Viral infections Flashcards
1
Q
Herpes simplex virus
- definition
- diagnosis
- treatment
- prevention
A
- common viral infection by HSV-1 (oral and facial infections) or HSV-2 (genital and rectal infections)
- Tzanck smear, direct fluorescent Ab testing, PCR
- local (antiseptic), anti-viral drugs (acyclovir)
- avoid triggering factors, limit sex, avoid contact with other people, wash hands
2
Q
Herpes simplex virus
-pathogenesis
A
- Inoculation - virus enters the body
- Neurovirulence - virus inoculates and replicates in nerve cells
- Latency - after primary infection, virus remains dormant in ganglion neurons
- Reactivation - triggered by immunodeficiency, stress, trauma –> clinical manifestations
- Dissemination –> infection spreads to unusual sites
3
Q
Labial herpes
- pathogen
- clinical features
A
-HSV-1
- fever, enlarged LN, vesicles + ulcers on the mouth, swollen gums and easy bleeding
- prodromal symptoms: pain, tingling, burning
4
Q
Genital herpes
- pathogen
- clinical features
A
-HSV-2
- most patients are asymptomatic
- genitals: redness, swelling, tingling, pain, pruritus
- painful lymphadenopathy in the groin area
- vesicles, ulcers
5
Q
Herpes zoster
- definition
- diagnosis
- treatment
- prevention
A
- localized (dermatomal) blistering and painful rash, caused by reactivation of varicella zoster virus
- Tzanck smear (multinucleated giant cells in fluids of vesicles), PCR, skin biopsy
- acyclovir, rest and pain relief, emollients, oral antibiotics to secondary infection
- ASPIRIN SHOULD NOT BE USED
-vaccine
6
Q
Herpes zoster
- pathogenesis
- risk factors
A
Usually.
- primary infection: varicella (chickenpox), virus remains dormant in dorsal root ganglia
- reactivates and migrates down sensory nerves to the skin to cause herpes zoster
-UV, cold, stress, infection, immunosuppression, contact infection, radiotherapy at level of affected nerve root
7
Q
Herpes zoster
-clinical features (5)
A
- confined to the area of involvement
- severe pain –> burning, throbbing, stabbing
- erythematous maculopapular rash –> vesicular lesions –> pustular lesions –> crusting
- regional lymphadenopathy
- post-herpetic neuralgia –> confined to original dermatome, slow resolution, particularly in elderly
8
Q
Warts
- definition
- pathogenesis
- risk factors
- classification (5)
A
- hyperkeratosis and hyperplasia of epidermis, commonly caused by HPV
- skin-skin contact or autoinoculation
- children, atopic eczema, warm/ humid areas, immunosuppression
- common (verruca vulgaris), plantar (verruca plantaris), plane (verruca plana), filiform, mucosal
9
Q
Warts
- clinical features
- diagnosis
A
- firm, rough, papule or nodule
- black dot in the middle –> thrombosis of blood vessels
-clinical signs, skin biopsy, dermatoscope - homogeneous red dots on papilliform surface
10
Q
Clinical features of:
- Common warts
- Plantar warts
- Plane warts
A
- papules with a rough, hyperkeratotic surface (white), 1cm or larger, most often in back of fingers or toes
- on the soles of foot, painful, covered by callus with dark punctuate spots, mosaic warts (plaques that compromised multiple warts)
- smooth, flat-topped papules or nodules, common sites are face and dorsal aspect of hands and shins, FLESH- colored
11
Q
Clinical features of:
- Filiform warts
- Mucosal warts
A
- commonly appear on the face, raised, finger like projections
- oral warts affect the lips, inside the cheeks, may be called squamous cell papilloma
12
Q
Warts
- treatment
- prevention
A
- topical: salicylic acid
- surgical: curettage, cryosurgery, laser or electro surgery
-vaccines for HPV infection
13
Q
Molluscum contagiosum
- definition
- risk factors
A
- localized skin infection caused by molluscum contagiosum virus –> causes clusters of epidermal papules
- children, atopic eczema, warm/humid areas, immunosuppression, sexually active individuals
14
Q
Molluscum contagiosum
-pathogenesis
A
-virus infects the epidermis and replicates in the cytoplasm
-cellular proliferation –> lobulated epidermal growth that compress epidermal papillae
-basal layer remains intact
-cells at the core are destroyed –> large hyaline bodies form containing cytoplasmic masses of virus
material
15
Q
Molluscum contagiosum
-clinical features (5)
A
- small, firm, pearly pink umbilicated papules
- filled with a thick, white substance that is cheesy or waxy
- are painless, sometimes can itch
- scratching or picking can spread the virus
- it can be anywhere EXCEPT palms and soles
