Derm Pharm Exam 2 Flashcards
Pathogens causing cellulitis?
Staph aureus* (MSSA, MRSA, CA-MRSA)
Anaerobes
Gram + cocci
Gram - bacilli
Strep pyogenes
How is cellulitis diagnosed?
Blood culture is positive in only 30% of cases
What are some methods to approach cellulitis treatment?
- Mark margins before treatment
- Start empiric therapy
- Definitive therapy if known source
- Antimicrobial therapy for 7-10 days
Regular cellulitis treatment if mild/early infection?
Dicloxacillin or Cephalosporin
*Erythromycin if penicillin allergy
Regular cellulitis treatment if more severe infection?
Nafcillin or ceftriaxone IV
MSSA and strep pyogenes cellulitis treatment?
Cephalexin, dicloxacillin, clindamycin (all oral)
What is an oral option for CA-MRSA (not severe) to treat cellulitis?
Clindamycin, Trimethoprim-sulfamethoxazole
Severe CA-MRSA cellulitis treatment?
IV Vancomycin (go to), Linezolid, Daptomycin
What are causative pathogens of folliculitis?
Staph aureus (most common)
CA-MRSA
Pseudomonas aeruginosa (most often with pools and hot tubs)
What are some things to remember about folliculitis treatment?
Antibiotics are usually not necessary for smaller boils and warm saline compresses can be used to promote draining
Where do furuncles typically occur?
areas of friction or perspiration
Where are carbuncles typically found?
usually on the back of the neck
Who is at an increased risk of carbuncles?
Diabetics
How should MSSA or Strep pyogenes furuncle/carbuncle be treated?
Antibiotic course 7-10 days:
Dicloxacillin
Cephalexin
Clindamycin
How should CA-MRSA furuncle/carbuncle be treated?
Clindamycin, T/S, Linezolid
*may require IV therapy with Vancomycin
Most common organisms for impetigo?
Strep pyogenes and staph aureus
How is impetigo spread/environment?
Hot/humid climate and close contacts
What are topical treatment options for impetigo?
Mupirocin ointment 3x per day for 7-14 days
What topical treatment for MSSA impetigo?
Retapamulin ointment 1% twice daily for 5 days
Impetigo systemic antibiotics?
Dicloxacillin, cephalexin, clindamycin, amoxicillin/clavulanate
Mupirocin MOA
inhibits RNA synthesis, gram + bacteria, Bacteriostatic at lower doses and bacteriocidal at higher doses
Retapamulin MOA
Inhibitis bacterial protein synthesis by binding to a unique site on ribosomal 50S unit
What is retapamulin limited to?
impetigo; alternative to mupirocin
What is important to note about retapamulin?
Has a distinct mechanism that targets specific cross-resistance with other antibiotics does not occur
Antibiotics that inhibit cell wall synthesis
Penicillins
cephalosporins
Meropenem
Vancomycin
Antibiotics that inhibit bacterial protein synthesis?
Macrolides
Linezolid
Clindamycin
Antibiotics that inhibit nuclein acid synthesis
Fluoroquinolones
Rifampin
Antibiotics that inhibit folic acid synthesis
sulfonamides
Trimethoprim
Antibiotic that inhibit free radical formation
Metronidazole
What bite is more likely to cause infection
Cat bites
What to consider when choosing empiric therapy for bite treatment
Based on the oral flora of the biting animal
Consider MRSA
Pasturella in 50% dog wounds and 75% cat wounds
When to use parenteral antibiotic for bite
Systemic signs of toxicity
Deep infection/osteomyelitis
Rapid progression of erythema
Progression after 48 hours of oral therapy
Proximity to an indwelling device
Non-pharm options for burn treatment
Cool the burned area
Avoid ice
Wash but do not scrub
Do not remove blisters less than 6mm and intact
Cover burns with dressings
When do you update tetanus when treating a burn?
greater than 1st degree burn
Pain management options for burn?
NSAIDs, topical diclofenac (not on open wounds) and last resort is opioids
First degree burns topical agents?
Aloe vera
Antibiotic ointments
Second degree burn topical agents?
Topical antimicrobial and occlusive dressing
Lyme disease symptoms
Bull’s-eye rash and flu-like symptoms
How to prevent tick bites?
Wear protective clothing
Routine antimicrobial prophylaxis NOT recommended
When should Lyme prophylaxis be considered?
Attached tick identified as I. scapularis for 36+ hours
within 72 hours of tick removal
Doxycycline 200mg orally once
CI in pregnancy and children <8 years old
Patient should be monitored for at least 30 days after the tick bite
Early Lyme disease treatment?
Doxycycline 100mg BID x 14 days
Children: Amoxicillin
Lyme meningitis/Neurological disease treatment?
Ceftriaxone 2 grams IV daily for 14 days or
Doxycycline 200-400 mg orally
Pediatrics: Ceftriaxone 50-75mg/kg/day IV
Lyme carditis treatment?
Parenteral therapy 14-21 days
Lyme arthritis treatment?
Oral antibiotics for 28 days
HPV wart notes?
Warts will regress but virus will progress
Cervical warts
Medical treatment for HPV wart treatment?
Liquid nitrogen
HPV non pregnant limited vaginal disease treatment?
