Viral disorders Flashcards
What virus causes warts?
HPV
Explain the pathophysiology of HPV and warts
The virus incorporates itself into the basement membrane of the epidermis. As it moves up through the layers, the virus differentiates and begins to replicate. Lesions form and can cause more lesions in the surrounding area.
True or false: cutaneous warts are more common in children?
true
What are the different types of warts?
- common warts
- filiform warts
- flat warts
- plantar warts
- condylomata acuminate
Describe the common wart
- fingers, hands, and other areas
- single wart or groups
- rough scaly appearance
Describe the filiform wart
- face and neck
2. thin, soft, and slender
Describe the flat wart
- face, hands, and lower legs
2. flat papules, with little to no scale
Describe the plantar wart
- bottom of feet
- pain with lateral pressure
- elevated or flat and hyperkeratotic
Describe condylomata warts?
- soft, friable, vegetating clusters
2. asymptomatic
What factors determine the treatment of warts?
- type
- location
- size
- amount of distress
What are the first line treatments of common and plantar warts?
- electrodesiccation and curettage
- cryotherapy with liquid nitrogen
- salicylic acid
What are the second line options for common and plantar warts?
- Imiquimod
- duct tape
- podofilox
What are the treatment options for condylomata acuminata?
- podofilox
- podophyllin
- imiquimod
- liquid nitrogen
- trichloroacetic acid
What are the adverse effects of podofilox?
- burning (s > g)
- pain (s > g)
- inflammation (s > g)
- itching (s > g)
- erosion (g > s)
- bleeding (g)
What is the mechanism of action of podofilox?
antimitotic agent
What are the two strengths of imiquimod?
5% and 3.75%
What is the mechanism of action of imiquimod?
immune response modifier that activates cytokine response
What is the warning associated with imiquimod?
Increased chance of sunburn
What are the adverse reactions of imiquimod?
erythema, erosion, burning, excoriation/flaking, and edema
What is the treatment algorithm for head lice?
- confirm diagnosis
- nonpharm + permethrin 1% or other pyrethrin combo
- other pyrethrin combo or malathion or benzoyl alcohol
- ivermectin or spinosad with or without TMP/SMX
What is the first line treatment for pubic lice?
pyrethrins with piperonyl butoxide or permethrin
What is the pathophysiology of scabies?
Mites live 3-7 days away from host. Female burrows through the stratum corneum and lays eggs. They hatch 10 days later and travel to skin surface to mature
What are the signs and symptoms of scabies?
- pruritus
- thread-like burrows
- excoriations
- eczematous dermatitis
- crusting
What are the first line treatments for scabies?
permethrin 5% cream or oral ivermectin
When is ivermectin not recommended?
In children < 15 kg or pregnant women
What are the indications for pyrethrins?
head, body, and pubic lice
What is the MOA of pyrethrins
interferes with neural transmission and piperonyl butoxide augments the activity of pyrethrins by inhibiting metabolism of pyrethrins
When are pyrethrins contraindicated?
When patients have allergies to ragweed, chrysanthemums, or other pyrethrin products
What is the MOA of permethrin?
acts on neural cell membranes delaying repolarization
What are the warnings associated with permethrin?
worsening asthma and photosensitivity
What are the adverse effects of permethrins?
pruritus, erythema, rash of the scalp, burning, stinging, and tingling
What is the MOA of spinosad?
CNS stimulant that produces louse neuronal excitation, paralysis, and death
What are the adverse effects of spinosad?
application site erythema and skin irritation
Which version of ivermectin is FDA approved?
The new topical agent for lice
What is the MOA of ivermectin?
It is an antihelminthic agents
What are the warnings associated with oral ivermectin?
postural hypotension, mortality in long term care residents
What are the adverse effects of ivermectin?
peripheral edema, tachycardia, GI SE, and transaminase elevations
What is the MOA of malathion?
ovicidal agent
When is malathion contraindicated?
In children less than 2 years old
What is the adverse effect of malathion?
irritation of scalp and skin
What is the MOA of lindane?
CNS stimulant that produces seizures and death of mites
When is lindane contraindicated?
in neonates (warning in children < 50 kg)
What is the black box warning on lindane?
neurotoxicity
What are the adverse effects of lindane?
fertility impairment, use with other drugs that lower seizure threshold
When do you add on TMP/SMX to permethrin?
if nits and lice are found 2 weeks after first course of therapy
