Insects, Bacteria, & Viral Flashcards
1
Q
What type of parasite are lice?
A
- ectoparasite
2
Q
What species of lice causes head lice?
A
- Pediculosis capitis
3
Q
What species of lice causes body lice?
A
- Pediculosis corporis
4
Q
What type of lice causes pubic lice?
A
- Pediculosis or Pthirus pubis
5
Q
How is lice spread?
A
- person to person by close contact
- fomites
6
Q
How is lice NOT spread?
A
- jumping
7
Q
What is lice a vector for?
A
- typhus
- trench fever
- relapsing fever
8
Q
Describe the lice ‘workup’
A
- distance of nits away from hair follicle
- cellulose tape
- UV light
9
Q
What are the symptoms of lice?
A
- visible nits
- pruritis
10
Q
What are the treatments for lice?
A
- topical pediculicidal agents
- oral antihelmintics
11
Q
What are the lice treatments effective against?
A
- killing nymphs and mature lice
- not so much against eggs
12
Q
What is the great clinical imitator?
A
- scabies
13
Q
What are the symptoms of scabies?
A
- pruritis
14
Q
What is the pathophysiology of scabies?
A
- female mite burrows into skin
- lays eggs
- move through layers and secrete proteases
- feed on tissue but not blood
15
Q
scybala
A
- scabies feces
16
Q
Why do humans react to scabies infestations?
A
- type IV hypersensitivity reaction to scybala
17
Q
What are the treatments for scabies?
A
- scabicidal
- antipruritic
- antimicrobial if secondary infection
18
Q
What is a characteristic of the brown recluse spider?
A
- dorsal violin shape
19
Q
What is dermonecrotic arachnidisim?
A
- local skin/tissue injury resulting from envenomation
20
Q
What is loxoscelism?
A
- systemic clinical syndrome caused bye envenomation from brown recluse spiders
21
Q
How does a brown recluse spider bite present?
A
- edematous/ischemic bite site
- erythematous halo
22
Q
Why does the margin enlarge peripherally in a brown recluse spider bite?
A
- 2nd to gravitational spread of the venom into the tissues
23
Q
What happens 24-72h after a brown recluse spider bite?
A
- single clear or hemorrhagic vesicle at site
- later forms a dark eschar
24
Q
What is the treatment for a brown recluse spider bite?
A
- wound management
- cool compress to hinder sphingomyelinase D activity
- dapsone
- hyperbaric oxygen
25
What causes latrodectism?
- latrotoxin, a neurotoxin
26
What is characteristic of the black widow spider?
- hourglass on its dorsum
27
What are the 3 phases of a black widow bite presentation?
- exacerbation
- dissipation
- residual
28
What is ominous in the residual phase?
- changes in heartbeat, breathing, or blood pressure
29
What is the treatment for a black widow spider bite?
- pain medication
- muscle relaxants
- antivenom
30
What is cellulitis?
- infection without formation of abscess and without purulent drainage or ulceration
31
When there is intact skin with cellulitis, what causes the majority of cases?
- Strep pyogenes
32
When the skin is not intact with cellulitis, what causes the majority of cases?
- Staph aureus
33
What is a ddx for cellulitis?
- erysipelas
34
How does cellulitis with a systemic infection present?
- violacious
- bullae
- lymphangitis
35
What causes facial cellulitis in children?
- H. influenza B
36
What comorbidities put a patient with cellulitis at risk?
- DM
- chronic edema
- splenectomy
- liver disease
- immunosuppression
- prosthetic implant
- arterial or venous disease
37
How is cellulitis with intact skin treated?
- beta-lactam abx (PCN)
38
How is cellulitis without intact skin treated?
- cefazlin
39
erysipelas
- bacterial infection of upper dermis extending into superficial cutaneous lymphatics
- not deep
40
What is the causative agent of erysipelas?
- Strep pyogenes (St. Anthony's Fire)
41
How does erysipelas present?
- initially small erythematous patch progressing into a fiery-red indurated, tense, & shiny plaque with well demarcated borders
42
What is a ddx for erysipelas?
