‫viral rrrrrrrrrrrrrrrrrrrrrrrrrrrrr.pptx

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1. Viral skin Infections

2. - Viruses are small particles of genetic material (either DNA or RNA) that are surrounded by a protein coat called the capsid , some viruses have a fatty envelop covering . - They depend on hosts they infect for their survival (obligate intracellular parasites ).

3. DNA virus : Double stranded DNA : 1- Papova virus : papilloma virus 2-human herpes virus (HHVS): *HHV-1 ( hepes simplex 1) *HHV-2(herpes simplex 2) *VZV(HHV-3) *EBV (HHV-4) *CMC(HHV-5) *H.virus6(HHV-6 ) Roseola infantum . * H.virus 7(HHV.7) * H.virus 8 (HHV-8) associated with Kaposis sarcoma 3-Pox virus : orf – M . Contagiosum

4. RNA Virus : Negative double stranded RNA: 1- para myxo virus – measles . 2-Retro virus – HIV1 and 2. All share a features of causing a primary infection to be followed with life long latency in various tissues according to their tropism to be intermittently shed from those areas .

5. Hepes Simplex One of the common infection , acute self –limiting . Tow types: HSV1 associated with orofacial infection. HSV2 associated with genital infection.

6. Pathophysiology : - Inetial infection: HSV enters via small defect in skin or mucosa and starts to replicate locally in the epidermis , then it spread to sensory ganglion . After resolution of the primary infection the virus remains latent in the sensory ganglion near the spinal cord . -Recurrent infection: reactivation of virus by some stimuli such as UV light , trauma lead seeding of the virus into area served by sensory ganglia and to recurrences .

7. Epidemiology : HSV1 occur mainly in infants and young children . HSV2 infection occur mainly after puberty and are sexually transmitted . Patients below the age of 20 years herpetic withlow due to HSV1, more than 20 years due to HSV2. H . Labials due to HSV1 (80-90%) , HSV2 (10-20%) , urogenital HSV2(70-90%) , HSV1(10-30%). Neonatal HSV2(70%) , HSV1(30%)

8. Incubation period for primary infection 2-20 days (average 7 days) Precipitating Factors for recurrent : UV radiation , menstruation , minor trauma , fever , common cold and stress . Mode of transmission : skin –skin skin - mucosa mucosa – skin

9. Clinical varities : 1- orofacial herpes simplex (herpetic gingivostomatitis ): most cases occur in children 1-5 years . Incubation period 4-5 days . Lesion begains with fever , malaise , there are vesicles as white plaques on the tongue, pharynx , palate , and buccal mucosa . Which followed by ulcers . There is regional L. nodes enlargment with tenderness . Drinking and eating is very painful and the breath is foul . Recurrent orofacial(herpes labialis ) known as cold sores or fever blisters

10. 2) Genital HS infection: occur as clusters of inflammatory papules and vesicles . Which leading to small painful ulcers , bilateral enlarged lymph nodes . Patient has dysuria , urine retention , vaginal and uretheral discharge. In males lesions occur on the glans penis or penile shaft . In females on vulva , perineum , vagina , or cervix . Haeling after 2 -3 weeks . 3) Herpetic whitlow . 4)Herpes gladiatorum . 5)Herpetic keratoconjuctivitis . 6)Recurrent HSV infection is the most common precipitating event in cases of recurrent erythema multiform.

11. 7)Eczema herpeticum ( kaposivaricelliform ) : wide spread HSV cutaneous infection on abnormal skin occurs most commonly in atopic dermatitis and is Ch.Ch . By wide spread vesicles and erosions . It may occure as a primary or recurrent infection , associated with fever , malais , irritability and lymphadenopathy . Also occur in Darier’s disease , thermal burns , pemphigus vulgaris , bullous pemphigoid , and cutaneous T-cell lymphoma.

12. 8)Neonatal HSV infection : the majority of infection are caused by HSV-2 , HSV-1 is more virulent in the newborn . Risk of transmission to a neonates is highest in women who develop primary herpes in the third trimester . The risk of infection to the infant delivered vaginally when the mother has primary infection (genital) is 50% so cesarean section and antiviral therapy for newborn .

