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Viral DiseasesPart 1

• Michael Hohnadel
• KCOM
• 11/25/03

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Herpesvirus Group

• Double stranded DNA virus which replicates in the
  nucleus.
• Produces latent, lifelong infection.
• IncludesVZV, HSV, CMV, EBV, Human Herpes virus
  6, -7, -8. Animal Virus.

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Herpes Simplex

• One of most prevalent infections worldwide.
• 85 of adults are seropositive for HSV-1.
• 20 adults seropositive for HSV-2.
• More are infected than symptomatic disease would
  indicate.
• 50 HSV-1 infected individuals asymptomatic.
• 20 HSV-2 individuals asymptomatic.
• 60 of others do not recognize symptoms as those
  of HSV-2.

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Herpes Simplex

• Diagnosis
• Tzanck Smear
• 60-90 accurate, 3-13 false
• Nonspecific (HSV and VZV)
• Used on acute vesicular lesions
• Multinucleated giant cells jig saw nucleus.
• D. I. F.
• More accurate
• Identifies virus type.
• Viral culture
• PCR
• Biopsy with immunoperoxidase

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Tzanck Smear
Multinucleated giant cell
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Herpes Simplex

• Serologic testing
• Not used to determine if skin lesion is HSV.
• Only indicates infection, not cause of lesion.
• High background positive.
• Used if need to know if previously infected
• Treatment
• Acyclovir, Valacyclovir.
• Action Acyclic nucleoside analog of guanosine
  which inhibits HSV DNA polymerase.

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Orolabial Herpes

• 95 HSV 1
• Presentation Grouped vesicles on an erythematous
  base.
• May occur anywhere inoculated.
• Often prodrome of tingling or itching.
• Variable severity of recurrent lesions.
• Mild flu like symptoms may be present.
• UVB exposure frequent trigger.
• Herpetic Gingivostomatitis
• 1 of infections
• Erosions , ulcers in mouth with white base
  associated with fever, lymphadenopathy and
  malaise.

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Orolabial Herpes
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Orolabial Herpes

• Treatment
• Prevention with sun block and UVB avoidance.
• Acyclovir 200mg bid.
• Acyclovir 200mg 5x / day
• Prophylaxis for dermabrasion, chemical peels,
  laser resurfacing.

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Herpetic Infections

• Herpetic Sycosis
• blade shaving after facial herpes induces a
  slowly spreading folliculitis of the beard with
  few isolated vesicles.
• Herpes Gladiatorum
• Herpetic whitlow
• Herpetic infection of the fingers.
• Healthcare workers, children (thumb sucking)
• Adults 2/3 cases HSV-2, Children nearly 100
  HSV-1

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Herpetic Infections
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Herpetic Whitlow
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Herpetic Infections

• Herpetic Keratoconjunctivitis
• Punctate keratitis or as dendritic ulcers.
• Common cause of vision impairment in the U.S.
• Topical Corticosteroids may cause corneal
  ulceration.
• Recurrences are common.

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Herpetic Keratoconjunctivitis
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Herpetic Infections

• Recurrent Erythema Multiforme Minor
• H.A.E.M. caused by HSV-1 in most cases.
• Presentation Papules some of which become
  classic E.M. target lesions of palms, elbows,
  knees and oral mucosa.
• Atypical lesions 3 multiple or solitary large
  red painful plaques, subcutaneous nodules or
  asymmetric targets.
• Chronic Acyclovir to prevent.

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Erythema Multiforme Minor
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Genital Herpes

• Infection of HSV-2 in 85 of cases.
• Spread by Skin to Skin contact
• Active lesions are infective
• Asymptomatic shedding accounts for the majority
  of transmission.
• Prior HSV-1 infection does not protect from
  HSV-2 infection but may lessen severity of first
  outbreak.
• Primary infection
• Grouped vesicles which appear for 7-14 days.
• Fever, Flu like symptoms, inguinal
  lymphadenopathy, proctitis if rectal involvement.

