Infectious Disease Flashcards
1
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A
Cellulitis
- GAS and S. aureus = adults
- HIB = in children <3 yo
- 4 factors:
- erythema/hyperpigmentation
- warmth
- Edema
- pain
- Diagnosis in immunocompromised host:
- skin cx
- aspirate/blood cx
- mild leukocytosis with left shift and a mild increased sed rate
-
tx: empiric
- cephalexin (keflex)
- non-betalactam
- clindamycin
- tetracycline
- elevate lower legs
- cold compresses for pain
- send to hospital if at risk for systemic disease
2
Q

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Erysipelas
- **STREAKING**, does not involve the deeper layer (subcutaneous tissue)
- caused by GAS and s.aureus in adults, HIB in children <3 yo
- 4 factors:
- 1.erythema
- 2.warm
- pain
- 4.edema
- Diagnosis:
- in immunocompromised host:
- skin cx, aspirate/blood cx
- Mild leukocytosis with a left shift, and a mild increased sed rate
- in immunocompromised host:
- tx: treat empirically
- cephalexin (keflex)
- non-beta-lactams
- clindamycin or tetracycline
- elevate legs and cold compresses
- send to hospital if at risk for systemic infection
3
Q

A
Impetigo
- **caused by Staph**
- erythema and Honey crusted
- diagnosis:
- gram stain and cx
- tx:
- acute: mupirocin ointment 2-3x/day for 10-14 days
- oral abx:
- cephalexin if concern for MRSA: doxycyline, clindamycin or BActrim
4
Q
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5
Q

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bullous impetigo
- Caused by S.aureus
- favor trunk, can have fever and diarrhea
- tx: mupirocen 2-3x/day for 10-14 days
- oral:
- cephalexin
- if concern for MRSA: doxycyline, clindamycin, or bactrim
- RECURRENT:
-
mupirocen BID for 2-3 weeks
- wash the area with CLN cleansers or dilute bleach baths ( 1/2 cup in a full bath)
-
mupirocen BID for 2-3 weeks
- oral:
6
Q

A
Furuncle/Abscess
- furuncle involves hair follicle, abscess does not
- **causative agent: S. aureus**
- firm, fluctuant mass, painful to touch
- exudes from the surface, with purulent material
- diagnosis:
- clinical, can cx if needed
- tx: I&D with warm moist compresses as well
7
Q

A
Pitted keratolysis
- **caused by corynebacterium minutissimum (gram positive bacilli) **
- tends to erupt on weight bearing surfaces and common in pts with hyperhidrosis
- diagnosis:
- clinical
- tx:
- promote dryness
- topical clindamycin or erythromycin (BID)
- wash feet with BPO wash
8
Q

A
Erythrasma
- **causative agent is Corynebacterium minutissimum** (gram positive bacilli)
- reddish, brown patch that is uniformly scaly
- non-inflammatory border and no advancing border
- not very pruritic
- Diagnosis:
- Wood’s lamp: coral-red fluorescence
- want to do KOH to r/o fungal
- tx:
- decrease moisture
- topical clindamycin or erythromycin
9
Q

A
Candidiasis
- satellite pustules
- **affects the scrotum**
- erythematous patch
- **causative agent candida albicans**
- Diagnosis:
- KOH wet prep
- Tx:
- ketoconazole 2% cream, fluconazole daily for 2-4 weeks
- Mucosal:
- clotrimazole trouch 5x/day
- Nystatin swish and swallow
- oral fluconazole
10
Q

A
Tinea Corporis
- **causative agent: Trichophyton rubrum and Trichophyton mentagrophytes**
- Annular, scaly borders, advancing, erythematous
- Diagnosis:
- KOH wet prep
- Fungal Cx
- tx:
- Ketoconazole 2% cream (imidazoles) or Terbinafine 1% cream (allyamine)
- oral:
- fluconazole
- terbinafine (for tinea unguium 250 mg QID for 6-12 weeks vs once weekly for 52 weeks)
11
Q

A
Tinea Incognito
- **causative agent: Trichophyton rubrum and Trichophyton mentagrophytes**
- Annular, scaly borders, advancing, erythematous
- Diagnosis:
- KOH wet prep
- Fungal Cx
- tx:
- Ketoconazole 2% cream (imidazoles) or Terbinafine 1% cream (allyamine)
- oral:
- fluconazole
- terbinafine (for tinea unguium 250 mg QID for 6-12 weeks vs once weekly for 52 weeks)
12
Q

