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Derm Exam 2 > Infections & Infestations > Flashcards

Infections & Infestations Flashcards

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1
Q

Condyloma acuminatum (Genital warts)

A

● Due to infection of genital or perianal skin
by the human papillomavirus (HPV)
○ HPV is the most common ST

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2
Q

HPV is transmitted from lesions during
_____

A

skin-to-skin contact.

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3
Q

Condylomata acuminata- most often caused by
HPV types ______

A

6 and 11

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4
Q

Condyloma acuminatum S/S

A

● Warts appear after a 1-6 month incubation
period
● Are normally asymptomatic but some
patients will have burning, itching, or
discomfort
● Usually soft, moist pink, white, light brown or
grey polyps (slightly raised lesions)

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5
Q

Condyloma acuminatum presentation in males

A

most commonly present under the foreskin,
on the coronal sulcus, within the urethral meatus, and on the penile shaft

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6
Q

Condyloma acuminatum presentation in females

A

most commonly present on the vulva, vaginal
wall, cervix, and perineum. Urethra and anal region may be affected

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7
Q

Condyloma acuminatum (Genital warts) diagnosis

A

● Clinical evaluation; sometimes
colposcopy/anoscopy
○ Magnification may be helpful
○ Differentiate between condyloma lata of
secondary syphilis and from carcinomas
○ Colposcopy → visualize the endocervical warts; May apply acetic acid to enhance visualization

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8
Q

Condyloma acuminatum (Genital warts) management

A

● Mechanical removal (liquid nitrogen
cryotherapy, electrocauterization, laser,
or surgical excision)
● Topical treatment
○ Podofilox (Condylox gel)
○ Imiquimod cream
● Recurrences are frequent and require
retreatment. There is no cure, just
management.

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9
Q

Condyloma acuminatum (Genital warts) prevention

A

● HPV vaccines (eg, Gardasil and Cervarix)
can prevent genital warts in males and
females
○ Indicated for youth ages 9-26, a
three shot series given over 6
months
Sex partners of people with genital warts
should be examined, and treated, if
necessary

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10
Q

Molluscum contagiosum

A

● A poxvirus infection of the skin characterized by discrete
umbilicated papules
● Very common in children

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11
Q

Transmission of Molluscum contagiosum

A

● Considered a sexually transmitted disease when
occurring in the genital area of adults
● Spread by wet skin-to-skin contact or autoinoculation

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12
Q

Molluscum contagiosum S/S

A

● Central umbilication of dome-shaped lesions
● Pink, dome-shaped, smooth, waxy, or pearly and umbilicated papules 2 to 5 mm in diameter, often arranged in clusters
● Children- commonly on the face, trunk, extremities
● Adults- commonly on the pubis, penis, or vulva

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13
Q

Molluscum contagiosum diagnosis

A

Clinical evaluation

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14
Q

Molluscum contagiosum treatment

A

● Often self-limiting in healthy patients
● Physical removal
○ Curettage
○ Cryosurgery- liquid nitrogen
○ Laser therapy
○ Electrocautery
● Topical irritants (eg, trichloroacetic acid, tretinoin, tazarotene, podophyllotoxin)
● Combination therapy may be helpful

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15
Q

Herpes simplex

A

● Herpes simplex viruses (1 and 2) commonly cause recurrent infection affecting the skin, mouth, lips, eyes, and genitals
○ Type 1- generally associated with ulcerative
oral infections
○ Type 2- generally associated with genital
infections
○ But NOT exclusively!
■ Type 1 genital infections and type 2 oral
infections are becoming more common

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16
Q

Herpes simplex presentation - two phases

A

○ Primary infection- the virus
becomes established in a nerve
ganglion
○ Secondary phase- recurrent
disease at the same site

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16
Q

______ → clusters of small
painful vesicles on an erythematous base

A

Mucocutaneous infections

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17
Q

Transmission of Herpes simplex

A

may be spread by respiratory
droplets, direct contact with an active
lesion, or contact with virus-containing fluid
(eg, saliva or cervical secretions)

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18
Q

Before visible lesions, patients will experience prodromal symptoms with ____

A

Herpes simplex

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19
Q

Course of herpes simplex lesions

A

● Grouped vesicles on an erythematous base appear
○ On mucous membranes, lesions accumulate exudate
○ On the skin, lesions form a crust
○ Lesions last 2-6 weeks and heal without scarring