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Genital Herpes
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Genital Herpes

• Recurrent lesions with typical prodrome of
  burning/itching followed by the formation of
  grouped vesicles which form erosions and heal
  without scarring over 7 days.
• HSV-2 facts
• 20 truly asymptomatic, 20 recognize their
  lesions, 60 have lesion but dont recognize them
  as HSV or dont notice them at all.
• Recurrences are common (6 / year).

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Genital Herpes - Treatment

• Primary Lesions
• Acyclovir 200-400 mg five times/ day. Also,
  Valacyclovir 1000 mg bid.
• Recurrent lesions ( 6 lesions/ year)
• Acute lesions
• Acyclovir 200mg 5 times daily. Also,
  Valacyclovir 500 mg bid.
• Suppressive therapy
• Acyclovir 400 mg bid or tid suppresses 85 of
  recurrences. 20 recurrence free during TX.
• Also Valacyclovir 500 mg QD (1000 mg QD if 10
  recurrences / year.)
• After 10 years of suppressive TX, many pts can
  stop medication and retain a reduction in number
  of lesions.

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Intrauterine and Neonatal Herpes

• Prevalence 1500 2000 cases / year.
• 70 HSV-2 acquired at time of delivery.
• Intrauterine infection (rare)
• Primary lesions of mother
• May cause fetal anomalies skin lesions, scars,
  microcephally, microphthalamos, encephalitis,
  calcifications.
• Almost always permanent sequelae.
• HSV-1 acquired through postnatally by contact
  with orolabial disease.

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Intrauterine and Neonatal Herpes

• Extent of initial involvement predicts outcome
• Localized rarely fatal. 10 with long term
  sequelae
• Disseminated disease fatal 15-20. If brain
  dissemination, 50 with long term sequelae.
• Presentations in newborns
• 70 present with skin vesicles. Incubation of 3
  wks, vesicles may appear after discharge.
• Disseminated herpes with CNS involvement may
  occur without skin involvement.
• 20 of cases never have vesicles.
• TX Acyclovir 250 mg/(m)2 q8 hours x7 days

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Neonatal Herpes

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Neonatal Herpes
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Intrauterine and Neonatal Herpes

• Prevention and management
• 70 of mothers of HSV infected infants are
  asymptomatic at delivery and have no HX of
  infection.
• Primary vs secondary infection at time of
  delivery as well as active lesions important.
• Active recurrent lesion 2-5 risk of HSV
  infection.
• Active primary lesion 33-50 risk of HSV
  infection.
• If active lesions at time of delivery then
  C-section.
• Pregnancy with HSV infection controversial
• Routine cultures not recommended.
• Avoid scalp electrodes.
• HSV-1 more frequently transmitted.
• If primary lesion during pregnancy Acyclovir
  during 3rd trimester.

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Disseminated HS infection

• Newborns, premature, malnourished, Immnosup. and
  children to age 3 years are at risk.
• Presentation Severe herpetic gingivostomatitis
  followed by dissemination to viscera esp. the
  liver, lungs and GI and brain.
• Death possible
• TX Acyclovir

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Eczema Herpeticum

• Also called Kaposis Varicelliform eruption.
• Herpes infection in pt with atopic dermatitis
  results in infection throughout the eczematous
  areas with hundreds of vesicles.
• Also occurs in Dariers, pemphigus, pemphigoid,
  Wiskott-Aldridge or burns.
• Self limited in healthy individuals.
• TX IV or oral acyclovir in all cases

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Eczema Herpeticum

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Eczema Herpeticum
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Herpes Simplex in theImmunocompromised

• Any erosive mucocutaneous lesion should raise
  suspicion of herpes simples.
• Often less vesicular and more erosive with
  crusting
• Hallmarks 1.) Pain 2.) active vesicular border
  3.) scalloped periphery.
• Extensive involvement.
• Tzanck smears less valuable (erosions)
• DIF is specific and rapid if needed.
• TX Acyclovir. Consider suppressive therapy
• Acyclovir resistance cases foscarnet

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Immunocompromised
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Immunocompromised
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Varicella

• Infection with Varicella Zoster
• Transmission by contact or respiratory route.
• Initially virus seeds the internal organs at 4-6
  days. At 11-20 days the skin eruption occurs.
• Individuals are infectious 4 days before and 5
  days after exanthem appears.
• In adults 30.9 / 100,000 death rate.

