SKIN & SOFT TISSUE INFECTIONS Rasha A. Nasr Prof. of Med. Microbiology & Immunology, Faculty of Medicine, ASU

Transcription

1 Click to edit Master title style Edit Master text styles SKIN & SOFT TISSUE INFECTIONS Rasha A. Nasr Prof. of Med. Microbiology & Immunology, Faculty of Medicine, ASU

2 Mucocutaneous lesions caused by viruses Viruses reach the skin through: Direct inoculation e.g. HPV Blood The virus enters body through RT viremia skin e.g. measles, rubella, VZV.

3 The outcome of viral infection of skin is either Vesicular skin lesions lesions are sites of viral growth & are infectious Maculopapular lesions lesions are non-infectious & immunologically mediated Tumors

4 Vesicular Maculopapular Tumors

5 HSV Coxsackie A virus Viruses causing VESICULAR LESIONS VZV Small pox virus

6 Herpes simplex viruses Click to edit Master title style Edit Master Two distinct text styles HSVs; type 1 & 2 distinguished from each other antigenically Structurally & morphologically indistinguishable.

7 Click to edit Master title style Edit Master HSVs are text extremely styles widespread & cause a wide variety of clinical symptoms. The Third basic level lesion is intraepithelial vesicle. Herpes simplex viruses

8 They establish latent infections in nerve cells; reactivations are common. They can be reactivated by????

9 Pathogenesis Transmission: HSV-1: contact with vesicular lesions or infected saliva. HSV-2: sexual contact The virus enters body via minute abrasions may be asymptomatic or initiate lytic cycle of infected cells leading to vesicular skin lesions Recovery occurs by abs & CMI

10 Genital infection Gingivostomatitis Clinical Manifestations Conjunctivitis keratitis H. gladiatorum H. whitlow H. labialis

11 Ulcerative gingivostomatitis & Pharyngitis

12 Herpes Labialis (fever blisters or cold sores)

13 Conjunctivitis & keratitis

14 Dendritic Ulcer

15 Herpetic whitlow

16 Herpetic gladiatorum

17 Serious complications include: Click to edit Master title style Eczema herpeticum Edit Master text styles Encephalitis Neonatal infection Reactivation in immunocompromised leading to severe disease

18 Laboratory diagnosis of HSVs infection Click to edit Master title style Edit Direct Master text demonstration styles of virus from lesions at Second affected level site Virus isolation

19 Click to edit Master title style Direct demonstration Edit Master LM: text styles Second o Multinucleated level giant cells (Tzanck smear) o Intranuclear IB (cowdry bodies)

20 Click Direct to edit demonstration Master title style EM Edit Master text styles

21 Direct demonstration of virus Click to edit Master title style DIF Edit Master text styles HSV-infected epithelial cell from skin lesion PCR

22 HSV Isolation Click to edit Master title style Edit Master text styles CPE Intranuclear IB

23 Treatment Click to edit Master title style Edit Master Acyclovir, text styles valacyclovir, & famicyclovir It Third doesn't level affect the virus in the latent stage. Acyclovir

24 Prevention Avoid contact with herpetic vesicular lesions or ulcers. Acyclovir is given to immunocompromised patients, e.g. transplant recipient.

25 Varicella-Zoster virus (vzv) Diseases Varicella Chicken pox 1ry infection in children A herpes virus Zoster Shingles the reactivated infection in adults

26 Click to edit Master title style Transmission Edit Master text styles Second Inhalation level of droplets from respiratory secretions & saliva Varicella (chicken pox) Direct contact with skin lesions

27 Pathogenesis 1ry viremia Skin 2ry viremia Latent

28 Varicella Chicken pox Clinical picture IP days Fever followed by rash Rash starts in the trunk face & limbs (centrifugal)

29 Macule Papule Vesicle Crust Stages of varicella rash

30 Stages of varicella skin rash Cropping Macule Papule Vesicle Crusts heal without scarring Crust

31 Chicken pox rash

32 Complications: Click to edit Master title style Pneumonia, esp. in adult patients, that may be fatal. Edit Master text styles Fulminant Third level encephalitis Reye s syndrome

