1. Viral Dermatoses Department of Dermatology Xiao Sheng-Xiang

2. General Description Definition Viral dermatoses are the cutaneous
diseases resulting from viral infections.

3. Classification of Viral dermatoses
Herpesvirus group
Herpes simplesx
Varicella ( Chickenpox )
Herpes Zoster
Roseala Infantum ( Sixth disease)
Kaposi’s sarcoma

4. Classification of Viral dermatoses
Poxvirus group
Molluscum contagiosum, milker’s nodules
Papovavirus group
Warts(common warts, Flat warts,
plantar warts, genital warts)

5. Classification of Viral dermatoses
Parvovirus
Erythema infectiosum( fifth disease)
(B19 virus)
Paramyxovirus group
Measles, rubella

6. Classification of Viral dermatoses
Picornavirus group (enteroviruses)
Hand-fooot –mouth disease (coxackie virus)
Retroviruses
AIDS

7. Herpes Simplex

8. Etiology Herpes Simplex Virus ( HSV ): DNA 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 )

9. Primary infection and recurrent infection
Primary infection: first infection
After primary infection virus migrates to the neuronal cells in ganglion latent infection latent virus to reactivate by triggering factors virus particles move on the nerve replicate in the epithelial cells recurrent infection
Triggering factors: fever, trauma, emotional stress, menstruation

10. 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.
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

11. Clinial manifestation
Features of the lesion: multiple small papules, vesicles, clusted together.
Mature lesion: grouped vesicles and / or pustules on an erythematous edematous base
Common site for lesions: face, lips, mouth, neck, anogenital area
Heal within 1-2 weeks

19. Diagnosis Clinical Diagnosis 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%

20. Detection of virus antigen of the lesion
Materials:vesicular fluid ,cells from the base of skin lesion
Methods: direct fluorescent antibody test immunoperoxidase tchniques
Virus culture

21. 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.
A positive result to a serologic test indicates only that the individual is infected with that virus, not that the viral infection is the cause of the current lesion.

22. Threatment Therapeutic principle To shorten disease duration
To prevent bacterial infection
To prevent recurrence

23. Threatment Anti-HSV therapy Primary infection:
Acyclovir: 0.2g, five times/day×7-10days
Valaciclovir: 0.3g, bid ×7-10days
Famcyclovir: 0.25g, tid ×7-10days
Recurrent infection: treatment duration 5 days

24. Threatment Severe recurrent cases acyclovir 04g bid
valacyclovir g qid
famcyclovir g bid 4M to 1Y

25. Threatment Other antiviral agents like IFN- or may be applied
Topical therapy
1% pencyclonir cream,
1% acyclovir cream,
topical antibiotics

26. Varicella & herpes zoster

27. Etiology Varicela-zoster virus (VZV): human herpes virus-type 3
Tranmmission:
direct contact
respiratory route
A very communicable disease

28. Primary infection:
varicella or subclinical infection
Virus reactivation:
herpes zoster
Cellular immunity and herpes zoster
90% cases of varicela ＜10 years of age

29. Clinical manifestation
Varicella
Skin lesion: macules →vesicles (within 24hs) →successive fresh vesicles (within 4 days)
Hemorrhagic, necrotic or bullous lesion

34. The site of lesions:
trunck, face, oral mucosa
Other symptoms:
fever (moderate )
pruritus, secondary infection

35. Herpes zoster Features of the lesions:
Occurs unilateraly within the distribution of a cranial or spinal sensory nerve
Skin lesions: papules, plaques of erythema, blisters in the dermatome
Pain associated with herpes zoster
Disease duration: 2-3weeks in the younger,
6 weeks or more in the elderly

43. Diagnosis , differential diagnosis
Herpes zoster and herpes simplex
In the early stages of herpes zoster, if the number of lesions of zoster is limited, it can be relatively indistinguishable from herpes simplex.
Herpes zoster: more painfull, progress to involve more area over 24hs

44. Treatment Varicella Antiviral therapy
acyclovir 20mg/kg/d ×5days ,not routinly recommended
Topical antipruritic lotions

45. Herpes Zoster General therapy Restrict physical activities
Local applications of heat
Topical anesthetics, antipruritic lotion, topical antiviral agents
Vesicular stage: cool compress

46. Antiviral therapy: reduce the duration of pain
Start preferably within the first 3 or 4 days
Severe cases: intravenous therapy (acyclovir, 5mg/kg, tid)
Refrence doses
Acyclovir 0.8g 5times/day ×7 days
Valaciclovir 1.0g tid ×7 days
Famciclovir 0.5g tid ×7 days

47. Zoster associated pain
Drug therapy:
simple analgesics like aspirin
Tricyclic antidepresants like amitriptyline
anticonvulsants like carbamarepine
Local anesthetics: 10% lidocain gel or patches
Nerve blocks

48. Bacterial Dermatoses Impetigo

49. Etiology 50~70% of cases: staphylococcus aurens
The reminder: streptococcus or a combination
Occur frequently in children in hot, humid weather
Sources of infection for children: pets, dirty fingernails, crowded housing areas

50. Clinical manifestation
Nonbullous impetigo
Begins with 2-mm erythematous macules
vesicles or bullae seropurulent discharge golden yellow crusts
spread by scratching and autoinoculation

53. Bullous impetigo
occurs in new-born infants (4th-5th day of life)
bullae in the face, hand and other sites
later weakness, fever or subnormal temperature
Diarrhea
Bacteremia, pneumonia or meningitis

55. Diagnosis Clinical diagnosis
Bacterial examination: gram stain or culture

56. Treatment Topical agents Rivanol ( Compound Ethacridine Solution)
2% mupirocin ointment
other topical antibiotic agents

57. Systemic agents Antibiotics
Semisynthetic penicillin (penicillinase-resistant) like dicioxacillin
Cephalosporin
Erythromycine, azithromycine
Clindamycine

58. Staphylococcal scalded skin syndrome (SSSS)
A generalized, confluent, superficially exfoliative bacterial disease, occurring in neonated and children

59. Etiology Group 2 staphylococcus aureus, most commonly phage type 71
Epidermolytic exotoxin
Infection sites: pharynx, nose, ear, conjunctive, septicemia, cutaneous infection

60. Clinical manifestations
Abrupt fever
Skin tenderness
Diffuse erythema in the neck, groin, axillae
Generalized exfoliation within hours to days, sheets of epidermis separating
Positive nikolsky sign
Healing within 10 days

61. Diagnosis Treatment Laboratory findings
Leukocyte count,neutrophil proportion
Bacterial culture: mucous membranes ,
skin
Treatment
Antibiotics
Fluid therapy and general supporative measures

62. Thanks!