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Varicella

• Presentation Faint erythematous macules develop
  into teardrop vesicles in 24 hours. Fresh crops
  of vesicles appear for several days on trunk,
  face or oral mucosa. Vesicles become pustular,
  umbilicated and crusted. Number of lesions
  averages about 300.
• Secondary bacterial infection may result in
  scarring.
• Other complications
• Pneumonia neonates and adults (1/400)
• Reyes syndrome encephalitis, hepatitis with
  aspirin use.
• Thrombocytopenia
• Purpura Fulminans DIC with low proteins C and S

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Varicella
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Varicella
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Varicella
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Varicella

• Treatment
• Acyclovir for severe cases, high risk individuals
  and adults (13 years).
• No Aspirin!!!
• Topical Antipruritics
• Isolate from immunocompromised.

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Varicella

• Prevention
• Varicella Vaccine
• Live attenuated virus
• 95 effective
• Those who do contract varicella have mild case.
• At present immunity appears to be lasting.
• Modified Varicella-like syndrome (MLSV)
• 15 days after exposure to varicella virus.
• 35-50 macules and papules, few vesicles.
• Mild, afebrile course lasting 5 days

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Varicella in Pregnancy

• Increased risk of spontaneous abortion (3 by 20
  wks), congenital varicella syndrome and fetal
  death. Possible increase in pre-term labor.
• Mother at increased risk for varicella pneumonia.
• Congenital Varicella Syndrome
• Hypoplastic limbs, scars, ocular and CNS
  disease.
• F M
• 1-2 risk, highest between weeks 13 and 20.

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Congenital Varicella Syndrome
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Varicella in Pregnancy

• Fetal infection may result in Herpes Zoster early
  in life (
• Occurs in 1 of VZ complicated pregnancies with
  highest risk at wks 25-36 wks gestation.
• Prevention VZIG for non-immune pregnant mothers
  within the first 72-96 hours of exposure.
• Use only with proven seronegativity. Only 20 of
  those who relate neg. HX of VAR infection earlier
  in life are seronegative.

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Varicella in Pregnancy

• Neonatal Risk
• Mother who develops varicella 5 days before to 2
  days after childbirth places newborn at risk for
  severe varicella.
• Virus acquired transplacentally before mother has
  produced antibodies. Newborns immune system is
  very vulnerable.
• Treatment VZIG and Acyclovir
• No treatment mortality 30

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Varicella in the Immunocompromised

• May result severe and protracted infections.
• Consider in cancer, AIDS and for those on
  systemic steroids or other immunosuppressive
  meds.
• More numerous lesions, more necrotic lesions,
  Large lesions.
• Prior infection is not protective
• Non dermatome distribution may indicate
  reactivation.
• Before TX available, 1/3 of children with cancer
  developed complications of varicella and 7 died.

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Varicella in the Immunocompromised

• Treatment and Prevention
• VZIG
• Given within 96 hours after high risk exposure
• Household contact with VZ, face to face/5 min
  contact, Indoors with VZ for 1 hour.
• Reduces severity of infection, not frequency.
• No proven value once clinical disease develops.
• Varicella vaccination before anticipated
  immunosuppression is helpful
• Acyclovir
• IV acyclovir given until two days after new
  vesicles stop appearing. In HIV cases, until
  vesicles have healed.
• Also Valacyclovir, Famciclovir.
• Crucial to give for adequate time in adequate
  dose to prevent resistance.

