Viral Skin Infections

Question 1

pathogenesis of hpv

Answer 1

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

Question 2

characteristic lesions of hpv

Answer 2

• 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

Question 3

types of hpv

Answer 3

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

Question 4

characteristic lesions of anogenital warts

Answer 4

• 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

Question 5

characteristic lesions of flat warts

Answer 5

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

Question 6

characteristic lesions of palmar and plantar warts

Answer 6

• thick endophytic and hyperkeratotic papules

- can be painful with pressure

Question 7

diagnosis of hpv

Answer 7

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

Question 8

benign vs cancerous hpv

Answer 8

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

Question 9

treatment for hpv

Answer 9

• 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

Question 10

t/f children always need to be treated for hpv

Answer 10

false, it can regress spontaneously

Question 11

prevention of hpv

Answer 11

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

Question 12

etiology of molluscum contagiosum

Answer 12

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

Question 13

characteristic lesions of molluscum contagiosum

Answer 13

• 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

Question 14

transmission of molluscum contagiosum

Answer 14

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

Question 15

prognosis and clinical course of molluscum contagiosum

Answer 15

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

Question 16

treatment of molluscum contagiosum

Answer 16

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

Question 17

prevention of molluscum contagiosum

Answer 17

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

Question 18

t/f pox virus is the same as chickenpox

Answer 18

false!!!

Question 19

clinical course of varicella

Answer 19

• 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

Question 20

characteristic lesions of varicella

Answer 20

• 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

Question 21

transmission of varicella

Answer 21

respiratory tract or direct contact (wear gloves!!)

Question 22

complications of varicella

Answer 22

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

Question 23

treatment for varicella

Answer 23

• antivrials beneficial within 24 hours of rash onset

- valacyclovir, famciclovir, acyclovir

Question 24

characteristic lesions of herpes zoster

Answer 24

• 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

Question 25

risk factors for herpes zoster

Answer 25

- older age - cellular immune dysfunction (immunosuppresed) - hiv infection, bone marrow transplant, leukemia, lymphoma, cancer chemo, corticosteroids

Question 26

transmission of herpes zoster

Answer 26

- direct contact and airborne | - less contagious than varicella

Question 27

course and prognosis of herpes zoster

Answer 27

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

Question 28

hutchinson's sign and ramsay hunt syndrome

Answer 28

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

Question 29

diagnosis of varicella and zoster

Answer 29

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

Question 30

treatment for varicella and zoster

Answer 30

- antiviral therapy: famciclovir, valacyclovir, acyclovir - analgesics: lidocaine patch, capsaicin patch, opioids, tcas - phn: gabapentin, pregabalin

Question 31

prevention of varicella and zoster

Answer 31

- vaccine, varizig, pep acyclovir - isolation - airborne and contact precautions

Question 32

hsv1 vs hsv2

Answer 32

hsv1: orofacial hsv2: genital

Question 33

clinical course of hsv

Answer 33

- primary infection: asymptomatic, can transmit | - recurrence: not asymptomatic

Question 34

pathogenesis of hsv

Answer 34

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

Question 35

course of hsv1

Answer 35

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

Question 36

stages of hsv1 infection

Answer 36

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

Question 37

trigger factors for hsv1

Answer 37

anything that causes stress

Question 38

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

Answer 38

hsv2 (genital herpes) also important in acquisition and transmission of hiv

Question 39

course of hsv2

Answer 39

- 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

Question 40

characteristic lesions of hsv2

Answer 40

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

Question 41

diagnosis of hsv

Answer 41

- viral culture (not that accurate) - tzanck smear - pcr!!! - direct fluorescent antibody staining - skin biopsy

Question 42

complications of hsv

Answer 42

- ocular: recurrent keratoconjunctivitis, corneal opacification, visual loss - neurologic: hsv meningitis, hsv encephalitis

Question 43

treatment of hsv

Answer 43

acyclovir or valacyclovir

Question 44

prevention of hsv

Answer 44

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