Viral Skin Infections Flashcards Preview

15 Derma > Viral Skin Infections > Flashcards

Flashcards in Viral Skin Infections Deck (44)
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1
Q

pathogenesis of hpv

A

spread by direct contact -> virus enters basal cell -> cellular proliferation

2
Q

characteristic lesions of hpv

A
  • verruca vulgaris
  • scaly, rough, spiny papules or nodules
  • can be single or grouped papules on hands and fingers or elsewhere
  • punctate black dots = thrombosed capillaries, evident after shaving off outer keratinous surface
3
Q

types of hpv

A

common warts/ verruca vulgaris = hpv 2 1 27 29
anogenital warts = 6 and 11
flat warts/ verruca plana = 3 10 28 49
palmar/plantar = 1

4
Q

characteristic lesions of anogenital warts

A
  • condyloma acuminata
  • epidermal and dermal nodules/papules on perineum, genitalia, crural folds, anus
  • can form large exophytic cauliflower like masses
  • 1-3 mm sessile warts on penis shaft
5
Q

characteristic lesions of flat warts

A
  • verruca plana
  • 1-4 mm, slightly elevated, flat-topped papules with minimal scale
  • frequent on face, hands, neck, lower legs
  • pinkish or hyperpigmented
6
Q

characteristic lesions of palmar and plantar warts

A
  • thick endophytic and hyperkeratotic papules

- can be painful with pressure

7
Q

diagnosis of hpv

A
  • hx and pe
  • dermoscopy: (+) black dots
  • histopath: koilocytes (viral particles around nucleus
  • 3-5% acetic acid to visualize genital warts
8
Q

benign vs cancerous hpv

A

benign: 1, 2, 6, 11
cancer: 16, 18, 6 (rare)

9
Q

treatment for hpv

A
  • physical destruction: cryotherapy, electrocautery and curettage!!, scissory excision
  • topicals: imiquinod 5% cream (genital!!), salicylic acid, tca 70-90%, 5% potassium hydroxide
  • also examine sexual partner
10
Q

t/f children always need to be treated for hpv

A

false, it can regress spontaneously

11
Q

prevention of hpv

A
  • nongenital: direct exposure to lesions or fomites
  • genital: use condoms, monogamy
  • vaccine (quadrivalent or bivalent)
12
Q

etiology of molluscum contagiosum

A
  • pox virus
  • benign and affects young children
  • sexually transmitted in adults
  • great concern: immunocompromised or atopic dermatitis
13
Q

characteristic lesions of molluscum contagiosum

A
  • smooth dome-shaped, opalescent papules with central core, can get to 3 cm
  • enlarge = central dell or umbilication + white curd like substance
  • surrounding erythema = immune response = GOOD SIGN
  • patients scratch –> bacterial infection = BAD SIGN
14
Q

transmission of molluscum contagiosum

A
  • direct skin or mucous membrane contact
  • fomites (baths, towels, close contact sports)
  • autoinoculation
  • koebnerization
  • vertical transmission
15
Q

prognosis and clinical course of molluscum contagiosum

A
  • spontaneous clearance
  • prolonged course (months to years)
  • indicative of advanced state of hiv if high viral load or low cd4 tcell count
16
Q

treatment of molluscum contagiosum

A
  • watch and wait!!
  • cantharidin*
  • curettage (painful)
  • incision and drainage
  • cryotherapy (painful)
  • other topical modalities*
  • oral cimetidine
17
Q

prevention of molluscum contagiosum

A
  • avoid trauma to sites of involvement and scratching
  • use antipruritics
  • treat all existing lesions to avoid autoincoulation
18
Q

t/f pox virus is the same as chickenpox

A

false!!!

19
Q

clinical course of varicella

A
  • acute highly contagious exanthem during childhood
  • prodrome of mild fever, malaise and myalgia
  • infectious for 1-2 days -> exanthem appears, 4-5 days -> vesicles crust
  • incubation period 14-15 d
  • self-limited and benign in healthy children
20
Q

characteristic lesions of varicella

A
  • begins on the face and scalp -> trunk, sparing extremities
  • rose colored macules -> papules, vesicles, pustules, and crusts (dew drops on a rose petal)
  • can involve oral mucosa
  • crusts fall off spontaneously in 7-10 days

hallmark: lesions in all stages are present on the body at the same time

21
Q

transmission of varicella

A

respiratory tract or direct contact (wear gloves!!)