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Herpes Zoster

• Reactivation of latent herpes zoster infection
  from the dorsal root ganglia
• Over 1-5 days new lesions develop. These become
  pustular and crust.
• Typically along a dermatome with some overflow to
  adjacent dermatomes.
• Preceded by pain, itching several days
• Duration of the lesion is dependent on
• Age. Young 2-3wks, Older 5-6wks
• Severity of lesions
• Immunosuppression
• Incidence of H.Z. increases with age (esp50 yrs)
  and immunosuppression.

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Herpes Zoster
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Herpes Zoster

• Heals without scaring in young. Increased
  incidence of scaring in elderly and severe
  eruptions.
• Subtypes of Herpes Zoster
• Disseminated Zoster
• Defined as 20 vesicles outside dermatome.
• Chiefly elderly or Immunocompromised
• Hemorrhagic/gangrenous lesions with outlying
  vesicles or bullae.
• Systemic symptoms include fever, H.A., meningeal
  irritation. Rarely, encephalitis.

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Disseminated Herpes Zoster
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Herpes Zoster

• Zoster Subtypes (Continued)
• Ophthalmic Zoster
• Involvement of fifth cranial nerve, ophthalmic
  branch
• Lesion location verses eye involvement
• If tip/side of nose Hutchinsons sign, eyeball
  affected 76 vs 34 if not involved.
• If lid margin affected virtually 100
  involvement.
• Ocular complications
• Uveitis 92
• Keratitis 50
• Less common glaucoma, optic neuritis, retinal
  necrosis
• Other encephalitis
• Lesions tend to reoccur (as long as ten years).
• Ophthalmology consult.

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Hutchinsons sign
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Herpes Zoster

• Zoster Subtypes (Continued)
• Ramsay Hunt syndrome
• Facial and auditory nerve involvement with
  inflammation of geniculate ganglion.
• Zoster of external ear or TM, herpes auricularis,
  with ipsilateral facial paralysis
• Herpes auricularis, facial paralysis and auditory
  symptoms.

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Ramsay Hunt syndrome
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Herpes Zoster

• Inflammatory skin lesions following H.Z.
• Occur 1-3 months in previously affected
  dermatome.
• Flat topped or annular papules
• Granulomatous histopathology with no viral
  genome.
• Resolve spontaneously. Topical or intralesional
  steroids may be used
• Diagnosis of Herpes Zoster
• Tzanck, direct fluorescent antibody, culture,
  PCR.

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Herpes Zoster Treatment

• Corticosteriods
• Reduce severity of acute pain, returns pt to full
  activity sooner.
• No evidence that they shorten duration of acute
  pain or prevent post herpetic neuralgia when
  given with an antiviral.
• Acyclovir
• May lessen severity of symptoms in acute
  outbreak. May lessen incidence of PHN.

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Herpes Zoster

• Postherpetic neuralgia
• Persistent pain after cutaneous lesion heal.
• Age dependant Rare under 40yrs. 75 over
  70 will have pain beyond one month.
• Usually gradual improvement
• Pain may worsen or persist for years.

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Herpes Zoster

• Treatment of Post Herpetic Neuralgia (Quick
  intervention)
• Topical Capsaicin, topical lidocaine, aspirin.
• Oral analgesics NSAIDS
• Tricyclic antidepressants /- neurontin
• Injected lidocaine/steriod solutions
• Opiates
• Nerve blocks can provide long lasting relief.

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Epstein Barr Virus

• Infectious mononucleosis
• General After 3-7 wk incubation period,
  bilateral enlargement of cervical and other lymph
  glands with high fever, malaise and HA, possible
  enlargement of the spleen. Pharyngitis with
  hyperplasia of lymphoid tissue are the most
  frequent signs. Atypical lymphocytosis.
• Cutaneous presentation edema of eyelids and a
  macular or morbilliform rash. Macular eruption
  is located on trunk. Mucous membranes with 5-20
  pinhead sized petechiae at junction of soft
  palate with hard. (Forsheimer spots)
• Rarely scarlatiniform, herpetiform, E.M.,
  purpura.