Trichloroacetic acid, possible laser ablation
HPV non pregnant limited vulvular disease
Compliance with self therapy - Imiquimod
Non compliant - Trichloroacetic acid
Describe Trichloroacetic acid HPV treatment
Applied by healthcare provider
Can be used on vulva, vagina, and in pregnancy
Weekly application for 4-6 weeks
Large thick lesions may not respond
Describe imiquimod treatment for HPV
immune response modifier
Wash hands before and after application
How is Aldara applies for HPV
3 days per week for up to 16 weeks
How is Zyclara applied for HPV
daily for up to 8 weeks
HPV recurrence?
30% have a recurrence within 12 weeks
HPV vaccination?
Gardasil 9
Who can get Gardasil 9?
All male and female patient ages 11-12 through age 26 if not yet vaccinated
How should Gardasil 9 be administered?
Before HPV exposure
Not during pregnancy
When is HSV-1 developed?
Childhood
When is HSV-2 developed?
Sexually transmitted
What is the clinical presentation of HSV?
Mucocutaneous and Meningoencephalitis
How can HSV be treated?
Acyclovir and valacyclovir (against HSV-1 and HSV-2)
How is VZV transmitted?
aerosolized droplets or direct contact
When does VZV infectivity begin
48 hours before onset of rash and ends when all skin lesions have fully crusted
What us the clinical presentation of VZV?
Chickenpox
Shingles
Sever pain before lesion appears
Postherpetic neuralgia
Chickenpox treatment?
Antiviral not indicated for children
Acyclovir 800mg 5x daily for adults
IV acyclovir for immunocompromised
Shingles treatment?
Acyclovir 800mg 5 times daily x 7-10 days
Initiate within 72 hours
IV therapy if immunocompromised or severe
Acyclovir MOA?
Prodrug that requires activation
DNA synthesis is prevented w/o affecting normal host cell functions
What all can acyclovir treat?
HSV-1, HSV-2, VZV
Pharmokinetics of acyclovir?
Oral, IV, topical
Poor absorption
CSF penetration
What drugs interact withe acyclovir?
Cyclosporine
Sirolimus
Tacrolimus
Safety/education for acyclovir?
Treatment is not curative
Does not prevent spread
Precautions are necessary
What does valacyclovir turn into?
Acyclovir
What is the benefit of valacyclovir?
Liquid option
Greater availability than acyclovir
What type of vaccine is varicella zoster vaccine?
Live vaccine
Routine childhood vaccine - 2 doses
Who is Shingrix recommended for and how is it administered?
Recommended for immunocompromised adults >50 years old
2 doses separated by 2-6 months
Avoid in pregnancy
Zostavax?
No longer available
What to note about systemic fungal infections?
Invasive
Candida is responsible in 90% of cases
Two classes of antifungals and two in each class?
Imidazole - Ketoconazole and Clotrimazole
Triazole - fluconazole and itraconazole
Azole antifungal MOA?
Disrupts fungal cell membrane integrity
What species are Azoles effective against?
Candida, dermatophytes
NOT effective against Aspergillus
How are azoles offered?
IV, oral, topical
Absorption effects with different azoles?
Fluconazole - food no effect
Ketoconazole - variable
Itraconazole - INCREASED absorption with food
What azole crosses the BBB
fluconazole
Important drug interaction with azole?
They are CYP INHIBITORS
What are CYP substrates effected by azoles? (increased concentration)
Warfarin
Phenytoin
Carbamazepine
Cyclosporine
Tacrolimus
What will decrease the absorption of azoles?
Antacids
BBW of azoles?
itraconazole - CHF
ketoconazole - hepatotoxicity, QT prolongation
What to note about nystatin resistance?
Rare
Nystatin antifungal spectrum?
candida albicans
Pt. education with nystatin?
Do not eat or drink for 20 minutes after use
How to take nystatin with esophageal candidiasis?
swish and SWALLOW
How to take nystatin with oral candidiasis?
Swish and SPIT
How to treat mild oral candidiasis?
Clotrimazole troches
How to treat oral candidiasis moderate/severe/unresponsive to topical therapy?
Fluconazole 100-200mg
How to treat refractory oral candidiasis?
Nystatin suspension
Uncomplicated vulvovaginal candidiasis treatment?
Fluconazole 150mg x 1
How to treat vulvovaginal candidiasis with severe symptoms?
Fluconazole 150mg every 72 hours for 2-3 doses
How to treat recurrent vulvovaginal candidiasis?
Fluconazole 150mg every 72 hours for 2-3 doses + maintenance 150mg per week for 6 months
How to treat vulvovaginal candidiasis in pregnancy?
Topical clotrimazole or miconazole
What is first line treatment for topical antifungal infections?
Terbinafine 1%
When should systemic therapy be considered for fungal infections?
topical therapy failure
What are systemic antifungal treatment options?
Terbinafine
Itraconazole
Fluconazole
What is the gold standard treatment for onychomycosis?
Oral antifungal agents
What is the only topical option for onychomycosis?
Ciclopirox
What are some therapeutic options for diaper dermatitis?
Barrier preparations
Topical corticosteroids
Antifungal agents
What should be avoided for diaper dermatitis due to systemic toxicity risk?
Baking soda
What are some barrier ointment options for diaper dermatitis?
OTC - Petrolatum and zinc oxide
Rx - sucralfate
What are some antifungal agents for diaper dermatitis?
Nystatin and ketoconazole for candida
What is an example of mild to moderate treatment for diaper dermatitis?
Zinc oxide products
How to treat a bacterial superinfection caused by diaper dermatitis?
Topical or oral antibiotics
*oral only for very severe infections