13. Eczema herpeticum Neonatal HSV infection

14. Complications: -Secondary bacterial infection . -eczema herpeticum . -cutaneous or systemic dissemination in immuno - compromised patient . -erythema multiform . -herpes encephalitis . D.D: oral 1- apthous stomatitis . 2- hand – foot – and mouth disease . 3-sever candidiasis . 4-P.Vulgaris . 5-Bechcet’s disease. D.D: genital : All genital ulcers .

15. Diagnosis : *History and clinical examination . * Tzanck smear . * culture . *PCR *ELISA *Electron microscope . Treatment : 1- preventive measures . 2-topical antiviral : Penciclovir 1%cream for H.S labialis . Acyclovir 5% cream. calamine lotion locally . zinc sulphat (Soaks) , 0.025 – 0.05 % in water to the site 2-4 times per month to prevent recurrent .

16. 3- oral antiviral : Acyclovir ( zovirax ) 200 mg orally five times a day for 7-10 day . Valacyclovir 1000 mg orally wo times a day . If patient have more than 6 recurrences yearly consider Acyclovir 200 – 400 mg bid or valvacyclovir 1000mg p.o daily for one year .

17. Varicella zoster (VZV) infection: Primary VZV infection result in chicken pox ( Varicella ), reactivation of VZV result in herpes zoster(shingles) or girdle . Varicella (chicken pox): It is acute highly contageous self limiting disease ch.ch by an exanthematous vesicular rash . It is mild in children but may be very serious in adults and immuno compromised patients . Mode of transmission :- 1-air born . 2-direct contact. Patients are infectious 2 days prior to the onset of the vesicular rash until all vesicles are crusted. Incubation period : 10 -23 days.

18. C/P: after a day or two of fever , malaise and headache , the rash start as erythematous macules – papules – vesicles which is itchy and rupture easily – pustules – crusts. The rash begains on face , scalp but it is more numerous on the trunk . Crusts fall off leaving shallow pink depression , scaring occur when the lesion super infected with bacteria .lesions also can be found on the mucosa of pharynx , nose and vagina.

19. Complications : 1- secondary bacterial infection . 2- Reye syndrome : fetal encephalopathy in association with varicella . 3- in pregnancy maternal varicella in the first trimester of pregnancy: congenital varicella syndrome which ch.ch by : limb hypoplasia – ocular defect with zosteriform cutaneous scarring . If the mother has varicella within 4 days before to 2 days after term the baby will has sever varicella with mortality rate up to 30% . Diagnosis : clinically - Tzanck smear – immunofluorescent – PCR.

20. Treatment : rest + analgesics . Symptomatic treatment with calamine lotion with antihistaminics for itching . Topical or systemic antibiotics for secondary bacterial infections . Antiviral therapy given early :* Acyclovir ( Zovirax ) 800 mg 4 times daily for 5 days . * Varicella zoster immunoglobulin (VZIG) . *live attenuated varicella virus vaccine ( Varivax ) is available . *pregnant women : VZ immunoglobulin + antiviral therapy , Vaccine given after delivery .

21. Herpes zoster(Shingles ): it is reactivation of VZV , acute localized dermatomal infection occur more often in elderay patients over 50% . Pathogenesis : Following the initial varicella infection, vzv persists life-long in the sensory ganglia of the spinal cord and cranial nerves, when reactivated, the virus travels down the sensory nerves resulting in the dermatomal pain and skin lesions. clinical picture : Distinct in 3 stages : 1- prodromal stage or pre-eruptive phase : pain , parasthesia . Pain as stubbing ,burning , there is headache ,malaise . Without skin lesions. 2- active infection or acute eruptive phase : eruption of papules rapidly becoming vesicular and then pustular , crust formation days to2 to 3 weeks . The rash is unilateral .