A
Tinea Cruris
- **causative agent: Trichophyton rubrum and Trichophyton mentagrophytes**
- Annular, scaly borders, advancing, erythematous, does not affect the scrotum
- Diagnosis:
- KOH wet prep
- Fungal Cx
- tx:
- Ketoconazole 2% cream (imidazoles) or Terbinafine 1% cream (allyamine)
- oral:
- fluconazole
- terbinafine (for tinea unguium 250 mg QID for 6-12 weeks vs once weekly for 52 weeks)
13
Q

A
Tinea Manuum
- **causative agent: Trichophyton rubrum and Trichophyton mentagrophytes**
- Tinea manum: “one hand, two feed syndrome”
- Diagnosis:
- KOH wet prep
- Fungal Cx
- tx:
- Ketoconazole 2% cream (imidazoles) or Terbinafine 1% cream (allyamine)
- oral:
- fluconazole
- terbinafine (for tinea unguium 250 mg QID for 6-12 weeks vs once weekly for 52 weeks)
14
Q

A
Tinea Pedis
- interdigital, moccasin,inflammatory (vesicular)
- **causative agent: Trichophyton rubrum and Trichophyton mentagrophytes**
- Diagnosis:
- KOH wet prep
- Fungal Cx
- tx:
- Ketoconazole 2% cream (imidazoles) or Terbinafine 1% cream (allyamine)
- oral:
- fluconazole
- terbinafine (for tinea unguium 250 mg QID for 6-12 weeks vs once weekly for 52 weeks)
15
Q

A
Tinea Faciei
- unilateral erythematous face rash
**causative agent: Trichophyton rubrum and Trichophyton mentagrophytes**
- Diagnosis:
- KOH wet prep
- Fungal Cx
- tx:
- Ketoconazole 2% cream (imidazoles) or Terbinafine 1% cream (allyamine)
- oral:
- fluconazole
- terbinafine (for tinea unguium 250 mg QID for 6-12 weeks vs once weekly for 52 weeks)
16
Q

A
Tinea Capitis
**causative agent: Trichophyton rubrum and Trichophyton mentagrophytes**
- Tinea capitis: requires oral tx with griseofulvin plus topical medicated shampoo (ketoconazole 2% shampoo)
- Diagnosis:
- KOH wet prep
- Fungal Cx
- tx:
- Ketoconazole 2% cream (imidazoles) or Terbinafine 1% cream (allyamine)
- oral:
- fluconazole
- terbinafine (for tinea unguium 250 mg QID for 6-12 weeks vs once weekly for 52 weeks)
17
Q

A
Tinea Versicolor
- **caused by Malassezia furfur**
- risk factors: high temps and humidity
- Multiple brown, tan, or pink oval to round macules/patches or thin plques with subtle scales
- common in upper trunk/shoulders
- can be hyper/hypopigmented
- diagnosis:
- KOH wet prep
- Wood’s Lamp: ywllo-green fluorescensce
- DDx post-inflammatory hypo/hyperpigmentation
- tx: ketoconazole 2% shampoo
- OTC selenium sulfide or zinc shampoos
- pt ed:
- may take months for pigment to return
-
this is a chronic condition
- weekly maintenance therapy
18
Q

A
Lice
- caused by **Pediculus humanus capitis**
- erythema, scaling, excoriations, lymphadenopathy
- High yield locations: above the ears and lower occipital scalp
- Diagnosis:
- clinical
- Tx:
- Permethrin shampoo = first line
- Malathion = second line
- Ivermectin ⇒ DO NOT GIVE TO CHILDREN <15kg
- 7 days in bag or washed in HOT water
19
Q

A
Scabies
- caused by Sarcoptes scabiei hominis
- mite lives in the stratum corneum
- severe pruritus worse at night/ in shower
- Diagnosis:
- delta-wingjet sign
- Biopsy: but difficult to capture the organism
- Mineral Oil Prep: very time consuming
- Tx:
- Permethrin 5% applied before bed twice, separated by one week
- 10 days of storage for clothing/bedding or washed in HOT water
- pt ed:
- pruritus and lesions will last 2-4 weeks after tx
20
Q