- SJS/TENS
43
What is the treatment for erysipelas?
- elevation
- saline wet dressings
- PCN
44
What are common complications of erysipelas?
- abscess
- gangrene
- thrombophlebitis
45
What are the two types of impetigo?
- nonbullous
| - bullous
46
What causes impetigo?
- S. aureus
47
How does impetigo present?
- folliculitis
| - superficial, yellow, crust
48
What are the treatments for nonbullous impetigo?
- topical mupirocin
| - antihistamines
49
What are the treatments for bullous impetigo?
- systemic antibiotics
| - antihistamines
50
What are the classic exanthems?
- 1st-6th disease
51
What are the other names for 1st disease?
- measles
- rubeola
- morbilli
52
What are the other names for 2nd disease?
- scarlet fever
53
What are the other names for 3rd disease?
- rubella (German measles)
54
What are the other names for 4th disease?
- Duke's disease
| - staph scalded skin
55
What are the other names for 5th disease?
- erythema infectiosum
56
What are the other names for 5th disease?
- erythema infectiosum
57
What are the other names for 6th disease?
- roseola infantum
| - exanthem subitum
58
How does measles present?
- incubation period
- prodrome
- rash
59
What is the incubation period for measles?
- 10-12d
60
What is characteristic of the prodrome phase prior to measles?
- febrile
- cough
- coryza
- conjunctivitis
- Koplik spots
61
coryza
- heavy rhinorhea
62
Koplik spots
- tiny white dots on mucous membranes inthantum
63
What is the time frame for the rash of measles?
- 2-4d after prodrome, 14d after exposure
64
Describe the measles rash
- discrete maculopapular that becomes confluent
| - begins on face and head goes to trunk and extremities
65
How long does the measles rash last?
- 5-6d
66
How does the measles rash disappear?
- fades in order of appearance
67
How does scarlet fever develop?
- within 24-48 hours of onset of symptoms in untreated group A strep infected children
68
What is characteristic of scarlet fever presentation?
- scarletina rash
- peeling of the skin
- 'hot potato'
69
What does hot potato mean in relation to scarlet fever?
- beefy-red uvula preventing clear speech
70
How is scarlet fever diagnosed?
- throat culture
| - rapid antigen test
71
What is the acute presentation of untreated strep pharyngitis?
- scarlet fever
72
What is the presentation 3-6mo after untreated strep pharyngitis?
- rheumatic fever
73
What is the next step after a negative rapid strep test?
- throat culture
74
What is a ddx for failed or relapsed within 1 week strep pharyngitis?
- mononucleosis
75
What is rubella generally?
- benign communicable exanthematous disease
76
What is the causative agent of rubella?
- rubella virus
77
What is the epidemiology of rubella in young children?
- mild constitutional symptoms
- rash
- suboccipital adenopathy
78
What is the epidemiology of rubella in older children, adolescents, and adults?
- complicated by arthralgia, arthritis, and thrombocytopenia purpura
79
What is a rare complication with rubella?
- encephalitis
80
What is a concern for pregnant women with rubella?
- teratogenic effects when contracted early in the pregnancy
81
What is the diagnosis for a fetus born to a mother who contracted rubella while pregnant?
- congenital rubella syndrome
82
How does rubella present?
- 2-3 after incubation
- pharyngitis
- Forchheimer sign
- tender lymphadonopathy
83
How does postnatal rubella present?
- discrete rose-pink maculopapular rash
- pruritic
- febrile
- enlarged lymph nodes
- forchheimer sign
84
What are serious complications from congenital rubella syndrome?
- deaf
- blind
- cardiac issues
85
What does a congenital rubella syndrome kid look like?
- blueberry baby
86
What is erythema infectiosum?
- benign, childhood condition
87
What causes erythema infectiosum?
- human parvovirus (HPV) B19
88
How is erythema infectiosum transmitted?