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20
Q

Herpes simplex recurrent infection

A

● Virus is reactivated by local skin trauma (UV exposure, chapping, abrasion) or
systemic changes (menses, fatigue, fever)
● Recurrent infection is not inevitable
● Prodromal symptoms may be similar to the primary infection and last 2-24
hours
● Many people experience a decrease in frequency of recurrences,
some experience an increase

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21
Q

Herpes simplex Diagnosis

A

● Clinical evaluation
● Laboratory confirmation
○ PCR assay detects viral DNA
○ Serology can be performed on blood
specimens for identification of HSV 1 and 2

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22
Q

Herpes simplex treatment

A

● Oral acyclovir, valacyclovir, famciclovir
○ Start at first sign or symptom; is most
effective when started within 48 hours
○ Dosing will depend on initial episode vs.
recurrent episodes vs. suppressive therapy
● Topical agents for pain relief- tetracaine
cream, penciclovir cream
● Prevent spread to others
○ Avoid contact with open lesions; don’t
share drinks and razors; use condoms

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23
Q

the most common cause of genital ulcers in the industrial world

A

HSV

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24
Q

Varicella zoster (Herpes zoster, shingles)

A

● A cutaneous infection from the varicella-zoster virus (VZV)
○ It reactivates from its latent state in a posterior root ganglion, generally infecting a single dermatome
● Herpes zoster inflames the sensory root ganglia and the
skin of the associated dermatome

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25
Q

Varicella zoster (Herpes zoster, shingles) skin findings

A

● Pain, itching, burning localized to the dermatome; may precede eruption
by 4-5 days
● Normally one dermatome is affected, sometimes 1-2 adjacent dermatomes
● Eruption begins with red swollen plaques of various sizes, spread along the dermatome
● Vesicles arise in clusters from the erythematous base, contain cloudy, purulent
fluid by days 3-4

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26
Q

Varicella zoster (Herpes zoster, shingles)

A

● Clinical evaluation
● Tzanck smear can confirm
infection → will see multinucleated giant cells
● PCR or culture may differentiate
the virus

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27
Q

Varicella zoster (Herpes zoster, shingles)

A

● Symptomatic treatment
● Antivirals (acyclovir, famciclovir, valacyclovir)
○ Especially for immunocompromised
pts
○ Begin as soon as possible (<48 hrs)
● Analgesics are often necessary
● Wet dressings may help

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28
Q

Ophthalmic zoster (herpes zoster ophthalmicus)

A

● Involvement of any branch of the ophthalmic nerve
● Vesicles of the side of tip of the nose (Hutchinson’s sign) are associated
with the most serious ocular complications
● PO antiviral treatment results in decreased frequency of complications
Consult with ophthalmology!!

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29
Q

Postherpetic Neuralgia (PHN)

A

● Persistent or recurrent pain in the involved distribution lasting more than 30
days after the rash
● Pain is often severe, may be intermittent or constant, may be debilitating
● More common in the elderly

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30
Q

Postherpetic Neuralgia (PHN) management

A

● Can be difficult; there’s no reliable treatment
● Gabapentin, cyclic antidepressants (amitriptyline), topical capsaicin or lidocaine ointment
● Opioid analgesics may be necessary

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31
Q

Varicella zoster (Herpes zoster, shingles) prevention

A

● Immunocompetent adults (>50 years) should be given the recombinant
zoster vaccine (Shingrix)
○ Two IM doses, 2-6 months apart

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32
Q

Verrucae (warts) types

A

● Common warts (verruca vulgaris)
● Flat (plane) warts
● Plantar warts (verruca plantaris)

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33
Q

Common warts (verruca vulgaris)

A

● Warts are benign epidermal proliferations;
infects skin and mucous membrane
Skin Disease Diagnosis and Treatment, 4th edition. Habif and Dinulos;
Transmission: simple skin-to-skin contact, often
at sites with small skin breaks, abrasions, or
other trauma. Also, autoinoculation

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34
Q

Common warts
Skin Findings

A

● Flesh-colored papules evolve into
dome-shaped, gray to brown, hyperkeratotic,
discreet and rough papules
○ Black dots are thrombosed capillaries
● Common sites: hands/fingers, periungual
skin, elbows, knees, and plantar surfaces
● Filiform warts are finger-like projections;
often occur on the face
● Generally asymptomatic; occasionally itchy

