Viral Infections Flashcards
1
Q
What are warts?
A
Benign infections of the skin & mucous membranes caused by HPV
2
Q
Epidemiology of warts?
A
- Cutaneous warts common in children and young adults, incidence reduces with age.
- In children genital lesions may result from autoinnoculation from cutaneous lesions
> should raise suspicion of sexual abuse when extensive.
2
Q
Transmission of infection of warts?
A
- Genital infection
- by intimate contact with affected individuals. - Non-genital (skin) infection
- Directly: person to person contact
- Indirectly: contaminated surfaces/objects; swimming pools, gyms etc.
Note: Individuals with sub-clinical infection can transmit the virus.
3
Q
Clinical features of warts and what they depend on?
A
depend on HPV type and anatomic site of infection.
1. cutaneous lesions: HPV 1,2,3,4 and 10
2. mucosal lesions: HPV 6 and 11
4
Q
Clinical classification of cutaneous warts?
A
- Common warts (veruccae vulgaris)
- Palmar-plantar warts
- Flats warts
- Filiform/digitate warts
5
Q
Describe the appearance of common warts?
A
appear singly or grouped as rounded papules or nodules with rough, grayish scaly surface.
6
Q
Location of common warts?
A
- common on sites prone to trauma but may locate anywhere
- fingers, dorsal surfaces of the hands, knees, elbows - Can also involve the nail
- around nail plate: periungual
- under nail plate: subungual
7
Q
Common causes of common warts?
A
HPV 1,2,4, 27, 57, 53
8
Q
Describe palmar and plantar warts?
A
- Thick, endophytic, hyperkeratotic papules on the palms, soles and lateral surfaces of hands and feet
- have gently sloping sides with central depression (hence myrmecia [antihill] warts)
- Mosaic warts: coalescence into plaque of superficial plantar warts
- May be extensive & painful when walking due to deep ingrowth
9
Q
Common causes of palmar and plantar warts?
A
HPV 1,2,4,27 and 57
10
Q
Describe filiform/figitate warts?
A
- Located on the beard area, periorally, alae nasi and around the eyes.
- Manifest as several skin coloured finger-like projections emanating from a narrow base.
11
Q
Describe flat warts?
A
- 1 to 4 mm slightly elevated, flat topped papules with minimal scale.
- Commonly located on the hands, arms or face often in a linear array – demonstrating Koebner phenomenon.
- Can be quite resistant to treatment, especially in HIV immune suppresion
12
Q
Flat warts causes?
A
HPV 3, 10, 28 and 41
13
Q
What is epidermodysplasia verucciformis?
A
- Autosomal recessive inheritance with unique susceptibility to HPV 5 and 8.
- Starting from childhood, widespread flat or minimally scaly lesions resembling P.versicolor
- Always recur after treatment.
- May transform to SCC in sun-exposed areas
14
Q
Principles of treatment of viral warts?
A
- No single effective treatment
- Some patients may chose to leave their lesions for spontaneous resolution.
- Decision to treat should be based on individual basis
- Where treatment is opted, aim should be to cure, but control of spread and relief of symptoms may be acceptable.
- Paring the wart where possible to enhance effect of drug.
- If drug used for 6 months without change, consider next level
15
Q
First line therapy treatment for warts?
A
- Salicylic acid generally reserve concentration of more than 15 % to plantar and palmar surfaces
- Glutaldehyde 10 % solution or gel 2x daily
- Silver nitrate stick
16
Q
Second line therapy for warts?
A
Cryotherapy (avoid its use in peri and subungual)
17
Q
Third line therapy for warts?
A
- Immiquimoid
- 5 fluoro uracil
- contact sensitisers
- cimetidine
- levimazole
18
Q
Surgical treatment of warts?
A
- currettage
- excision
19
Q
What is molluscum contagiosum?
A
- Benign, usually self limiting disease in children (1-5 yrs),
- Rare in adults, but may be present in genital area where it may be transmitted sexually
20
Q
Cause of molluscum contagiosum?
A
- Cause: pox virus
- Incubation period: 2- 8 weeks
- Transmission: person to person, autoinnoculation
21
Q
Clinical features of molluscum contagiosum?
A
Presents with discrete dome shaped papules with a umbilicated center from which a cheesy plug can be expressed
22
Q
Common sites of infection for molluscum contagiosum?
A
face, eyelids, neck axillae, thighs, genital regions
23
Q
What is eczema molluscum?
A
eczema and erythematous changes around lesions
24
Management of molluscum contagiosum?
1. Watchful waiting (in the immunocompetent)
- since they are generally benign and self limiting.