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Forsheimer spots
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Morbilliform Reaction after Ampicillin
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Epstein Barr Virus

• Lab findings
• WBC count 10,000 to 40,000.
• Abnormal large lymphocytes (Downey cells) are 10
  of total leukocyte count.
• Heterophile antibodies 1160 of higher
• EBV is associated with lymphoma esp. Hodgkin's
  disease.
• Treatment supportive.

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Infectious mononucleosis
Reactive atypical lymphocytes have pleomorphic
reticular nuclei, peripheral basophilia of
cytoplasm, and scalloped cell borders
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Oral Hairy Leukoplakia

• Associated with chronic shedding of EBV in the
  oral cavity.
• Presentation Poorly demarcated, corrugated,
  white plaques on lateral aspect of tongue.
• Unlike thrush, cannot be removed by scraping.
• Occurs with immunosuppression (esp AIDS) and
  warrants HIV workup.
• Treatment
• No required
• If requested podophyllin and tretinoin are used
  but lesions will reoccur.

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Oral Hairy Leukoplakia
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Cytomegalic Inclusion Disease

• Infects 50-80 of adults, 1 of newborns.
• Newborns
• 90 asymptomatic
• 10 with symptoms. More severe if mother had a
  primary infection.
• Systemic
• Jaundice, hepatosplenomegally, calcifications,
  chorioretinitis, MR, deafness, microcephally.
• Cutaneous
• Petechia, prupura and ecchymosis
• Bluberry muffin baby - generlized macular,
  papular erruption.

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Blueberry Muffin CMV
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TORCH infant with CMV
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Cytomegalic Inclusion Disease

• Symptomatic infection in adults is unusual and is
  like that of EBV.
• May see morbilliform eruption if ampicillin
  given.
• CMV infection of the skin
• Rare, usually immunosuppressed. Identical to HSV
  or VZ
• May cause superficial ulcerations or fissures of
  oral or anal area. Erosive diaper dermatitis
• Pathogenic CMV is present in the dermal vessels,
  not the epithelium.
• Difficult to determine CMV as causative.

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CMV Ulcerations
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Cytomegalic Inclusion Disease

• Treatment of CMV ulcerations
• CMV virus is diagnosis of exclusion.
• Normal skin can shed CMV. Pathogenicity hard to
  prove. Electron microscopy cant distinguish
  among HSV, VZ and CMV.
• Antiherpetic agents acyclovir, foscarnet,
  gancyclovir, cidofovir.
• Lesions that fail to respond treated as aphthous
  equivalents

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Human Herpesvirus 6 and 7

• Roseola Infantum (sixth disease)
• Presentation Onset of high fever which resolves
  in about 4 days followed by a morbilliform
  erythema of rose colored macules on neck, trunk
  and buttocks and sometimes the face and
  extremities.
• Halo may surround lesions.
• Complete resolution in 1-2 days.
• HHV 6 infection is nearly universal.
• HHV 7 similar to 6. May occur later.
• In adults, may resemble mononucleosis.

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Roseola Infantum
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Roseola Infantum
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Human Herpes Virus 8

• HHV-8 is found to be associated with Kaposis
  Sarcoma in virtually all cases.
• Includes AIDs, African and Mediterranean cases.
• Seroprevalence correlates with prevalence of KS
  in a given population.
• Infection predicts and precedes subsequent
  development of KS.
• HHS-8 is found in KS lesions, saliva, blood and
  semen of infected individuals.
• Associated with body cavity based B-cell
  lymphoma.
• Found in all cases of Castlemans disease assoc
  with HIV, and a large portion of non-HIV cases.

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Kaposis Sarcoma
Plump spindled cells outlining vascular spaces
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Kaposis Sarcoma
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B Virus

• Herpesvirus Simiae. Infects monkeys with
  vesicular lesions similar to HSV on oral mucosa,
  lips or skin.
• Humans infected by contact.
• Within a few days of the bite, vesicles and
  intense erythema appear at site of injury with
  rapid progression to fatal encephalitis in many
  cases (15 of 22 studied). All survivors of
  encephalitis had severe neurological sequelae.
• Recurrence is possible in infected individual.
• Treatment Early antiviral HSV.