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35
Q

f a wart on the hand,
periungual unit, or foot is
not resolving, it should be
biopsied to rule out ______
which can mimic a wart

A

squamous cell carcinoma

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36
Q

Common warts treatment

A

● OTC salicylic acid (most common)
○ Daily applications are needed
● Liquid nitrogen cryotherapy (most common)
○ May require several cycles of treatment
● Vinegar applications
● Imiquimod

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37
Q

To reduce your risk of common warts:

A

● Avoid direct contact with warts. This includes your own warts.
● Don’t pick at warts. Picking may spread the virus.
● Don’t use the same emery board, pumice stone or nail clipper on your warts as you use on
your healthy skin and nails. Use a disposable emery board.
● Don’t bite your fingernails. Warts occur more often in skin that has been broken. Nibbling
the skin around your fingernails opens the door for the virus.
● Groom with care. And avoid brushing, clipping or shaving areas that have warts. If you
must shave, use an electric razor.

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38
Q

Flat (plane) warts

A

● Benign cutaneous hyperproliferation, also due to HPV
● Common in children and young adults
● Spread locally through mildly traumatized skin
(shaving)

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39
Q

Flat (plane) warts Skin Findings:

A

● Pink, light brown, or light yellow papules- slightly elevated and flat-topped; 0.1 to 0.3 cm in size
● May be grouped or in a line
● Typical sites: forehead, back of hands, chin, neck, legs
● Generally asymptomatic

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40
Q

Flat warts treatment

A

Prognosis: may be very resistant to treatment
● Salicylic acid preparation, applied daily
● Imiquimod cream (high cost; off-label use)
● Tretinoin cream
● Liquid nitrogen (may not respond to
therapy)
● 5-fluorouracil cream

41
Q

Plantar warts (verruca plantaris)

A

● Frequently occur at points of
maximal pressure at the bottom of
feet, such as over the heel, toes,
heads of metatarsal bones
● A cluster of warts = “mosaic warts”

42
Q

Plantar warts
Skin Findings

A

● Round, single or multiple, coalescing,
flesh-colored, rough keratotic papules
● Punctate black dots are capillary loops
● May be tender with pressure
● Some warts are depressed,
resembling numerous small pits

43
Q

Plantar warts treatment

A

● Often difficult
● Therapy not required as long as they are
painless
● Keratolytic therapy with salicylic acid
● Imiquimod
● Blunt dissection
● Cryosurgery
● Vinegar applications
● Electrodesiccation/curettage
● Diluted intralesional cidofovir

44
Q

Cellulitis

A

● An acute infection of the dermis and subcutaneous tissue
○ Characterized by fever, erythema, edema, and pain
● Often caused by Group A beta-hemolytic strep/Strep pyogenes and Staph
aureus

45
Q

Cellulitis risk factors

A

● Risk factors include skin abnormalities (eg, trauma, ulcers, fungal
infections), diabetes, cirrhosis, poor lymph circulation, being malnourished
or immunocompromised. Also IV drug or alcohol abuse.
● Infection is most common in the lower extremities

46
Q

Cellulitis skin findings

A

● A spreading red, swollen, tender, or
painful area with an indefinite border
● Skin appears tight
● Palpation causes pain but rarely
crepitus
● Patient may have nausea, chills,
shaking
● May have regional lymphadenopathy
● Abscesses (collection of pus) may develop
if cellulitis worsens

47
Q

Cellulitis diagnosis

A

● Clinical examination
○ Skin will be red, warm, tender, and swollen
○ Borders are indistinct
● Mild to mod leukocytosis and slightly elevated ESR may be present
● If abscess is present, I&D and culture of drainage is helpful

48
Q

Cellulitis treatment

A

● Antibiotic
○ Nonpurulent cellulitis: dicloxacillin or cephalexin
○ High risk for MRSA cellulitis: TMP-SMX,
clindamycin, doxycycline, vancomycin
○ If severe, may require IV or IM antibiotics for 2-5 days
● Elevate affected limb
● Abscesses require drainage

