viral infections of the skin soft tissue, bone, muscle and joints I Flashcards
papilloma
- benign growth of the skin or mucous membranes
macule
- small DISCOLORED patch of skin that forms an area distinct from the normal surrounding surface
papule
- CIRCUMSCRIBED RAISED PORTION OF THE SKIN
vesicle
-small pouch of CLEAR fluid
pustule
full of pus
warts
- hyperkearatotic
- cutaneous are often painless if cutaneous
- CAUSED BY HPV
- LOOK CAULIFLOWER LIKE
Name for common wart
plantar wart
flat warts
verruca vulgaris
verruca plantaris
verruca plana
HPV
- nonenvveloped
dsDNA
replication depends on differentiation status of the tissue
what layer of the skin would you expect to find a new HPV infection
suprabasal
-infected at basal layer, virion matures as moves up
where does the bump come from in warts?
- expanding of all layers due to proliferation
- proliferation initiated so that the virus can use the cell’s machinery to replicate itself
- specifically- HPV-7 and HPV-6 are used to inactivate tumor suppressor cells Rb and P53 respectively causing the cells to go into S phase more and reprematurely
what are the main cutaneous HPV viruses divided into common and plantar warts
- common- 2,3,10
- plantar- 1.4
transmission of HPV? incubation of HPV? diagnosis?
- HPV- direct contact or with contact with surfaces
- 3-4 months
- diagnosis- appearance-koilodal cells (large nuclei with halo/nonstained around them) and hyperkeratosis
Treatment/prevention for HPV
- common and plantar warts usually spontaneous regress after a few months- 2 yrs
- wart removal- cryotherapy, cytotoxic, chemicals, surgical removal
- > NOTE HPV 16, 18, 6, 11: do not protect against cutaneous warts
Molluscum Contagiosum
- painless, pearly, umbilicated, nodules
- seen in genitals (sexual-for adults), hands on kids via contact
- has concavity
- in microscope, it has LARGE AMOUNT IN CELL
- large eosiophilic cytoplasmic inclusions (molluscum bodies)
- poxviridae
- large dsDNA genome
- replicates within cytoplasm - UNIQUE
incubation and transmission of molluscum contagiosum
- 14-50 days
- transmission via direct contact with lesions or fomaite transmission thru a towel or something
treatment of molluscum contagiosum
- often resolution with in 2-12 months without treatment
- removal thru surgery or cryotherapy
Herpes labialis
- cold sores
- painful/[painless and found in vermillion boarder of lip
- a reactivation of the herpes simplex virus
- HOWEVER, AT PRIMARY INFECTION YOU CAN GET A WIDE RAGE OF INFECTIONS LIKE WIDESPREAD INFECTION OF THE MOUTH INCLUDING gingicomastitis (in gums)
- herpes simplex virus
Herpes Simplex keratitis
- leading cause of infectious blindness in US
- initial infection causes conjunctivitis that takes weeks to heal
- recurrent disease lead to corneal opacity
- caused by leading simplex
herpes simplex encephalitis
- rare
- mortality rate over 30% even with antivirals
- commonly leads to neuro probs
- caused by herpes simplex virus
herpetic whitlow
- lesions in the digits
- from herpes simplex
what is the herpes simplex virus
- dsDNA
- latent and lytic phases of the life cycle exist
during a herpes outbreak, what is the productive phase of the life cycle?
-lytic
cold sore pathology
- HSV virus comes and infects the epithelium of the mouth, and replication occurs
- some of the virus gets into the sensory neuron and stays latent there
- when cold sore goes away and there is stress via emotional or traumatic, we get the virus coming out of neuron for outbreak
what is HSV-1 and HSV2 known to cause?
1 = mouth lesions
2= genital lesions
90% of the population has them just not everyone shows it
what is prescribed for herpes? how does it work?
FOSCARNET AND ACYCLOVIR
- acyclovir works like this:
- > relies on the viruse’s thymidine kinase to phosphorylate it converting it to acyclovir monophosphate
- > use cellular kinases to make acyclovir triphosphate which is a nucleotide mimic that allows it to inhibit the viral DNA polymerase incorporation into viral DNA to get CHAIN TERMINATION
Varicella
- chicken pox
- lesions on trunk, scalp and face most
- fever and lesions last approx. 5 days
what is important to note about the lifecycle of varicella?
- it is an evolutionized process
- starts as vesicles -> pustules -> scabs (healing)
- GET “CROPS OF LESIONS”- there are multiple evolutionary stages in a single area of the body
though varicella is seen all over, where is it NOT?
- soles of feet or palms
what are some complications of varicella
- from itching, can inoculate self with bacteria as a secondary infection
- pneumonia - can be due to the viral infection of the lungs or a secondary bacterial infection -> viral has worse outcome and is attributed to MOST OF THE DEATHS FROM CHICKEN POX
chicken pox and pregnancy
first 20 weeks of gestation
vs
infection late gestation
- infection during the first 20 weeks- low birth weight, skin, scarring, encephalitis, chorioretinitis and microcephaly
- infection late in gestation or right after birth- gives lesions on viscera and disseminated infection =worse!!
herpes zoster
- causes shingles- reactivation of VSV
- epidemiology- elderly and immunosuppressed
- get paresthesia (pins and needles) before break out
- GET VESICULAR LESIONS ON FACE AND TRUNK UNILATERALLY
- FLOWS DERMATOMES
- get fever and malaise
postherpetic neuralia
- herpes zoster
- Shingles outbreak that causes pain long after lesions have resolved
what is varicella-zoster virus?
- dsDNA enveloped - herpesviradae fam - LATENT INFECTION- USUALLY IN THE DORSAL ROUTE OR TRIGEMINAL -one serotype
how is varicella-zoster transmitted? incubation time? diagnosis?
- tx- via lesions or respiratory secretions
- incubation time- 2 wks
- diagnosed via TZANCK SMEAR, antibodies, clinical analyses
varicella vaccine
- PREVENTS PRIMARY INFECTIONS
- LIVE ATTENUATED
- grown in tissue culture
- combined with measles, mumps, rubella
- first dose - 12-15 months old
- second dose- 4-6 years old
zoster vaccine
- to protect against from VZV REACTIVATIONS
- SAME LIVE ATTENUATED VACCINE WITH HIGHER TITER
-recommended for all adults over 60regardless
-
when are anti-herpetic drugs used on patients to treat varicella zoster? what drugs are used?
- when patient obtains a primary infection late in the their life
- acyclovir
- varicella is not as susceptible to acyclovir as HSV