2. Treatment:
- Curettage
- Cryotherapy
- Immiquimoid cream (Aldara)
25
What is pityriasis rosea?
- Common, acute, self-limited eruption that is believed to be caused by HHV7 or HHV6.
- Generally asymptomatic, and spontaneously resolves in 2 – 10 wks
26
Clinical features of pityriasis rosea?
1. Some patients have flu-like symptoms; fever, tiredness, general malaise, arthralgia.
2. Classically, one truncal, ‘herald’ or ‘mother’ patch preceeds other lesions by several days to weeks in 50-90 % of patients.
- Is rounder, redder & scalier than the 2ndry patches
3. Subsequent lesions form in crops, are smaller and align along cleavage lines at the back
‘christmas tree’ pattern
27
Ddx for pityriasis rosea?
1. Always rule out secondary syphilis
2. T. Corporis
3. Guttate psoriasis
4. Drug reaction
28
Treatment of pityriasis rosea?
1. Generally none required
- Reasurance and patient education
2. Topical steroids if itch.
29
What is chicken pox?
- Highly contagious disease caused by primary infection with VZV
- in temperate regions, largely affects children <10; in tropics: teenagers
- transmission is by direct contact with lesions of CP or HZ persons or by respiratory route. (IP 15 dys)
- Patients infectious 4 days before and 5 days after appearance of rash i.e until all lesions have crusted
Note: Lifelong immunity follows infection, unless in immunosuppression
30
Clinical features of chicken pox?
1. Characterized by clear vesicles on erythematous base (‘dew drops on a rose petal’) on scalp, face, mouth and trunk
2. Begin as red macules that rapidly (within 24 hrs) develop into papules, vesicles & pustules,
- later umbilicate & crust, to heal without scarring (unless infected)
- often new lesions arise for 4 dys, crusting by dy 6
31
Key feature of chicken pox?
lesions in all stages of devpt in a given region of the body
i.e. erythema, papules, vesicles, pustules, crusts all at once!
- Commonly associated with prodrome: fever, malaise, arthralgia
32
Complications of chicken pox?
1. Pneumonia, myocarditis, encephalitis, meningitis esp in adults
2. Reye’s syndrome: hepatitis and acute encephalopathy in children who receive aspirin for varicella symptoms
- NO Aspirin in chicken Pox!!
33
Management of chicken pox?
1. Strict isolation
2. Self limiting in children and decision to treat be made on case to case basis
- Acyclovir 20mg/kg (max 800mg)5x daily for 5 days
- AVOID aspirin for fever
2. Rx recommended in adults and adolescents as have more severe course with more complications
- Acyclovir 800mg 5x/dy for 5 days.
3. More effective if given within 24 hrs.
4. ALL immunosuppressed patients must be treated regardless of age and time of presentation.
34
What is herpes zoster?
- Characterised by painful, small grouped vesicles on an inflamed base.
- Usually localised to a dermatome without crossing midline.
- A result of reactivation of latent HHV 3 (VZV infection) from prior chicken pox.
- Not as contagious as CP but possible to transmit CP in those previously not exposed
35
Epidemiology of herpes zoster?
Incidence increases with age and immunosuppression
1. Below 45 yrs: annual incidence is 1/1000
2. Above 70 yrs: is 4x greater
3. HIV infected individuals: 30/1000/yr
36
Most common affected dermatomes in herpes zoster?
1. Thoracic (55 %)
2. cranial (20 %, trigeminal the most common)
3. lumbar (15 %)
4. sacral (5 %)
37
Clinical features of herpes zoster?
1. usually preceded by prodrome of fever, headache & localised intense pain & parasthesia
2. erythematous papules & plaques develop in the dermatome, which later form blisters.
3. become pustular, crusted, and heal in 2 – 3 wks
- May be longer in old age & and immunosuppression
4. new lesions continue to appear for 1-5 days after first eruption.
38
Describe the relationship between HIV and herpes zoster?
- HZ one of earliest manifestations of HIV
- Associated with mean CD4 of 400 μL-1
- HZ found to have 70 % PPV for HIV in SS Africa
- Greater severity of pain and longer duration than in the immunocompetent
39
What is post-herpetic neuralgia?
localized pain persisting for at least three months after the acute inflammatory phase of acute zoster on the skin.
> 50% of adults >50yrs with HZ have PHN*
40
3 typs of pain in post herpetic neuralgia?
The pain can be of three types
1. Triggered pain
- pain after normally non-painful stimuli eg touch, or
- mild pain stimulus causing massive pain sensation
2. Constant monotonous dull aching pain
3. Shooting, neuritic pain
41
Cause of post herpetic neuralgia?