22. 3- chronic pain ( PHN ) persisting after the lesions have healed . Necrotic and ganrenous lesions sometimes occur so H.Z may heal with scare formation . Site of predilection : thoracic > 50% , trigeminal 10-20% , lumbusacular and cervical 10 -20% . *nerve involvement can occur with out cutaneous zoster ( zoster sine herpete ). Mucous membane : vesicles and erosions occur depending on dermatome involved .

23. Complications: 1- post- herepetic neuralgia. 2- secondary bacterial infection . 3- scare formation , post inflammatory hyper or hypo pigmentation . 4- ocular involvement : when first branch of trigeminal nerve( ophthalemic nerve ) involved , patient had keratitis , corneal erosions , conjunctivitis , optic neuritis , sec. glucoma , double vision with headache and vomiting . Vesicles on the tip of the nose (Hutchinson’s sign) indicate nasociliary nerve involvement and greater likehood of eye involvement .

24. Complications: 5- Ramsay Hunt. Syndrome : involvement of both 7 th and 8 th cranial nerves leading to facial paralysis with herpetic vesicles of the external ear or tympanic membrane with vertigo and hearing lose with painful vesicles on palate and, tonge . * Zoster in pregnancy no serious problem . *disseminated H.Z in immunocompromised . Diagnosis : clinically – Tzanck smear . D.D : zosteriform HSV – contact dematitis – erysipeals – bullous impetigo .

25. Therapy : rest+ analgesia – local calamine lotion Oral in sever infection and immunosuppressed patients and must started within 48 hrs. of presence of vesicles . Acyclovir 800mg .5 times per day for 5-7days . * Valvacyclovir 1000mg . 3 times per day for 7 days . *Famciclovir 250 0r 500mg 3 times per day for 7 days . * Foscarnet in cases of Acyclovir resistant .

26. Therapy : . *chronic stage PHN : Analgesics in sever pain Gabapentin 300mg . 3 times per day . *Tricyclic antidepressants such as Doxepin 10 -100 mg at bed time . *Capsaicin cream every 4 hrs . * Topical anaesthetic such as EMLA or 5% lidocaine . * opthalmic H.Z : opthalmic consultation . *oral steroid :in opth . HZ and can be given early in the course of HZ to reliefs pain in older patients .

27. This treatment is likely to prevent PHN but this has not been proved yet Measles ( Rubeola ) : it is a highly contagious infection caused by measles virus which is RNA virus of the genus morbili virus within the family Paramyxoviridae . Mode of transmission : air born through cough and sneezes . And contact with saliva and nasal secretion. People are infectious to others from 4 days before to 4 days after the start of the rash . They usually don’t get the disease more than once . Signs and symptoms : After an incubation period of about 10 days the prodromal symptoms of fever , malaise and upper respiratory Catarrh as cough , coryza , conjunctivitis (red eyes ) and photo phobia .

28. The exantheme develop on the fourth day on forehead and behind the ears then spread within 24 hrs to the rest of the face , the trunk and limbs , the rash is maculopapular it is fade from the sixth to the tenth day to leave brownish, fine desquamation . Complications: Occur in young children chronically ill and malenurshied patients : pneumonia- bronchitis , otitis media. the most serious complication is encephalitis . From the second day the pathognomic exnanthem Koplik’s spots are usually present on the buccal mucous membrane opposite the premolar teeth (bluish white spots with bright red areolae ) .

29. Diagnosis : history , URT symptoms as cough and Koplik’s sign . Treatment : symptomatic as iboprofen for fever , antibiotics for Sec.infection . Vitamin A 200,000IU to prevent blidness . Meseals , Mumpus , Rubeola (MMR) vaccine given in 9months and 18 months with vit.A .

30. Molloscum contagiousem : It is highly contagious viral infection that affect children and adults . Etiology : poxvirus .(MCV1 causes most infections ) and MCV2. Epidemiology : Atopic dermatitis – immundefects – immunosuppression – HIV – AIDS patients Transmission : skin to skin contact sexual transmission and transmission via fomites . And also spread by shaving . In some individuals appear of new lesion by autoinculation or seeding . Incubation period : 4-8 weeks with a range extending out to 6 months .

