose colored, and is with fever, and its ds DNA with D titer as not and seizure.
• Case #4: Erythema infectiosum presents a coalescent rash will start with"cheeks" pallor The produces and Contagious ( =)- with marrow
• Case #5: Verruca vulgaris presnets round papules and distruptive anywhwere as periplantar for ds DNA and topical.
• Case #6: Hand, Foot, and Mouth disease presents Exudative pharyngitis for vA.
• Case #7: Herpes labialis presnets painful vesicles on. With treat and to in sensory.
• Case #8: Infectious Mononucleosis with fatigue .
• Case #9: Molluscum contagiosum has small, flesh, prutitic- on DS common in can be
• Case #10: Measles cough diffiuse the ss SSPE.
• Case #11: Varicella of the rose" on . of of dsDNA noues- treatment

Additional Questions

• Etiologic agents of the following diseases:
  • Roseola infantum: Human Herpesvirus 6 (HHV-6) or 7 (HHV-7).
  • Infectious mononucleosis: Epstein-Barr Virus (EBV).
  • Erythema infectiosum: Parvovirus B19.
  • Verruca vulgaris: Human Papilloma Virus (HPV).
  • Varicella: Varicella-Zoster Virus (VZV).
  • Molluscum contagiosum: Poxvirus.
  • Measles: Measles virus (Morbillivirus).
  • Rubella: Rubella virus.
  • Shingles: Varicella-Zoster Virus (VZV).
  • Hand, Foot, and Mouth disease: Coxsackievirus A & B.
• The classic prodrome of measles: High Fever, cough, coryza, conjunctivitis, malaise
• Viral exanthems with post-auricular/suboccipital lymphadenopathy: Rubella.
• Viral exanthem that presents as "dew drops on a rose petal": Varicella.
• Typical finding on Tzanck smear of herpes lesion: Multinucleated giant cells.
• Treatment of choice for varicella: Acyclovir
• Viral exanthem with complication of SSPE: Measles.
• Another name for shingles oticus: Ramsay Hunt syndrome.
• Malignancies commonly associated with EBV: Lymphomas, Nasopharyngeal Cancer
• Serotypes of HPV associated with cervical cancer: HPV 16 and HPV 18.