Clinial manifestation
• Features of the lesion: multiple small
papules, vesicles, clusted together.
Mature lesion: grouped vesicles and / or pustules on an erythematous edematous base
Virus
– Two antigenic types: HSV-1, HSV-2 HSV-1: lesions on the lips, face HSV-2: genital herpes
Lesions anywhere may be caused by either
antigenic type. – Transmission: Intimate contact ( direct inoculation through traumatized skin )
stress, menstruation
Epidemiology
• 85% of adults worldwide are seropositire for HSV-1.
Seroprevalence for HSV-2 is lower, appear at the age of onset of sexual activity.
• Virus culture
Emphasis
• Serologic tests (detection of anti-HSV antibody of the blood) are generally not used in determining whether a skin lesion is due to HSV infection.
Classification of Viral dermatoses
• Poxvirus group
Molluscum contagiosum, milker’s nodules
• Papovavirus group
Warts(common warts, Flat warts,
plantar warts, genital warts)
Viral Dermatoses
Department of Dermatology
Xiao Sheng-Xiang
General Description
• Definition
Viral dermatoses are the cutaneous diseases resulting from viral infections.
Classification of Viral dermatoses
• Herpesvirus group
– Herpes simplesx
– Varicella ( Chickenpox )
– Herpes Zoster
– Roseala Infantum ( Sixth disease)
– Kaposi’s sarcoma
• Detection of virus antigen of the lesion
Materials:vesicular fluid ,cells from the base of skin lesion
Methods: direct fluorescent antibody test immunoperoxidase tchniques
• Common site for lesions: face, lips, mouth,
neck, anogenital area
• Heal within 1-2 week • Laboratory Test
Tzanck smear: take a smear of cells from the base of the skin lesion spread the cells on a glass slide stain with wright or Giemsa Stain look for multinucleated giant cells Non specific: HSV VZV Accuracy rate: 60~90% False positive rate: 3~12%
• Picornavirus group (enteroviruses)
Hand-fooot –mouth disease (coxackie virus)
• Retroviruses
AIDS
Herpes Simplex
Etiology
• Herpes Simplex Virus ( HSV ): DNA
– Primary infection and recurrent infection Primary infection: first infection After primary infection neuronal cells in ganglion virus migrates to the latent infection replicate
latent virus to reactivate by triggering factors
virus particles move on the nerve in the epithelial cells recurrent infection
– Triggering factors: fever, trauma, emotional
Classification of Viral dermatoses
• Parvovirus
Erythema infectiosum( fifth disease)
(B19 virus)
• Paramyxovirus group
Measles, rubella
Classification of Viral dermatoses
USA: ~23% of adults are infected with HSV-2
Developing countries: 60~95% of infection rates of HSV-2 • Incubative or subclinical infection: 90% of all infected