33 Complications: Congenital varicella syndrome. The risk is highest if infection was between weeks 13 & 20. Birth defects: - skin scarring, malformed limbs - abnormally small head - neurologic & vision problems

34 Zoster Shingles A Reactivation of latent VZV as varicella but???

35 Zoster Shingles as varicella but??? UNILATERAL & LIMITED SEVERE PAIN

36 Shingle affecting left side of trunk Recurrent varicella zoster on right side of face

37 Complications of Zoster Click to edit Master title style Edit Master Post herpetic text styles neuralgia: Severe pain in the areas affected Second with level shingles rash, even after the rash clears up. Reactivation eye keratitis, conjunctivitis & iritis (herpes zoster opthalmicus) Rarely, shingles can also lead to pneumonia, hearing problems, blindness, encephalitis or death.

38 Laboratory diagnosis of zoster Click to edit Master title style Edit Direct Master text demonstration styles of virus in vesicles Serology Clinically

39 Direct demonstration in vesicular lesions LM: Tzanck smear multinucleated giant cells PCR EM DIF

40 Click to edit Master title style Edit Master text styles Serology Specific VZV abs IIF, Nt or ELISA

41 Treatment Click to edit Master title style Drug of choice Edit Master text styles Acyclovir

42 Prevention Click to edit Master title style Varicella Vaccine Edit Master text styles live attenuated Betw 1-12 yrs.. 2 doses Zoster Vaccine live attenuated For older than 60 yrs 1 dose

43 Prevention Click to edit Master title style Varicella-Zoster IG: Edit Master text styles to exposed immuno-compromised children to mother infected near to term (before delivery) & their infants (immediately after delivery)

44 Group A coxsackieviruses Click to edit Master title style Edit Master text styles

45 Coxsackieviruses A ves. lesions Click to edit Master title style Edit Master text styles Herpangina

46 Coxsackieviruses A ves. lesions Click to edit Master title style Edit Master text styles coxsackievirus A16 Hand, foot & mouth disease

47 Coxsackieviruses A ves. lesions Click to edit Master title style Lab. diagnosis Edit Master text styles Second level Viral culture: throat swabs or involved tissues Serology: 4-fold increase in ab titer. Treatment Symptomatic

48 Click to edit Master title style Smallpox is notable in the history of medicine for two very Edit Master text styles important reasons; Small pox 1-1st human disease for which there was a vaccine 2-1st human disease that has been totally eradicated

49 Factors aided in complete eradication of small pox: Click to edit Master title style The virus has only one stable serotype. Edit Master text styles Diseased individuals are the only source of infection The Third disease level is easily recognized. Infected individuals develop long-lasting immunity. The vaccine used provides high-level immunity.

50 Mode of Transmission & Pathogenesis Click to edit Master title style Similar to???? Edit Master text styles Respiratory droplet Direct contact with skin lesion

51 Clinical manifestations Click to edit Master title style Infection is acute & generalized. Edit Master text styles Skin & many other organs are always involved. The Third 1st levelsymptoms include fever, malaise, head & body aches. A Rash then emerges The lesions may be hemorrhagic & fatal. Two basic forms of this disease: Variola major: mortality rate 20% or higher Variola minor: mortality rate < 1%.

52 Macule Papule Vesicle Pustule

53 Click to edit Master title style Edit Master text styles Crust Scarring Fall off

54 No crops Crops Centripetal Centrifugal

55 Small pox rash

56 Lab. diagnosis of Smallpox Click to edit Master title style Direct demonstration of virus in Vesicular fluid & Edit Master text styles materials from skin lesions Virus Fifth isolation level Serology

57 Direct Virus Demonstration Click to edit Master title style Specimen: Vesicular fluid & materials from Edit Master skin text lesions. styles LM EM

58 Click to edit Master title style Direct Virus Demonstration Edit Master text styles DIF PCR

59 Viral isolation Click to edit Master title style The most reliable lab. test Edit Master text styles Cell culture: Intracytoplasmic IB Chorioallantoic membrane of chick embryo: Pocks formation.