49
Q

Erysipelas

A

● An acute, inflammatory form of cellulitis; more superficial than other
types and includes lymphatic involvement, “streaking”
● Margins are sharply demarcated
● Sudden onset of symptoms
● Usually infection of Group A Strep

50
Q

Often occurs on face and lower legs

A

Erysipelas

51
Q

Erysipelas course

A

Prodromal symptoms last for 4 - 48
hours and consist of malaise, myalgias,
chills, fever, and, occasionally,
decreased appetite and vomiting

52
Q

Erysipelas Skin findings

A

● Raised, clearly marginated borders
● Red, tender, and firm spots → deep red, hot, elevated shiny area
● Frequent lymphangitic streaking

53
Q

Erysipelas diagnosis

A

● Clinical evaluation
● Leukocytosis is common
● Blood culture (in toxic-appearing patients)

54
Q

Erysipelas treatment

A

● First line: penicillin V, dicloxacillin,
amoxicillin
● For patients with PCN allergies:
cephalexin, TMP-SMX, azithromycin or
clarithromycin
● Bed rest and elevation of affected limb
If the disease is severely advancing,
hospitalization and IV antibiotics are indicated.
Must treat promptly, otherwise death may result due
to systemic toxicity

55
Q

Folliculitis

A

● An infection and inflammation of hair follicles
● Often worsens with perspiration, trauma,
and friction
● May be infectious or noninfectious
○ Several types will be discussed shortly
● Common bacterial pathogens include:
○ Staph aureus
○ Pseudomonas aeruginosa → “hot tub
folliculitis”

56
Q

Gram-negative folliculitis

A

● An acneiform eruption worsens and becomes pustular
● Overgrowth can occur in people treated chronically with antibiotics
● Treatment with Isotretinoin

57
Q

Hot tub folliculitis (Pseudomonas folliculitis)

A

● Caused by Pseudomonas aeruginosa
● Occurs 1-4 days after bathing in a contaminated hot tub, swimming pool etc
● Often clears spontaneously, may require Cipro

58
Q

Mechanical folliculitis

A

● Results from chronic frictional exposure (ie wearing tight pants)

59
Q

Pseudofolliculitis

A

● A chronic problem, caused by ingrown hairs, most often at the neck; affects men
and women; common in people with tight, curly hairs; worsens with shaving
● Discontinue shaving; only cure is permanent hair removal

60
Q

Eosinophilic folliculitis:

A

● Pruritic, extensive papules suddenly appear on face, neck, chest
● Test for HIV; confirm testing with biopsy

61
Q

Occlusion folliculitis

A

● Results from occlusion (ie exposure to oil, greases, or occlusive ointments

62
Q

Folliculitis skin findings

A

● Dome-shaped pustules with small
erythematous halos arising in the
follicle
● Lesions are sometimes tender and itchy

63
Q

Folliculitis diagnosis

A

● Clinical diagnosis
● Culture not usually necessary
● May do a KOH exam to rule out other
conditions

64
Q

Folliculitis treatment

A

● If mild, may resolve without treatment
● Topical antibiotic therapy
○ Mupirocin
○ Clindamycin
● If severe, oral antibiotics may be required
○ Dicloxacillin
● If fungal, treat with oral antifungal
● Avoid heat, friction, and occlusion
● Antibacterial soap and warm, wet dressings may be helpful

65
Q

Furuncles and carbuncles

A

● A furuncle (“boil”) is a walled-off, deep and painful, firm or fluctuant mass
enclosing a collection of pus
● A carbuncle is an extremely painful, deep, interconnected collection of
multiple infected, abscessed follicles; comprised of several furuncles

66
Q

Most common organism in Furuncles and carbuncles

A

Staph aureus

67
Q

Furuncles and carbuncles S/S

A

-Any hair-bearing site can be affected; also, sites of high friction and sweating
-Common regions: waistline, anterior thighs, buttocks, groin, axillae

68
Q

Furuncles and carbuncles differences in skin findings & presentation

A

Furuncle:
● Red, swollen, and painful mass that drains at the surface
● Patient is afebrile
Carbuncle:
● Deep, tender, firm subcutaneous erythematous papules enlarge to nodules that
may be stable or become fluctuant
● Coalesces to form a larger mass with multiple draining points
● Malaise, chills, and fever may precede or occur during the height of inflammation

