Vesicular Rash Presented by: Dr.Abeer omran Pediatric infectious Diseases Consultant Head Infection Control Division

Vesicles: are small, fluid-filled sacs that can appear on skin Vesicles: are small, fluid-filled sacs that can appear on skin. A number of different health conditions can cause vesicles, from allergic reactions and dermatitis to chickenpox and herpes. typically about five to 10 millimeters in diameter. If they have a diameter of at least half a centimeter, they’re known as bullae.

1-Herpes simplex Virus: Herpesvirus Family. Double-stranded DNA genome. categorized into 2 types: 1- herpes simplex virus type 1 (HSV-1) 2- herpes simplex virus type 2 (HSV-2).

Mode of Transmission: HSV-1 is mainly transmitted by oral-to-oral contact to cause oral herpes (which can include symptoms known as “cold sores”), but can also cause genital herpes. the greatest risk of transmission is when there are active sores. HSV-2 is a sexually transmitted infection that causes genital herpes. Both HSV-1 and HSV-2 infections are lifelong.

Viral infection Primary infection: Occurs in individuals who have not been infected previously with either HSV-1 or HSV-2. Reactivation ( recurrence): Occurs in individuals previously infected with 1 type of HSV (e.g., HSV-1), can be symptomatic or asymptomatic. Latent Phase: Inactive phase of the virus, no replication ( no clinical symptom )

Clinical manifestation

Herpetic gingivostomatitis occurs in children aged 6 months to 5 years. The incubation period is 3-6 days. Abrupt onset, High temperature , Anorexia and listlessness, Gingivitis (This is the most striking feature, with markedly swollen, erythematous, friable gums.), Vesicular lesions, Tender regional lymphadenopathy, Perioral skin involvement due to contamination with infected saliva. Course: Acute herpetic gingivostomatitis lasts 5-7 days, and the symptoms subside in 2 weeks. Viral shedding from the saliva may continue for 3 weeks or more.

Herpes whitlow Herpes whitlow is a term generally applied to HSV infection of fingers or toes. Unlike other recurrent herpes infections, recurrent herpetic whitlows are often as painful as the primary infection Cutaneous HSV infections can be severe or life threatening in patients with disorders of the skin such as eczema (eczema herpeticum), pemphigus, burns.

Ocular herpes Dendritic Ulcer

complications Severe disease In immunocompromised people, such as those with advanced HIV infection, HSV-1 can have more severe symptoms and more frequent recurrences. HSV-1 infection can also lead to more severe complications such as encephalitis or keratitis (eye infection).

Neonatal herpes Neonatal herpes is a rare, but sometimes fatal, condition that can occur when an infant is exposed to HSV in the genital tract during delivery. The risk for neonatal herpes is greatest when a mother acquires HSV infection for the first time in late pregnancy.

Diagnosis: Samples; Blood, vesicular fluid, CSF, eye swab. can be done by: HSV PCR HSV serology ( IgG and IgM) HSV Ag detection by Direct Fluorescent test ( DFA) Viral Culture; done only in special lab. Brain imaging studies in HSV encephalitis generally demonstrate focal localization in the temporal area that is associated with edema and contrast enhancement.

Management : Supportive management ( Fluid, pain medication) Acyclovir, to be started as early as possible, within 72 hr of onset can reduce the severity and duration of the illness Duration of the acyclovir depends on the site of infection

2-Varicella-Zoster Virus Infections Herpesvirus (DNA) Primary infection results in varicella (chickenpox) Reactivation of latent infection results in herpes zoster (shingles) Short survival in environment

Varicella Clinical Features Incubation period 14 to 16 days (range 10 to 21 days) Contagious 24-48 hr before the rash is evident and until vesicles are crusted. The initial exanthem consists of intensely pruritic erythematous macules that evolve through the papular stage to form clear, fluid filled vesicles. Rash generally appears first on head; most concentrated on trunk Mild prodrome for 1 to 2 days (adults) Successive crops over several days with lesions present in several stages of development

Crops of vesicles

Herpes Zoster (Shingles) Reactivation of varicella zoster virus (VZV) Associated with: aging immunosuppression Vesicular rash usually is dermatomal in distribution Begins with burning pain followed by clusters of skin lesions in adults

Varicella Complications Bacterial infection of skin lesions(Staphylococcal and streptococcal ) . Pneumonia (viral or bacterial) Central nervous system manifestations, (cerebellar ataxia, encephalitis).

Groups at Increased Risk of Complications of Varicella Persons older than 15 years Infants younger than 1 year Immunocompromised persons Newborns of women with rash onset within 5 days before to 2 days after delivery

Congenital Varicella Syndrome Results from maternal infection during pregnancy Period of risk may extend through first 20 weeks of pregnancy Low birth weight, hypoplasia of extremity, skin scarring, eye and neurologic abnormalities Risk appears to be very low (less than 2%)

Diagnosis: Laboratory evaluation has not been considered necessary for the diagnosis or management of healthy children with varicella or herpes zoster. Diagnosis is mainly clinical The following tests are done in some condition: Cutaneous lesions ( fluid) - Direct fluorescence assay (DFA) of cells from - Tzanck smear: multinucleated giant cells will be seen under microscope . Blood: - VZV PCR - Varicella serology : IgG and IgM

Tzanck smear multinucleated giant

Treatment Supportive management( fluid, calamine lotion, fever and itching medicine) Acyclovir therapy is not recommended routinely in otherwise healthy child. It is recommended in: Pregnant women Individuals >13 yr of age. Patient with chronic cutaneous or pulmonary disorders. Individuals receiving corticosteroid therapy. Individuals receiving long-term salicylate therapy. Possibly secondary cases among household contacts. Should be initiated as early as possible, preferably within 24 hr of onset of rash.

Varicella Vaccine live-attenuated viral vaccine, approved for persons 12 months and older. Varicella Vaccine Immunogenicity and Efficacy: Detectable antibody 97% of children 12 months through 12 years following 1 dose 99% of persons 13 years and older after 2 doses 70% to 90% effective against any varicella disease 90%-100% effective against severe varicella disease

Varicella Vaccine Postexposure Prophylaxis Varicella vaccine is recommended for use in persons without evidence of varicella immunity after exposure to varicella 70%-100% effective if given within 3 days of exposure (possibly up to 5 days) not effective if administered more than 5 days after exposure but will produce immunity if recipient is not infected

Varicella Zoster Immune Globulin Immunocompromised patients Neonates whose mothers have signs and symptoms of varicella around the time of delivery (i.e., 5 days before to 2 days after); Preterm infants born at 28 weeks gestation or later who are exposed during the neonatal period and whose mothers do not have evidence of immunity; Preterm infants born earlier than 28 weeks’ gestation or who weigh 1,000g or less at birth and were exposed during the neonatal period, regardless of maternal history of varicella disease or vaccination; and Pregnant women.