60 Serology Click to edit Master title style Edit Master text ELISA, stylesnt, HI, RIA, & IIF tests

61 Click to edit Master title style Edit Master text styles Vesicular Tumors Maculopapular

62 Measles German measles V. infect. causing MACULOPAPULAR RASH Erythema infectiosum Roseola infantum

63 Click to edit Master title style Measles virus measles (rubeola) Edit Master text styles Second Mode level of Transmission Measles Respiratory droplets & also airborne The disease is most infectious before the rash appears.

64 Pathogenesis Click to edit Master title style Replicates in U & LRT Edit Master text styles Replicates in lymphoid tissue Viremia Epithelial sites

65 Cl.P. of Measles Click to edit Master title style Edit Master text styles IP 1-2 wks Fever Running nose, cough Conjunctivitis (photophobia) Koplik s spot

66 Click to edit Master title style Koplik s spots: Edit Master text styles slightly raised white dots, 2-3 mm in diameter on the inside of the cheeks shortly before rash onset

67 Measles Rash Maculopapular rash extending from face to extremities involving palms & soles, & lasts 3-7 days.

68 Click to edit Master title style Edit Master Long text lasting stylesimmunity Infants are protected from measles for 6-8 months after birth

69 Complications Click to edit Master title style Respiratory : Edit Master text styles Otitis media & bacterial pneumonia are quite common Giant Third level cell pneumonia in patients with impaired CMI (rare but fatal)

70 Complications Click to edit Master title style Neurological: Edit Master text styles Post infectious encephalitis. develops Third levelfew days after the rash disappears (1:1000). Subacute sclerosing panencephalitis (SSPE). develops 1 to 10 years after initial infection (1:1000, 000).

71 Lab. Diagnosis to confirm atypical cases Click to edit Master title style Edit Master Specimen: text styles throat or Second nasopharyngeal level swabs or nasal aspirates. Direct Virus Demonstration: DIF viral ag RT-PCR viral RNA in blood or saliva. Clinically

72 Viral Isolation: Click to edit Master title style Edit Master text styles Multinucleated giant cells with IN & IC IB. Serology: IgM or 4-fold rise in IgG titer.

73 Click to edit Master title style Edit Master text styles Passive Immunization Active Immunization Measles Prophylaxis

74 Passive Immunization Click to edit Master title style Edit Master For text immunocompromised styles patients or people who may have adverse reaction to the vaccine IM within 6 days of exposure.

75 Active Immunization Click to edit Master title style Edit Master A live text attenuated styles vaccine SC Long-term immunity Monovalent or in the MMR vaccine.

76 Click to edit Master title style An acute febrile illness caused by rubella virus. Edit Master text styles The disease affects children & young adults Characterized Third level by rash & lymphadenopathy. German measles (Rubella)

77 Pathogenesis Click to edit Master title style Edit Master It is transmitted text styles by droplet infection. Initial Third level viral replication occurs in the respiratory mucosa multiplication in cervical LNs viremia develops with spread to other tissues.

78 Clinical Picture Click to edit Master title style Edit Master Symptoms text develop styles in 50% of cases IP about 2 wks 1-2 days prodrome of Fever, malaise maculo-papular Rash on face trunk extremities disappears within 3 days. There may be suboccipital & post- auricular Lymphadenopathy.

79

80 Complications Click to edit Master title style Edit Master Rubella text encephalopathy: styles may occur about 6 days after rash usu. lasts only a few days most patients recover with no sequelae

81 Complications Click to edit Master title style Edit Master Maternal text viremia styles during pregnancy in 1st 18 wks infection Second of placenta level & fetus. Growth rate of infected fetal cells is reduced hypoplastic organ development & teratogenic effects.

82 Click to edit Master title style Lab. diagnosis rubella specific IgM antibodies Edit Master text styles Prevention Live attenuated vaccine SC monovalent or combined MMR Single dose immunity for 10 years Vaccinated women should avoid pregnancy for one month after vaccination.