69
Q

Furuncles and carbuncles diagnosis

A

● Clinical diagnosis
● Culture of the lesion

70
Q

Furuncles and carbuncles treatment

A

● Incision and drainage for fluctuant lesions
○ Obtain specimen to send for culture
● Systemic antibiotics (should be effective against MRSA)
○ If multiple lesions or signs of systemic illness
○ TMP-SMX, clindamycin, doxycycline, dicloxacillin, or cephalexin
● Apply warm compresses to the area several times per day
● Caution - septicemia is a concern

71
Q

Recurrent furuncles and carbuncles- most commonly caused by _____. May
require daily washing with chlorhexidine or bleach solution

A

MRSA

72
Q

Impetigo

A

● A common, highly contagious, skin
infection of the epidermis
○ Staph aureus (80% of cases)
○ Strep pyogenes

73
Q

Impetigo: two types

A

nonbullous impetigo (most
common form) and bullous impetigo

74
Q

Impetigo Skin Findings: Bullous

A

flaccid bullae with clear yellow fluid,
later becomes darker; ruptured bullae leave a
thin brown crust. Fewer lesions and on the trunk more frequently than non-bullous impetigo

75
Q

Impetigo skin findings: non-bullous

A

most common form; lesions
begin as papules, progress to vesicles, then
pustules that enlarge and break down to
form thick golden crusts. Usually occur on
face and extremities. Honey-colored crusts.

76
Q

Impetigo diagnosis

A

● Clinical evaluation
● May gram-stain or culture lesions to
confirm diagnosis

77
Q

Impetigo treatment

A

Course is self-limiting, but if untreated, may spread and lasts for weeks to months
● Topical antibiotic ointment (for limited skin
involvement)
○ Mupirocin
○ Retapamulin
● Oral antibiotics (for widespread impetigo)
○ Cephalexin (or Doxycycline)
● Soaks and scrubbing can be beneficial

78
Q

Candidiasis

A

● A skin and mucous membrane infection with Candida species, most commonly
Candida albicans
○ A yeast that is part of normal skin flora but is an opportunistic pathogen
● Most commonly in skinfolds, digital web spaces, genitals, cuticles, and oral
mucosa

79
Q

Some predisposing factors for candidiasis include

A

● Obesity
● Immunodeficiency
● Hot, humid weather
● Altered flora resulting from antibiotic therapy
● Inflammatory diseases (eg, psoriasis) that occurs in
skinfolds
● Poor hygiene
● Tight-fitting clothing
● Infrequent diaper or undergarment changes
● Use of topical steroids

80
Q

Candidiasis
Skin findings:

A

● Intertriginous - red, moist, glistening plaques
with satellite pustules and papules with
fringes of white scale. Patches vary in size
and are pruritic.
● Oropharyngeal - causes white plaques on mucous membranes
that may bleed when scraped
● Vulvovaginal- causes pruritus and discharge

81
Q

Candidiasis diagnosis

A

● Clinical evaluation
● KOH prep from a pustule or scaly border will show spores and pseudohyphae - is diagnostic

82
Q

Candidiasis treatment

A

● Topical or oral antifungals
○ Fluconazole (PO if infection is severe or extensive)
○ Nystatin
○ Clotrimazole
■ (troches = an oral formulation)
● Keep affected regions dry

83
Q

Dermatophyte infections

A

● Fungal infections of keratin in the skin and nails
○ Tinea barbae- beard
○ Tinea capitis- scalp
○ Tinea corporis- body (“ringworm”)
○ Tinea cruris- groin
○ Tinea pedis- foot
○ Tinea unguium or onychomycosis - nail infection
● Dermatophytes are molds that require keratin for nutrition and must live on stratum
corneum, hair, or nails to survive

84
Q

Dermatophyte infections transmission

A

● Transmission occurs via direct skin contact with an infected individual or animal,
contact with fomites, or from secondary spread from other sites of infection (eg,
scalp, feet, etc)

85
Q

Dermatophyte infections predisposing factors:

A

● Moist, macerated skin
● Obesity
● Diabetes
● Exposure to animals
● Affected family members
● Topical corticosteroid use
● Immunosuppressed states
● Athletics

86
Q

Dermatophyte infections skin findings:

A

● Slightly raised border, papules and plaques with a rounded edge and white
scales; an advancing border and a relatively clear center
● Asymptomatic or mildly itching lesions