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B Virus
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B Virus
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Gianotti-Crosti Syndrome

• Presentation Monomorphous eruption of flat
  topped, erythematous papules or papulovesicles,
  1-5 mm in diameter that erupt suddenly and
  symmetrically.
• Favors face, buttocks and extensors and spares
  the trunk.
• Last 2-4 weeks
• Pruritis is variable
• Mucous membranes are spared.
• May have lymph node enlargement, spleenomegally.
• Affects children 6 mo to 14 yrs.
• Association with Hep-B and many other viral
  infections.
• Acute anicteric Hep-B symptoms occur near time of
  onset.

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Gianotti-Crosti Syndrome

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Gianotti-Crosti Syndrome
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Hepatitis B infection

• Presentations
• Urticaria, arthralgias, GN, vasculitis several
  days to weeks before onset of clinically apparent
  liver disease.
• 10-20 of infections.
• Nearly always yields clinical Hep-B.
• Due to Hep-B antigenemia and tracks resolution of
  antigen.
• PAN may be seen during acute infection or up to
  12 years post infection
• Hep-B may be silent.
• 593 dermatologist 15.4 showed evidence of
  previous Hep-B infection !!!!
• Get Vaccinated.

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Hepatitis-C Infection

• 50 infected become chronic, 50 with cirrhosis.
  Increased hepatocellular carcinoma.
• Presentations
• Necrotizing vasculitis assoc with Type II
  cryoglobulin in 84 of cases. Leukocytoclastic
  vasculitis.
• 2-5 of Hep-C infections.
• Palpable purpura of LE most common presentation.
• Also Livedo reticularis and Urticaria.

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Hepatitis-C Infection

• Presentations (cont)
• 12-31 of PAN patients Hep-C positive.
• PCT associated. 10-95 based on population
  studied.
• Interferon helps
• 4-38 of Lichen Planus patients have HCV.
• Interferon may not help.

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Variola MajorSmall Pox

• History
• Last reported cases in U.S. 1949 in Texas.
• Last Case in world Somalia 1977-80s ?
• Last public U.S. vaccination 1972.
• Spread by respiratory droplets, infected skin
  contact, shed skin.
• Presentation
• After an incubation of 12 days, sudden onset of
  fever and malaise which cease abruptly when
  exanthem appears.
• In synchrony, erythematous macules become papular
  then vesicular, pustular and finally crust in two
  weeks.

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Variola Major

• Centrifugal pattern (face arms legs worse).
• Deep seated, large vesicles. Vesicles may occur
  on palms and soles.
• Crust separate to leave fresh scars, permanent in
  half of cases.
• Complications pneumonitits, corneal destruction,
  encephalitis, jt. effusions, osteitis.
• Contagious period.
• Less contagious when fever begins
• Most contagious when lesions develop and remains
  contagious until the last scab is shed.
• Treatment - supportive

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Variola Major
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Variola Major
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Variola Major

• Public Health Bioterrorism Issues
• Pre-1972 vaccinations are not considered
  protective at present but may reduce severity.
• Currently, enough vaccine (diluted) for entire
  U.S. population.
• Time window to receive vaccination should
  outbreaks occur
• If given within 3 days of exposure, vaccination
  is protective/greatly reduces severity of
  infection.
• Within 4-7 days is likely beneficial to outcome.

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Chickenpox vs Smallpox
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Vaccinia

• Not currently available to general public.
• Used for immunization after 1 year of age.
• Hybrid of Cowpox and Variola
• Expected Patterns of Vaccination reactions
• Primary response
• Day 5 papule then vesicle
• Day 9 Maximal reaction with pustule and
  regional lymph node enlargement.
• Accelerated response in partially immune
  Vesicle which involutes by day 10.
• Immediate reaction in immune Papule which
  involutes by 3rd day.
• Typically heals with scarring.