83 Rashes caused by human herpesvirus 6,7 (HHV-6 &7) HHV-6 replicates in T & B cells & also in oropharynx from where it is shed in saliva HHV-6 is the major cause of Roseola infantum (sixth disease), a febrile syndrome, that occurs very common in infants & children. The related HHV-7 is detected in saliva & causes a minority of roseola infantum cases.

84 Clinical manifestations IP 2 weeks Fever that lasts for 3-5 days & when the fever subsides a maculopapular rash is seen on the trunk & neck.

85

86 Erythema infectiosum (5 th disease) Click to edit Master title style It is caused by parvovirus B 19. Edit Master text styles

87 Pathogenesis & clinical manifestations The virus is transmitted by respiratory secretions CCC by mild fever & rash slapped cheek appearance

88 Pathogenesis & clinical manifestations Click to edit Master title style The virus can also cause arthralgia when it infects adults. Edit Master text styles

89 Click to edit Master title style Diagnosis Edit Master parvo text virus styles B19 specific IgM. Treatment Symptomatic treatment. Erythema infectiosum

90 Viruses causing Tumor

91 Human papilloma viruses (HPV) Papillomaviruses cause a variety of skin & mucous membrane lesions that range in severity from benign growths to malignancies. Over 120 types of papilloma virus can infect humans.

92 Click to edit Master title style Mode of Transmission Direct & indirect contact Edit Master text styles Second Genital levelwarts transmission is through sexual contact Pathogenesis HPVs induce epithelial cell proliferation. The majority of infections are self-limited except certain genital HPV types have oncogenic potentials.

93 Clinical manifestations Click to edit Master title style Warts: Edit Master text styles on knees & fingers (HPV 2, 3, 10) Planter warts (HPV 1, 4) Anogenital warts (HPV 6,11,16,18). HPV 16,18 may lead to cervical cancer

94 Click to edit Master title style HPV cl. manifest. Edit Master Juvenile text laryngeal styles papillomas acquired during passage Second through level the birth canal of a mother with genital wart

95 Lab. diagnosis Click to edit Master title style Edit Master text styles PCR DNA hybridization In tissue for detection of DNA

96 Prevention & Control Click to edit Master title style Edit Master Recombinant text styles quadrivalent Vaccine: 4 types of HPV (6,11,16,18) responsible for: 70% of cervical cancers (16, 18) 90% of genital warts (6, 11) For girls & women; age IM doses (0,2 & 6 months)

97 Molluscum contagiosum Click to edit Master title style Edit Master caused text by styles MCV; a poxvirus Mode Third level of transmission Direct or indirect contact Sexual contact.

98 Clinical manifestation Click to edit Master title style Edit Master Small firm, text styles waxy papules, often with umbilicated centers Most often on genitalia, face, or perirectal area. May heal spontaneously within 2-6 weeks. Tends to be self-limited & benign.

99 Diagnosis Click to edit Master title style Edit Mainly Master clinically, text styles however Lab. diagnosis Second can be level made by: EM for demonstration of the virus in exudates from lesions. PCR for detection of viral DNA. Serology NOT used

100 Treatment Click to edit Master title style Edit Master No specific text styles antiviral treatment No available vaccine Generally removed with electrocautery, curettage, or cryotherapy

101 Kaposi sarcoma skin lesions Click to edit Master title style Edit Master HHV 8 text is styles associated with Kaposi sarcoma, a skin Second malignancy level common in HIV patients. Transmitted mostly via saliva. The virus is also involved in the pathogenesis of body cavity-based lymphomas occurring in AIDS patients. Gancyclovir & foscarnet treatment resulted in reduction of Kaposi sarcoma lesion

102 Kaposi s sarcoma

103 Viruses causing Hemorrhagic manifestations in skin Click to edit Master title style Edit Master Bleeding text into styles the skin results in petechiae, purpura, & ecchymoses. e.g. Dengue fever, Ebola & Marburg viruses (will be discussed in blood)

104 Click to edit Master title style Edit Master text styles