Exam 4 skin viral infections Flashcards
Major viral causes of infections with skin presentation (vesicle or pestule)
HHV-1 (neuro, HRM), HHV-2, HHV-3, coxsackievirses A and B, Smallpox, Orf Virus
Major viral causes of infections with skin presentation (maculopapular rashes)
Measles, Rubella, Parvovirus B19, Roseolovirus (HHV-6 HHV-7), HHV-4, ECHO virus, West Nile virus
Major viral causes of infections with skin presentation (wart-like eruptions)
HPV, Molluscum contagiosum
What class is Herpes virus?
Baltimore class I
Does herpesvirus typically integrate into host genome?
no
How do herpesvirus stay in cells?
They make proteins that mediate genome persistence in host cells
What are conditions that can lead to reactivation of herpesvirus
Immune suppression, sexual contact, physical and emotional stress, severe temp changes, sunburns, hormonal changes, malnutrition, excessive fatigue
What are the alphaherpesviruses
HSV-1, HSV-2, varicella zoster virus
What are the betaherpesviruses?
Human cytomegalovirus (HCMV, HHV-6, HHV-7)
What are the gammaherpesviruses?
Epstein Barr virus, Kaposi sarcoma-associated herpesvirus
What are the 6 common childhood diseases?
1st: Measles, 2nd: strep pyogenes (scarlet fever), 3rd: rubella, 4th: SSSS (S. aureus), 5th: Parvovirus B19 (slapped cheeks), 6th: HHV6/7
What are the steps of a viral infection?
Attachment > penetration/adsoprtion > synthesis > assembly > release
How are HSV-1 and 2 transmitted?
Saliva, vaginal secretions, lesion fluid into eyes or breaks on the skin or mucose membranes
Who is at risk of HSV-1 and 2?
children (type 1), sexually active people (type 2). People in healthcare who come into contact with oral or genital secretions
What is the treatment for all herpesviruses?
Acyclovir
How is varicella zoster spread?
virus is transmitted by respiratory droplets or contact
Who is at risk of varicella zoster
Nearly everyone, immunocompromised people
Is there a vaccine for chickenpox?
Yes, live vaccine (Oka strain)
Where do herpesviruses usually stay latent?
Within neurons
What are the disease mechanisms for poxviruses (orthpoxvirus/smallpox)
Infection of respiratory tract, spreads through lymphatics and blood
What is the difference between smallpox and chickenpox in children?
Smallpox lesions all progress and mature at the same time, where chickenpox
How do you stop the spread of picornavirus?
Can use IgA
What causes hand, foot and mouth disease?
Coxsackie A virus (picornaviruses)
What is the useful way for remembering the maculopapular rashes?
“The odds plus 6”- Measles, Rubella, 5th disease (Parvovirus B19), Roseola (HHV6 and 7)
What are complications of measles?
otitis media, croup, bronchopneumonia, encephalitis, subacute sclerosing panencephalitis (SSPE)
What classification are Poxviruses (smallpox)?
Group 1, dsDNA
What classification are picornaviruses (coxsackie A)?
Group IV, ssRNA (+)
What group is measles virus?
Group V, ssRNA (-)
What group is rubella virus?
Group IV, ssRNA (+)
What are complications of a rubella virus?
Can infect fetus of a pregnant woman causing congenital defects
What is fifth disease also known as?
Erythema infectiosum, caused by parvovirus B19
What causes fifth disease?
parvovirus B19
What is the hallmark of fifth disease?
Slapped cheek appearance
What group is parvovirus B19 in?
ssDNA, group 2
What are complications of fifth disease?
aplastic crisis, acute polyarthritis, abortion
How can fifth disease cause an aplastic crisis?
infection of bone marrow erythroid precursor cells
What is sixth disease?
Roseola
What causes sixth disease (Roseola)?
HHV-6 and HHV-7
What are the hallmarks of sixth disease (Roseola)?
High fever (105F), that lasts for 3 days, on fourth day it disappears and maculopapular rash appears
What are the treatments for roseola?
No vaccine or treatments
What causes wart-like rashes?
Human papillomavirus, Molluscum contagiosum virus
How do you diagnose a either HPV or MCV?
clinical diagnosis, histology, microscopy, PCR
What group is HPV?
Group 1, dsDNA
What is a complication of HPV?
tumorigenic
What is the best screening procedure for cervical cancer?
Pap smear: will see huge infected cells
Can molluscum contagious cause cancer?
no
how do you prevent HPV spreading?
vaccine available, avoid direct contact, prevent cancer by screening cervix