31. Incubation period : 4-8 weeks with a range extending out to 6 months . Clinical picture : skin colored 1-5 mm pearly , shining multiple umbilicated papules or nodules arranged in groups or linear fashion ( Kobner phenomenon ), distributed on face , neck , eyelids , axillae and extremitis in children , in adults in genital regions . In patients with HIV/AIDS giant M. contagiousem reaching 3-5 cm in size . D.D: flat warts , condylomata accuminata , syringoma , keratoacanthoma , S.C.C and B.C.C .

32. . Diagnosis : clinical picture and histology . Treatment : avoid skin to skin contact Solitary lesion can be destroyed with curettage or sharp tweezers . Cryosurgery . In Immunocompetent children , the lesion can resolve spontaneously in 6-9months . But wide spread lesion removed by curettage . Liquid phenol (dilute) . Local tretinoin .

33. Human papilloma virus : Grouped of closely related DNA virus . There are more than 150 types of HPV has been identified . Epidemiology : children are very commonly infected . Can be transferred from site to site on host (finger to mouth ) or from individual to individual ( condylomata accuminata ) . They manifested as minute papules to large plaques , lesions may become confluent forming a mosaic . The extent of lesions determined by the immune status of the host. Transmission : skin to skin contact . Minor trauma with breaks in stratum corneum . Incubation period : long because the virus replicate slowly .

34. Verruca vulgaris (common warts): warts are a hyperplastic tumor induced by HPV . Clinical picture : firm papules with rough horny surface , size from 1 – 10 mm , hyperkeratotic Ch.Ch . By loss of skin markings and intra lesional hemorrhagic dots . Common site acral (on back of hands , fingers , feet ) or any where , it is symptomless . Diagnosis : clinically ( Punctate bleeding when pared) Histopathology.

35. D/D: Mollosum contagiousm in children . Actinic keratosis , seb.keratosis , and keratoacanthoma in adults . Treatment : spontaneous disappear in months or a few years, so not need aggressive treatment . For small lesions 10 -20% salicylic acid and lactic acid in collodion . For large lesions 40% salicylic plaster . Cryosurgery (liquid nitrogen ) . Electrosurgery : more effective than cryosurgery but with greater chance of scarring .

36. Planter warts ( verruca plantaris ): rough solitary keratotic surface studded with multiple black dots . Often painful , tumor of soles , on pressure point as heal or meta- tarsl areas . Clinical picture : irregular papules with central loss of skin markings , form plaque with hyperkeratotic rough surface. wide spread planter warts called mosaic warts. Diagnosis: clinically : punctate hemorrhage , tendrness .

37. . D/D: 1- corn: located at site of pressure on bony prominence , no punctate hemorrhage . 2-Callus . Treatment : 40% salicylic acid plaster for 1 week . Then apply salicylic acid , lactic acid in collodion . Cryotherapy – electrosurgery – laser .

38. Plane warts (flat wart) : it is a small, flat , slightly elevated papules , skin color or light brown , round from 1-5mm in diameter . Most common on face , dorsa of hands . Spread by autoinoculation , on face of men by shaving ( kobner phenomenon) . Mostly affected children , young adults . Diagnosis: clinically. D/D: on face : syringomas , xanthelasma , Milia , M.contagiousm . Treatment : topical retenoids . Cryotherapy - imiquimod cream - laser

39. Condyloma accuminata (genital warts): It is sexually transmitted HPV of genital and perianal . It is asymptomatic. Associated with HPV strains 6 and 11. Incubation period : 4 weeks to 6months . It is an exophytic (cauliflower like ) papules , nodules , tinea white which rapidly spread and enlarge . Bleeding easly , soft ,pink, multiple on moist surface. Growth enhanced during pregnancy and if there is infection .

40. Diagnostic approach : always examine sexual partners and exclude other STDs , in women must exam cervix to exclude infection in it . D/D: condylomata lata ( sec.syphilis ). Treatment : 1) podophyllotoxin 0.5% solution . Podophyllin tincture 5-20%apply by physician 1 – 2 per week until clear . 3)Topical 5-fluorouracil . 4) Imiquimod 5%cream.