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Vaccinia - Unimmunized
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Specific Contraindications to Routine Vaccination

• See AAD Guidelines.
• Allergy to smallpox vaccine or components
• Heart problems
• Skin conditions
• Weakened immune system
• Pregnancy/breastfeeding
• Infants and children
• Moderate or severe illness

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Vaccinia

• Complications of Vaccination
• Generalized Vaccinia
• 4-10 days after vaccination papules become
  papulovesicles become pustules in crops which
  involutes over 3 wks.
• Ocular paralysis, retinitis.
• Autoinoculation to other body sites from own
  vaccination of someone else.
• Eczema Vaccinatum
• Widespread lesions in chronic dermatitis
• 1 mortality

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Eczema Vaccinatum
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Vaccinia

• Vaccinia Necrosum
• Vesicular involving the skin and mucous membranes
  which persist for months and become gangrenous
  resulting in death in 33.
• TX Vaccinia immune globulin from red cross.
• Roseola Vaccinia
• Extensive, symmetric, morbilliform eruption
  appearing 2 weeks after vaccination. Vaccination
  site with crust and large erythematous halo.
• Do not coalesce
• Involutes in several days.

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Vaccinia Necrosum
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Roseola Vaccinia
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Vaccinia Reactions

• Treatment for Vaccinia Necrosum
• and Vaccinatum reactions.
• Vaccinia Immune Globulin (VIG) reduced previous
  mortality significantly.
• Cidofovir possibly helpful.

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Cowpox

• Presentation Solitary macule/vesicle/pustule
  evolution. Becomes blue-purple and hemorrhagic.
  A 1-3 cm, painful eschar develops after 2-3 wks.
• Always painful
• Lymphadenopathy. Systemically ill pt.
• Heals 6-8 weeks with scarring
• Etiology Orthopoxvirus restricted to Britain,
  Europe and Russia.
• Zoonosis. (Small animals are usual source.)
• Domestic cat usual source of infection. Infects
  cows rarely. (Catpox ??)
• DX viral culture, Serology.
• TX No treatment.

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Cowpox
103
Farmyard Pox

• Milkers nodules and Orf.
• Presentation Similar for both entities.
• Six stages over six weeks.
• Stage 1 / Maculopapular - A red elevated lesion.
• Stage 2 / Target - A bulla with an irislike
  configuration (nodule with a red center, a white
  middle ring, and a red periphery).
• Stage 3 / Acute - A weeping nodule.
• Stage 4 / Regenerative - A firm nodule covered by
  a thin crust through which black dots are seen.
• Stage 5 / Papillomatous - Small papillomas appear
  over the surface.
• Stage 6 / Regressive - A thick crust covers the
  resolving elevation.
• Mild systemic symptoms (compare to cowpox)

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Farmyard Pox

• Milkers nodule
• Occupational disease of vets and milkers
  transmitted by utters of cows.
• Usually solitary lesions with course as described
  prev.
• Orf
• Sheep farmers. Common affliction.
• Transmitted by direct contact or through fomites
  since virus is durable.

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Milkers Nodule
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ORF
Early lesion
Target like lesion.
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Orf
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Orf
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Farmyard Pox

• Histologic features
• Pseudoepitheliomatous hyperplasia. Keratinocytes
  with viral inclusion with pale halo and
  vacuolization. Massive capillary proliferation
  and dilation.
• Treatment
• Supportive. Shave may shorten duration.
• No human to human transmission occurs.

110
Bovine Papular Stomatitis

• Presentation After 5-8 day incubation, a lesion
  similar to milkers nodule forms lasting about 3
  wks.
• Affected cattle may not have evident lesions.
  (Unlike milkers nodule)
• DX virus culture
• TX Self limited.

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Parapoxvirus from Wildlife

• Several cases of infection from cleaning deer or
  camping in area with wild deer.
• Viral particles identified by EM.