- Believed to be due to persistent discharge & hyperexcitability of the nerves due to damage following the acute zoster.
- Can therefore be prevented by early initiation of treatment for zoster.
42
Complications of herpes zoster?
1. opthalmic involvement
2. motor involvement
3. Ramsay Hunt syndrome
4. disseminated HZ
43
Opthalmic involvement in HZ?
In 76 % of cases, vesicles on the tip and side of the nose portend eye involvement (Hutchinson’s sign) vs 34 % without.
44
Motor involvement in HZ?
- S3 involvement: urinary hesitancy, retention
- T6-sacral: bowel ostruction
45
Ramsay Hunt syndrome in HZ?
1. Facial paralysis
2. herpes on external ear or eardrum
3. auditory symptoms (tinnitus, vertigo, deafness etc)
46
Disseminated HZ?
- >20 vesicles outside the affected dermatome.
- Visceral involvement: lungs, CNS
47
Management for HZ?
1. Rule out HIV.
2. For pain: NSAIDS, antidepressants
3. Antibiotics for infected, crusted lesions.
48
Treatment for HZ?
Preferably within first 72 hrs of rash
1. Acyclovir 800 mg 5x/dy for 7-10 days OR
2. Famciclovir 500mg 3x/dy) OR
3. Valacyclovir 1000mg 3x/dy
4. Consider IV treatment in: eye involvement, RHS, Disseminated HZ
49
What are the herpes simples infections?
1. HSV 1
- Mostly affects oro-labial area
- About 50 % of infected pple are asymptomatic
2. HSV 2
- Responsible for Genital area herpes
- 20 % completely asymptomatic
Note: Changes in sexual habits has seen each of the two viruses commonly infecting either site.
50
Epidemiology of hepres simplex infections?
Common in HIV patients with low CD4 counts
- HSV should be considered for all ulcerative & nonhealing lesions anywhere on the body of HIV-infected persons.
51
HSV is clinically classified as?
Since most initial infections are asymptomatic, clinical disease better classified as
1. First episode: either real primary infection or recurrent by clinically manifesting for 1st time
2. Recurrent episode: preceded by prior clinical eruptions
52
Characteristic features of HSV infections?
1. Infections are lifelong.
2. Primary infection followed by viral axonal spread to nucleus from where continuous apperance to other sites occurs
3. Lesions are very painful, self-limiting .
53
Clinical features of oro-labial herpes?
Manifests as gingivostomatitis or herpes labialis.
- Acute Gingivostomatitis: broken vesicles that appear as erosions/ulcers covered with white membrane.
- Oral mucosa, tongue, tonsils, but may extend to involve pharynx.
- Untreated lasts for 1-2 weeks
54
Clinical features of recurrent herpes labialis?
aka cold sore, fever blisters
- Recurrent HSV 1 responsible 95 % of the time.
- Typically present as grouped blisters on erythematous base ± lip swelling, later pustules & ulceration
- Lips common site, but any site possible; cheeks, eyelids, earlobes.
- Prodrome of tingling, itching or burning may ocur.
- headance, fever, nasal congestion not unusual.
- Sun exposure (UVB) frequent trigger.
- 2-3 recurrences/yrs
55
What is herpes gladiatorum?
on the neck, side of the face and forehead of persons wrestling with infected individual.
56
What is herpetic whitlow?
- infection of fingers and periungual area.
- begin as tender erythema on lateral nail fold or palm, b4 deep blisters aft 24-48 hrs.
57
What is eczema herpeticum?
- HSV 1 infection of skin of mostly Atopic Dermatitis pts.
- also seborrhoeic dermatitis, pemphigus, Darier’s etc
- small vesicles mostly within original dermatitis
- soon enlarge, umbilicate , form pustules and crust
58
Herpes in immunosuppression?
- high risk of reactivation, hence more severe, more persistent and more recurrent episodes.
- as a rule, any erosive mucocutaneous lesion should be considered herpes until otherwise proven
- Lesions typically erosions or crusts; vesicles may be missed.
59
Describe genital herpes?
- Transmitted by skin-skin contact, usually during sex.
- Many cases asymptomatic
- viral shedding can take place in between symptomatic episodes.
- even normal appearing skin can shed viral particles.
60
Clinical features of genital herpes?
- Typical grouped blisters on erythematous base
- New such blisters continue to form over 7-14 dys (2-3 dys if recurrent episode)
- Duration: 3 wks or more (primary episode), ~7dys (recurrent episode).
61
Treatment for herpes simplex infections?
1. acyclovir
2. famciclovir
3. valacyclovir