A
Condyloma accuminatum
- Causative agent: **HPV**
- tiny, painless papules that evolve into soft, fleshy cauliflower-like (barnacle like) lesions
- Diagnosis:
- clinical or serologies
- Tx:
- 80% resolve on their own
- salicylic acid
- cryotherapy (liquid nitrogen)
- electrocauterization or surgical remove
- Prevention: HPV vaccine
21
Q

A
Herpes Simplex Virus
- dsDNA virus
- small round vesicle on erythematous base
- PAINFUL, burning grouping of vesicles
- may become umbilicated or pustular
- then experience erosion/ulceration and crust with scalloped border
- diagnosis:
- Viral cx :but sensitivity = 50%
- PCR: higher sensitivity than cx
- Tzank smear = multinucleated giant cells
- tx:
- valacyclovir
- acyclovir
- protection from sun
- consider prophylaxis
22
Q

A
Verrucae vulgaris
- warts caused by HPV (dsDNA)
- hyperkeratotic dome shaped papules or plaques with punctated black dots (thrombosed capillaries)
- diagnosis:
- clinical
- serologies
- tx: 80% will resolve on their own
- salicylic acid
- cryotherapy
- electro cauterizatiion/surgery
- prevention:
- HPV vaccine
23
Q

A
Verrucae planae
- flat warts, made worse by shaving
- caused by HPV (dsDNA)
- diagnosis:
- clinical
- serologies
- tx: 80% will resolve on their own
- salicylic acid
- cryotherapy
- electro cauterizatiion/surgery
- prevention:
- HPV vaccine
24
Q

A
Verrucae vulgaris
- plantar/palmar warts: tender to pressure
- diagnosis:
- clinical
- serologies
- tx: 80% will resolve on their own
- salicylic acid
- cryotherapy
- electro cauterizatiion/surgery
- prevention:
- HPV vaccine
25
Q

A
Molluscum contagiosum
- caused by **DNA poxvirus**
- spread via skin2skin contact
- tends to appear near skin folds, lateral trunk, thighs, buttocks, genitals and FACE
- diagnosis:
- clinical diagnosis
- serologies
- tx:
- should spontanously resolve in immunocompetent patients
- tx underlying eczema
- encourage daily skin hydration
- cantharidin = creates more inflammation which triggers an immune response
- can do curettage (VERY PAINFUL)
- cryotherapy
- retinoid
26
Q

A
Herpes Zoster
- aka shingles
- Hutchinson’s sign: involvement of CN V1 = urgent referral to OPTHALMOTHOLOGIST
- diagnosis:
- often clinical
- viral PCR or viral cx from a new vesicle
- tx: acyclovir or valacyclovir ASAP
- pt ed:
- may have post-herpetic neuralgias
- tx: gabapentin, tricyclic antidepressants, lidocain patches
- may have post-herpetic neuralgias
27
Q

A
Fifth’s Disease
- **caused by Parvovirus B19** ssDNA aka slap cheek
- erythema infectiosum
- Bright red, macular erythema on cheeks 7-10 days after prodromal sxs
- lacy, reticulated pattern of erythematous macules favors extremities > trunk
- diagnosis:
- clinical
- tx:
- supportive care
- complications:
- hydrops faecalis
- arthralgias of the small joints of the hands
28
Q

A
Hand, Foot and Mouth Disease
- caused by **coxsackievirus A16**
- ssRNA virus
- Enterovirus A71: much more severe, can be fatal
- msot common in summer and fall
-
onychomadesis:
- fingernails/toenails fall off 1-2 months later (especially with coxsackie virus A16)
- diagnosis:
- clinical
- tx:
- resolves within 1-2 weeks
- complications:
- otitis media
- pneumonia
- encephalitis
29
Q

A
Measles
- aka rubeola caused by RNA paramyxovirus (ssRNA)
- Prodromal sxs:
- cough, coryza, conjunctivitis
- fever
- Koplik spots
- exanthem that spreads cephalocaudally
- Morbillaform rash
- diagnosis:
- clinical
- serologies
- Tx:
- supportive