87
Q

Dermatophyte infections diangosis

A

● Clinical appearance
● Potassium hydroxide wet mount (KOH prep)→ hyphae will be present

88
Q

Dermatophyte infections treatment

A

● Topical or systemic antifungals
○ “Azoles”
○ Allylamines (terbinafine, naftifine, butenafine)
○ Ciclopirox
○ Tolnaftate
● Nystatin DOES NOT work for dermatophyte infections (however, is effective for Candida infections)
● Recommend NOT using combination antifungal and corticosteroid medications

89
Q

Pediculosis (Lice)

A

● Lice are flattened, wingless insects that infest the hair of the scalp, body,
and pubic region
● Lice attach to the skin and feed on human blood. They lay eggs or nits
on hair shafts

90
Q

Each variety of lice prefers a specific region of the body:

A

○ Head lice - Pediculus humanus var. Capitis
○ Body lice - P. humanus var. Corporis
○ Pubic lice (“crabs”) - Pthirus pubis

91
Q

Pediculosis (Lice) - head lice

A

● Highly contagious
● Transmitted via direct contact
● More frequent in children
● An obligate human parasite, cannot survive on other animals or furniture
● Does not carry any known human diseases
● Lice have a blood meal every 3-6 hours
● Eggs (nits) are firm casts cemented to the hair
shaft, about 1 cm from scalp surface, and
hatch in 8-10 days

92
Q

Pediculosis (Lice)
Skin Findings:

A

● Itching is the primary symptom
● Head lice are 3-4 mm in length, often seen on scalp and hair shafts
○ Commonly seen at back of head or behind the ears
● Nits are fluorescent, may use a Wood’s light exam to screen children

93
Q

Pediculosis (Lice) treatment

A

● OTC Permethrin rinse 1% (Nix)
○ Treatment of choice
○ Shampoo and dry hair. Saturate hair and scalp with medication. Rinse after 10 minutes
● Other topical pediculicides (eg, pyrethrin shampoos, permethrin 5%,
malathion lotion 0.5%)
● Lindane shampoo (UpToDate- not first line d/t safety concerns)
● Repeat treatments in one week, if necessary
● PO Ivermectin- as a single dose, may repeat if needed
● May administer antibiotics if needed for secondary infection

94
Q

Scabies

A

● A parasitic infestation caused by the
mite Sarcoptes scabiei
● Causes intensely itching lesions with erythematous papules and burrows in web spaces, wrists, waistline, and genitals
● Patients may complain of a rash with
severe itching and an inability to stop scratching

95
Q

Crusted scabies

A

● A severe form of scabies
○ The skin contains thousands of
mites and eggs
● May be the source of epidemic scabies
● Often seen in institutionalized or
immunocompromised patients
● Characterized by thick scale, crusts, and
fissures
● May also accompany long-term use of
topical corticosteroids

96
Q

Scabies transmission

A

direct and prolonged
skin-to-skin contact; common among family
members or sexual partners
Transmission through fomites is uncommon for
people with classic scabies, but more likely with
crusted scabies

97
Q

Scabies presentation

A

● Severe itching is generally present
● A linear or curved burrow
○ Slightly elevated vesicle or papule up to
1-2 mm wide
● May also present with scattered inflamed pustules, linear vesicles,
papules etc
● The scabies rash and accompanying pruritus appear 2-6 weeks after
exposure

98
Q

Scabies diagnosis

A

● Often a clinical diagnosis
● Mites, eggs, or feces can be identified via
microscope in a scabies preparation
○ Mineral oil is applied to the burrow, vesicle, or papule to preserve the mite feces. The burrow is then scraped with a #15 blade and placed on a glass slide and viewed under a microscope.
○ Often times it is easier to identify mite body
parts, feces, or eggs, rather than the mites
themselves

99
Q

Scabies
Treatment

A

● Apply permethrin to entire skin surface, neck down. Bathe after 12 hours; repeat
process in one week.
● Wash all bedding and clothing in hot water, or put in hot dryer, at time of
medication application
● May also give single dose of PO ivermectin (Use cautiously in elderly patients)
● Topical steroids may help with pruritus and inflammation that may continue
after eradication of scabies
● Treat all symptomatic people in family and institution at the same time

Derm Exam 2 (5 decks)

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