COMMON VIRAL INFECTIONS. Dr D. Tenea Department of Dermatology University of Pretoria

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1 COMMON VIRAL INFECTIONS Dr D. Tenea Department of Dermatology University of Pretoria

2 GENERAL Viral infections of the skin important in immunocompromised Pts. Infection: direct inoculation ( warts ) or spread from other locations Viral exanthems result of generalized infections Four viral families are important for cutaneous disease : - Poxviruses ( Molluscum Contagiosum, vaccinia,variola, orf, milker nodule ) - Picornaviridae ( Coxsackie virus, ECHO virus ) - Herpes viruses ( HSV, VZV,CMV, EBV, HHV-6, -7,-8 ) - Papovaviridae : warts Laboratory techniques : Light microscopy + EME Culture, serology, immune-assays

3 HUMAN PAPILLOMAVIRUS INFECTIONS (Warts=Verrucae ) Small DNA virus replicate in the nucleus papillomas Infect squamous epithelia : skin, oral + genital mucosa, larynx More than 100 types of HPV characterized ( PCR, DNA-sequencing) Papillomas are benign High risk or cancer-associated types of HPV : HPV-11,-16, -18 EDV: HPV-5, -8 Immunocompromised persons ( low CMI ) are at high risk for persistent, severe, progressive HPV infection, resistant to Tx.

4 CLINICAL FEATURES Common warts ( verrucae vulgaris ) Plane warts Palmo-plantar warts : myrmecia and mosaic warts, butcher`s wart Veneral warts : Condylomata accuminatum Mucosal warts : urethra, vagina, anus, conjunctiva, larynx Subclinical and atypical manifestations exist ( venereal verrucae in immunocompromised patients )

5 TREATMENT No effective antiviral treatment exist ( most therapies aim at destruction of visible lesions) Treatment should avoid scarring Recurrences are frequent NEVER EXCISE AND SUTURE WARTS There is no evidence that extensive Tx. has a better outcome Immunomodulatory agents ( Imiquimod) stimulate CMI regression of warts

6 TREATMENT Ctd. Local destructive and cytotoxic therapy : Skin warts : Salicylic acid / Lactic acid / Collodion in Vaseline Cryotherapy for persistent warts Curettage, Cautery, Laser periungual, nasolabial, eyelid Anogenital warts : - Cytotoxic agent : Podophyllotoxin 0,5% solution or 0,15% cream - Physical destruction : Cryotherapy, TCA 80-90% sol., Electrosurgery, Laser vaporization, Scissors excision - Immunomodulatory : Imiquimod 5% cream

7 HERPES VIRUS INFECTIONS Large DNA viruses intranuclear replication Eight HHV : HSV-1 ( lips, mouth, cornea ) HSV-2 ( genital, perianal ) VZV ( varicella, herpes Zoster ) EBV ( = HHV-4 ), CMV ( = HHV-5 ), HHV-6,-7, - 8 ( KS-assoc. ) Ubiquitous pathogens worldwide distribution Transmission : during the periods of viral shedding Virus replicates at site of infection, travel by retrograde axonal flow to the dorsal root ganglia and establish latency until reactivation Produce Primary, Latent, Recurrent infection

8 HERPES VIRUSES Ctd. Primary infection : HSV-1 in infants and HSV-2 at puberty ( no pre-existing antibodies to HSV-1 and -2 ) Recurrent infection : reactivation of HSV after a period of latency ( 50%-- oral herpes, 95% -- genital herpes ) Reactivation of virus : spontaneously or triggered by a stimulus : - stress, UV-light, fever, tissue damage, menstruation, immunosuppression Generalized herpes simplex in immunocompromised patients ( vesicles are diffuse, not grouped )

9 PRIMARY INFECTIONS Subclinical, minimal manifestations in HSV-1 Symptomatic, severe in type 2 Clinical presentations : - Herpetic gingivostomatitis - Keratoconjunctivitis - Herpes genitalis : vulva, vagina, cervix in women / penis glans, perianal in men - Inoculation herpes simplex ( herpetic whitlow on fingertips, periungual HSH-2 )

10 COMPLICATIONS Eczema Herpeticum Herpetic folliculitis of the beard region Pharyngitis, Keratoconjunctivitis Meningism / Encephalitis neonates Postherpetic neuralgia / Neuropathy Disseminated ( systemic ) infection in immunocompromised neonates HSV hepatitis Monoarticular arthritis rare ( widespread disease ) Recurrent Erythema Multiforme ( 65% have Hx.of HSV infection )

11 DIAGNOSIS Clinical Histology of skin biopsy Tzanck smear + viral culture of the vesicle fluid EME ( ultrastructural studies ) Direct Immunofluorescence Serological tests Western blot is both 99% sensitive and specific for detection of HSV-antibodies PCR preferred, rapid Dx. for detection of viral DNA in CSF

12 TREATMENT No treatment in mild forms ( topical antiseptics ) Acyclovir treatment of choice for recurrent infections ( early stage ) Newer antivirals : Valacyclovir ( Zelitrex ), Famciclovir ( Famvir ) Orolabial herpes ( recurrence ) : Zovirax oint. Tid -5 days Genital herpes : First episode Acyclovir 200mg Po 5x days Recurrent Acyclovir 400mg Po tid 5 days Chronic suppression : Acyclovir 400mg Po bid Neonatal immunocompromised : Acyclovir 10mg/kg iv q8 hours-21 days Acyclovir-resistant HSV in HIV+ Pts. Foscarnet : 40mg/kg iv q12hrs-3wk. Antibiotics if secondary infection present

13 HERPES ZOSTER ( Shingles ) Caused by VZV Primary infection results in chicken pox Reactivation of latent virus results in Zoster infection Common in adults and geriatrics + immunocompromised patients Recurrent episodes in young persons --? HIV infection Presentation : grouped vesicles on erythematous base in unilateral, linear, dermatomal distribution Tx. Oral Acyclovir started in the first 72 hours - Topically nothing / dry antiseptic applications - Antibiotics if sec. infection occurs

14 MOLLUSCUM CONTAGIOSUM Exclusively a human disease Poxvirus Common worldwide distribution Contagious ( direct contact, contaminated objects, sexual ) Two peaks of incidence : 2-4 years and adolescence (rare <1yr. ) Incubation period : 14 days 6 months Clinical features : dome shape papules with umbilication (cheesy material ) Distribution of lesions is influenced by the mode of infection

15 Management Destruction of lesions : - Cryotherapy ( repeated every 3 weeks ) - Curettage ( large lesions ) - Expression of content of the papule by squeezing -Laser Topical preparations used to produce an inflammatory response : - Tretinoin % Salicylic acid in collodion base - TCA ( trichlor-acetic acid ) applications - Podophyllotoxin cream / sol. - 5% Imiquimod cream ( Aldara )

HERPES VIRUSES. Large DNA viruses, replication is intranuclear and produce typical intranuclear inclusions.

HERPES VIRUSES. Large DNA viruses, replication is intranuclear and produce typical intranuclear inclusions. Viral infections HERPES VIRUSES Large DNA viruses, replication is intranuclear and produce typical intranuclear inclusions. Typical feature: absence of viral elimination after infection, clinical latency