- respiratory secretions
- fomites
- parenterally from mother to fetus
89
Describe phase 1 of erythema infectiosum
- bright red, raised, slapped-cheek rash
| - spares the nasolabial folds
90
What is associated with erythema infectiosum?
- arthropathy
| - anemia
91
Describe phase 1 of erythema infectiosum
- bright red, raised, slapped-cheek rash
| - spares the nasolabial folds
92
Describe phase 2 of erythema infectiosum
- maculopapular rash fades into classic lace-like reticular pattern
93
Describe phase 3 of erythema infectiosum
- recurrence of lacy rash worse with heat or exercise
94
What is fetal hydops?
- fetal transmission of erythema infectiosum
95
How does erythema infectiosum present?
- pruritic
- exanthem only
- rash in children
96
What is exanthem subitum?
- roseola
97
What causes roseola?
- human herpesvirus 6 (HHV-6)
98
What is the classic presentation of roseola?
- 9-12mo
- acute
- high febrile
- seizure
- Nagayama spots
- 72 hr later, defervescence
99
What patient population gets recurrence of roseola?
- immunocompromised
100
What are Nagayama spots?
- small, white dots on soft palate
101
What is the causative agent of varicella?
- varicella-zoster virus
102
How is varicella transmitted?
- respiratory droplets
103
Where are high viral titers found in a patient with varicella?
- vesicles
104
What does varicella infect?
- conjunctiva
| - mucosae of upper respiratory tract
105
What is the 2nd viremia characterized by with varicella?
- diffuse viral invasion of capillary endothelial cells and the epidermis
106
What happens to varicella after the initial infection?
- VZV spreads to local sensory nerves
| - remains latent in the dorsal ganglion cells of sensory n.
107
What is reactivation of VZV?
- shingles
108
How does varicella present?
- intensely pruritic with vesicles
| - head to neck to trunk to extremities
109
When can children return to school?
- when the most distal lesion has scabbed
110
What are 'dew drops on a rose petal'?
- description of varicella vesicles
| - reddish irregular papule with clear vesicle on top
111
What are the complications of varicella?
- secondary bacterial infection
- disseminated primary varicella infection
- CNS
- hemorrhagic
112
When there is a secondary bacterial infection of varicella, what is often suspected?
- strep pyogenes
113
What is the patient population with the complication from varicella of disseminated primary varicella infection?
- immunocompromised
| - adult
114
What are the CNS complications from varicella?
- Reye's
- Guillain-Barre
- acute cerebellar ataxia
- encephalitis
115
What is in utero VZV infection?
- primary maternal varicella during pregnancy
| - produces latency of VZV in DRG of fetus
116
What is reactivation of VZV associated with?
- aging
- immunosuppression
- intrauterine exposure
- varicella younger than 18mo
117
What is an after effect of healed, reactivated VZV?
- postherpetic neuralgia (phantom pains)
118
How is varicella diagnosed?
- Tzanck smear
- vesicular fluid culture
- serological testing for IgG
- chest XR
- histological exam
119
What is the treatment for varicella?
- clip nails
- antihistamines
- abx for 2ndary infection
120
How is varicella prevented?
- vaccine
121
What does HPV (human papilloma virus) cause?
- epithelial tumors of skin and mucous membranes
122
Who are at risk of getting HPV?
- people with multiple sexual partners
| - people with HPV
123
What are the three clinical categories of HPV?
- anogenital or mucosal
- nongenital cutaneous
- epidermodysplasia verruciformis (EV)
124
What is not a prevention for HPV spread?
- condoms
125
What does nongenital cutaneous HPV cause?
- verruca vulgaris
126
Where do verruca vulgaris present?
- keratinized skin
127
How are verruca vulgaris transmitted?
- autoinoculation yields kissing warts
128
What is verruca vulgaris?
- common cutaneous warts
129
What are verruca plana?
- flat warts
130
How is epidermodysplasia verruciformis genetically transfered?
- autosomal recessive familial trait
131
What are the low risk HPV types?
- 6 & 11
132
What is condylomata acuminata?
- genital warts
| - benign proliferations of the anogenital skin and mucosa
133
What are the high risk HPV types?
