2: Skin Infections Flashcards
1
Q
What is erysipelas
A
Superficial form of cellulitis that affects upper dermis and subcutaneous tissue
2
Q
What causes erysipelas
A
Group A streptococcus
3
Q
How will erysipelas present
A
Well demarcated erythematous patch
4
Q
What causes cellulitis
A
- Staphylococcus aureus
2. Group A streptococcus
5
Q
What is cellulitis
A
Infection of lower dermis and SC tissue
6
Q
How will cellulitis present
A
Erythematous patch with indistinct margins
7
Q
What may cause necrotising fasciitis
A
Group A streptococcus and anaerobes
8
Q
What is necrotising fasciitis an infection of
A
Fascia and underlying muscle
9
Q
How will necroitising fasciitis present
A
Rapidly spreading and worsening infection. May cause necrosis - which can present as crepitus, bulla
10
Q
What infection may cause folliculitis
A
S. aureus
P. aeruginosa
11
Q
What is folliculitis
A
Infection of hair follicles
12
Q
What infection causes impetigo
A
- Staphylococcus aurea
- Group A streptococcus
13
Q
What is impetigo
A
Infection of superficial epidermis
14
Q
How will impetigo present
A
Erythematous lesions with yellow crusting
15
Q
What may cause staphylococcal scaled skin syndrome
A
Exotoxin released by staphylococcus aureus
16
Q
What are the two types of HSV
A
HSVI = herpes labialis (Oral)
HSV2 = herpes genitalis
17
Q
What is HSV I
A
Oral Infection
18
Q
What is HSV 2
A
Genital Infection
19
Q
What causes shingles
A
Herpes Zoster Virus
20
Q
What causes herpes zoster opthalmicus
A
VZV
21
Q
How will herpes zoster opthalmicus present
A
- Fever, Headache
- Maculo-papular rash over distribution of ophthalmic. N
- Reduced corneal sensitivity
22
Q
What are low risk HPV virus serotypes
A
6 and 11
23
Q
What do low risk HPV serotypes cause
A
Anogenital warts
24
Q
How will warts present
A
Skin coloured, white scaly patches that present with cauliflower type appearance
25
What are the high risk hPV serotypes
16 and 18
26
What do high-risk serotypes cause
Cervical cancer
27
What are superficial fungal infections
Fungal infections that affect superifical layers of skin, hair or nails
28
What are the three types of superficial fungal infections
1. Dermatophytes
2. Yeasts
3. Moulds
29
What is the main dermatophyte skin infection
Tinea (Ring-Worm)
30
What are two types of yeast superficial skin infections
Candidiasis
| Malassezia
31
What is tinea corpis
Tinea infection of glaborous skin
32
How will tinea corpis lesions present
Clearly defined circular lesions - normally of the trunk and limbs. That have raised and scaly edges. Often itchy
33
What is tinea pedis
Athletes foot
| : Scaling of skin between toes
34
What is tinea capitis
Tinea infection of the scalp
35
How will tinea capitis present
Loss of sections of hair with scaling and flaking in those regions
36
What is tinea unguium
Tinea infection of the nail
37
How will tinea unguium present
Yellow, thickening and crumbling of the nail
38
What is tinea incognito
Incorrect treatment of tinea infection with corticosteroids
39
How will tinea incognito present
Less-demarcated erythematous lesions
40
How will oral candidiasis present
White plaques on mucosa
41
How will candiasis present
Erythema with adjacent satellite lesions in flexures
42
What is pityriasis also known as
Tinea versicolour
43
What causes tinea versicolour
Infection with malassezia furfur
44
How will pityriasis present clinically
Scaly brown patches on trunk that fail to tan
45
How are fungal infections often diagnosed
- Skin scrapings
- Hair or nail clippings
- Skin swabs
46
What cream can be used to treat fungal infections
Terbinafine
47
If a severe fungal infection, what may be used
Oral Itraconazole
48
Why should corticosteroids not be used to manage fungal infections
Leads to tinea incognito
49
What are two examples of skin infestations
1. Scabies
| 2. Cutaneous leishmaniasis
50
How will scabies infections present
- Intense pruritus at night
- Burning sensation
- Elongated erythematous papules (2-10m m)
- Scattered vesicles filled with clear or cloudy fluid
51
How will cutaneous leishmaniasis present
Multiple red macules-papules that occur around sand-fly bite that quickly increase in size and develop central ulceration
52
Define cellulitus
Infection of dermis and underlying upper subcutaneous tissue
53
What are the three bacteria to cause cellulitis
1. Staphylococcus aureus
2. Streptococcus progenies
3. Pasterulla mulocida
54
What is a risk factor for pasterurella mulocida
Secondary to bites from cats/dogs
55
How will cellulitis present clinically
- Poorly- demarcted erythematous lesion
- Commonly over the shins
- May have systemic upset
56
If caused by which bacteria will cellulitis have purulent exudate
S.aureus
57
What is the difference between erysipelas and cellulitis
Erysipelas - Infection of superficial dermis and epidermis
58
How is the diagnosis of cellulitis usually made
Clinically.