22
Q

complications of varicella

A
  • 2ndary bacterial infection + scarring
  • cns sequelae uncommon (encephalitis and acute cerebellar ataxia)
  • reye’s syndrome (encephalitis + fatty liver) rare
  • pneumonia
23
Q

treatment for varicella

A
  • antivrials beneficial within 24 hours of rash onset

- valacyclovir, famciclovir, acyclovir

24
Q

characteristic lesions of herpes zoster

A
  • UNILATERAL dermatomal pain and paresthesia + rash
  • from reactivation and multiplication of endogenous latent vzv in sensory ganglia
  • most common debilitating complication: chronic pain / postherpetic neuralgia
  • common locations: trigeminal nerve (ophthalmic division), trunk from t3 to l2
25
Q

risk factors for herpes zoster

A
  • older age
  • cellular immune dysfunction (immunosuppresed)
  • hiv infection, bone marrow transplant, leukemia, lymphoma, cancer chemo, corticosteroids
26
Q

transmission of herpes zoster

A
  • direct contact and airborne

- less contagious than varicella

27
Q

course and prognosis of herpes zoster

A
  • 12-24 hrs: vesicles
  • day 3: pustules
  • day 7-10: dry and crust
  • crusts persist for 2-3 wks
28
Q

hutchinson’s sign and ramsay hunt syndrome

A

hutchinson’s sign: involvement of nasal branch of the nasociliary nerve + ophthalmic complications (uveitis, keratitis, blindness)

ramsay hunt syndrome (facial and auditory nerves): facial palsy + herpes zoster of external ear or tympanic membrane +/- tinnitus

29
Q

diagnosis of varicella and zoster

A
  • clinical
  • tzanck smear: (+) multinucleated giant cell
  • definitive diagnosis: isolation of virus in cell culture
  • pcr and elisa
30
Q

treatment for varicella and zoster

A
  • antiviral therapy: famciclovir, valacyclovir, acyclovir
  • analgesics: lidocaine patch, capsaicin patch, opioids, tcas
  • phn: gabapentin, pregabalin
31
Q

prevention of varicella and zoster

A
  • vaccine, varizig, pep acyclovir
  • isolation
  • airborne and contact precautions
32
Q

hsv1 vs hsv2

A

hsv1: orofacial
hsv2: genital

33
Q

clinical course of hsv

A
  • primary infection: asymptomatic, can transmit

- recurrence: not asymptomatic

34
Q

pathogenesis of hsv

A

virus contacts skin -> replicates in dermis/epidermis -> infects and becomes latent in trigeminal or sacral sensory genitalia -> recurs where nerve innervates (not whole dermatome)

35
Q

course of hsv1

A
  • primary infection: childhood, herpetic gingivostomatitis, pharyngitis
  • reactivation: perioral facial area, outer 1/3 of lip, vermillion border
36
Q

stages of hsv1 infection

A
  • developmental stages: prodrome, erythema, papule
  • disease stage: vesicle, ulcer, hard crust
  • resolution stages: dry flaking and residual swelling
  • resolve in 5-15 days
37
Q

trigger factors for hsv1

A

anything that causes stress

38
Q

most prevalent sexually transmitted disease, most common cause of ulcerative genital disease

A

hsv2 (genital herpes)

also important in acquisition and transmission of hiv

39
Q

course of hsv2

A
  • acute first episode
  • extensive genital lesions in different stages of evolution
  • pain, itching, dysuria, vaginal and urethral discharge, tender inguinal lymphadenopathy
  • recurrence: first months to years
40
Q

characteristic lesions of hsv2

A
  • multiple small grouped vesicular lesions in genital area
  • prodrome: itching, burning, tingling
  • heal in 6-10 d
41
Q

diagnosis of hsv

A
  • viral culture (not that accurate)
  • tzanck smear
  • pcr!!!
  • direct fluorescent antibody staining
  • skin biopsy
42
Q

complications of hsv

A
  • ocular: recurrent keratoconjunctivitis, corneal opacification, visual loss
  • neurologic: hsv meningitis, hsv encephalitis
43
Q

treatment of hsv

A

acyclovir or valacyclovir

44
Q

prevention of hsv

A
  • patient education and safer sex practices
  • outbreak: refrain from sex and 1-2 d after, use condoms
  • vertical transmission low
  • suppressive antiviral therapy