- 16 & 18
134
What do HPV 16 & 18 lead to?
- high-grade intraepithleial lesions that may progress to carcinomas
135
What is the immune response to HPV?
- weak cell mediated
| - humoral does not occur until viral particles released from superficial cells
136
How do HPV lesions resolve?
- spontaneously
137
What are the HPV malignancy factors?
- oral contraceptives
- chewing Indian betel quid
- UV and XR irradiation
138
What is laryngeal papillomatosis?
- warts on the larynx
139
Which HPV virus is implicated in laryngeal papillomatosis?
- 6, 11, & 16
140
What symptoms are involved with laryngeal papillomatosis?
- hoarseness
- voice change
- croupy
- cough
- stridor
141
How is laryngeal papillomatosis diagnosed?
- direct laryngoscopy
142
How is laryngeal papillomatosis transmitted?
- vaginal delivery
143
How is HPV diagnosed?
- clinically
- visually with acetic acid
- PAP smear
144
What is the treatment for HPV?
- no single cure
| - ablate the lesions
145
How does molluscum contagiosum present?
- multiple, rounded, dome-shaped, pink waxy papules
- 2-5mm
- umbilicated
- with a caseous plug
146
Where does molluscum contagiosum present?
- along a line of minor skin trauma
147
What are the three different patient populations who get molluscum contagiosum?
- children
- immunocompetent adults
- immunocopromiesd children and adults
148
How do children get mollusucm contagiosum?
- direct skin-to-skin contact
| - fomites
149
How doe immunocompetent adults get molluscum contagiosum?
- STD
| - lesions limited to perineum, genitalia, lower abdomen, or buttocks
150
Describe the molluscum contagiosum lesions in immunocompromised patients
- widespread
- persistant
- atypical
151
Where is the distribution for molluscum contagiosum in children v. adults?
- children: face, trunk, and extremities; not pathognomic of abuse in groin, perineal, or genital
- adults: groin and genitalia
152
Where is molluscum contagiosum not found and why?
- palms, soles, oral mucosa, conjunctiva
| - thick skin
153
How does molluscum contagiosum resolve?
- spontaneously
154
What are the treatment options for molluscum contagiosum?
- benign neglect
- direct trauma to lesions
- antiviral therapy
- immune response stimulation
155
What HSV is associated with orofacial disease?
- HSV 1
156
What HSV is associated with genital disease?
- HSV 2
157
What is a good preventative measure for transmission of HSV?
- condoms
158
What makes HSV biologically unique?
- neurovirulence
- latency
- reactivation
159
How is HSV transmitted?
- close personal contact
160
What is acute herpetic gingivostomatisis?
- primary HSV 1 infection in children
161
What are the clinical features of acute herpetic gingivostomatisis?
- abrupt onset
- high T
- anorexia
- gingivitis
- vesicular lesions
- perioral skin involvement
162
How are infections differentiated between HSV 1 and HSV 2?
- culture
163
What is the most common manifestation of recurrent HSV1?
- acute herpetic labialis (lip sore)
164
What are the characteristics of the primary v. recurrent HSV 2 genital infection?
- primary: more severe and prolonged
| - recurrent: less severe and shorter
165
How do HSV 1 and 2 'protect' against each other?
- HSV1 protects against HSV2 severity
| - orolabial HSV1 protects against genital HSV1 but not 2
166
How does genital herpes present in women?
- vesicles in moist areas that rupture leaving tender ulcers
- cervix involvement in 70-90%
- dysuria
167
How does genital herpes present in men?
- vesicles in dry areas that progress to pustules then encrust
- urethritis
- dysuria
- proctitis
168
How is HSV diagnosed?
- culture
- immunoflorescent staining
- punch biopsy
169
What are complications from HSV?
- bacterial and fungal superinfections
- candidal vaginitis
- ocular infections
- skin
- CNS complications
- pregnancy needs c-section
170
What is the treatment for HSV?
- based on specific antiviral treatment
| - symptomatic