59
What is used to classify cellulitis
Eron Classification
60
What is Eron Class I cellulitis
1. No Systemic Upset
| 2. No uncontrolled co-morbidities
61
What is Eron Class 2 cellulitis
1. Systemic upset
| 2. Person is well, but with uncontrolled co-morbidities
62
What is Eron Class 3 Cellulitis
1. Significant systemic upset
| 2. Limb threatening infection secondary to vascular compromise
63
What is Eron Class 4 Cellulitis
Necrotising fasciitis or sepsis
64
What are the 6 criteria for admitting someone to hospital with cellulitis for IV Abx
1. Immunocompromised
2. Less than 1y/o or Frail
3. Eron class III or IV
4. Significant lymphedema
5. Deteriorating condition
6. Peri-orbital or facial
65
What is first-line antibiotic for cellulitis
Flucloxacillin
66
If individuals are allergic to penicillin, what should be given instead of flucloxacillin
Clarithromycin or Clindamycin
67
What are three possible ccomplications of cellulitis
- Necroitisng fasciitis
- Septicaemia
- Abscess
68
What is erysipleas
Superficial infection of superficial dermis and SC tissue
69
What causes Erysipelas
Group A streptococcus
70
Give an example of a Group A streptococcus
Streptococcus Pyogenes
71
How can erysipelas be distinguished from cellulitus
Well-demarcated, raised borders
72
Where will 80% of erysipelas present
Lower limbs
73
How will erysipelas present clinically
Erythematous, Oedematous, Warm lesions of lower limb with lymphagitis
74
What is lymphaginitis
Red streaks will project form the lesion representing inflammation of lymphatic vessels
75
What is the difference between cellulitis and erysipelas in causative agents
Most commonly:
Cellulitis = Staph.A
Erysipelas = Group A Strep.
76
What causes staphylococcal scalded skin syndrome
Epidermolytic toxin released by staphylococcus
77
What typically precede staphylococcal scalded skin syndrome
A mucocutaenous staphylococcal infection such as impetigo
78
In which population does staphylococcal scalded skin syndrome occur
Children
79
What time period does SSS present
Hours-Days
80
How will SSS present clinically
Starts with fever, malaise and erythematous skin - that gives a scalded appearance. Then followed by flaccid bullae. Leisons are extremely common
81
Over which regions is SSS lesions more common
Face
Neck
Axilla
Groin
82
What other symptom is present in SSS
Peril-Oral scaling
83
What sign is positive in SSS
Nikolosky's sign positive
84
How can SSS be distinguished from SJS and TEN
No mucosal involvement
85
Explain pathophysiology of SSS
Staphylococcus releases exotoxin A and B. Which then cleave desmoglein-3 of the epidermis.
86
What is first-line management for SSS
Antibiotics: penicillinase-resistant antibiotics (nafcillin, oxacillin)
87
How long does recovery usually take for SSS
15-19d
