SUPERFICIAL BACTERIAL INFECTIONS Flashcards
1
Q
The resident flora of the skin include what class of organisms?
A
Harmless staphylococci
diphtheroids
micrococci
2
Q
Which group of organisms predominate on the skin surface?
A
Staph. epidermidis
Aerobic diphtheria
3
Q
Which group of organisms predominate deep in hair follicles?
A
Anaerobic diphtheroids
4
Q
Overgrowth of aerobic diphtheroids can result in what skin infections?
A
Trichomycosis axillaris
Pitted keratolysis
Erythrasma
5
Q
Trichomycosis axillaris is otherwise called?
A
Lepothrix
6
Q
What is the causative organism implicated in lepothrix?
A
Corynebacterium tenuis
7
Q
Yellow, beaded appearance of the axillary hair is a characteristic finding in what condition?
A
Trichomycosis axillaris (lepothrix)
8
Q
Lepothrix is seen in majority of adults (T/F)?
A
False
seen in up to one-quarter of adult males if looked for.
9
Q
What are the treatment modalities for lepothrix?
A
Topical antibiotic ointments(clindamycin, erythromycin)
shaving will clear the condition.
10
Q
cribriform pattern of fine punched-out depressions or erosions on the plantar surface of the foot, coupled with an unpleasant smell describes what infection?
A
Pitted kerayolysis
11
Q
What can predispose a patient to pitted keratolysis?
A
Unusually sweaty feet in combination with occlusive shoes
12
Q
How is pitted keratolysis treated?
A
Better hygiene
Fusidic acid or mupirocin ointment is usually effective.
13
Q
What is the causative organism of Erythrasma?
A
Corynebacterium minussitimum
14
Q
A symptom-free, macular-wrinkled, slightly scaly pink, brown or macerated white areas, often found in the armpits or groins, or between the toes describes what infection?
A
Erythrasma
15
Q
What factors can predispose a patient to Erythrasma?
A
Humidity obesity diabetes mellitus hyperhidrosis poor hygiene
16
Q
How does DM affect Erythrasma?
A
Larger area of the trunk may be involved in diabetics.
17
Q
Why will sites of Erythrasma glow under Wood’s light and what colour?
A
Some diphtheroid members produce porphyrins when grown in a suitable medium
PINK
18
Q
How is Erythrasma treated?
A
TOPICAL FUSIDIN three times daily for 7 days OR
ORAL ERYTHROMYCIN 500mg four times daily for 7-10 days.
19
Q
Staph aureus is part of the resident skin flora(T/F)?
A
False
Staph. aureus is not part of the resident skin flora except for a minority who carry it in their nostrils and perineum
20
Q
Mention 6 skin infections caused by staphylococcus or streptococcus
A
Impetigo Ecthyma Furunculosis(Boils) Carbuncle Scalded skin syndrome Erysipelas Cellulitis
21
Q
What are the causes of impetigo?
A
staphylococci
streptococci or both.
22
Q
What are the two types of impetigo?
A
Bullous type
Crusted ulcerated type
23
Q
The Bullous type of impetigo is usually caused by _______ whc produces _______ that causes blisters
A
Staph aureus
Exfoliating toxin A
24
Q
The crusted type of impetigo is usually caused by?
A
Beta hemolytic strains of streptococci
25
Which type of impetigo is relatively frequent throughout the world and associated with outbreaks
Pure staphylococcal non-bullous impetigo
26
What age group are commonly affected by impetigo?
Pre-school age and young school age children
27
In impetigo, Females are predominantly affected in the adult population (T/F)?
False.
| Males!
28
Mention 6 factors that predispose a patient to impetigo?
```
Hot and humid weather
Overcrowding
Poor hygiene
Preexisting skin disease esp scabies
pediculosis
eczema
insect bites
minor trauma
```
29
Non-Bullous impetigo occurs in all ages and is commoner in childhood (T/F)?
False
| It's Bullous
30
the former name for a widespread form of bullous impetigo seen in newborns is what?
Pemphigus neonatorum
31
Buccal mucous membranes is never affected in Bullous type of impetigo (T/F)?
False
| Buccal mucous membranes may be affected.
32
What areas of the body are preferred in infection?
Facial affectation
| Areas of pre-existing skin dx
33
Non-bullous impetigo is also called what?
Impetigo contagiosa of Tilbury Fox
34
the most commonly affected sites in non-bullous impetigo is?
The face and the limbs
35
Under what condition is the scalp affected in non-bullous impetigo?
in the presence of background Tinea capitis.
36
The mucous membranes are rarely affected in non-bullous type of impetigo (T/F)?
True
37
Under what condition would other parts of the body be affected by non-bullous impetigo?
in children with atopic dermatitis or scabies.
38
Prolonged course of infection in impetigo can be due to?
in the presence of underlying parasitic infections or eczema.
(spontaneous cure in 2-3 weeks)
39
lesions in Bullous impetigo may be followed by temporary hypopigmentation or hyperpigmentation in heavily pigmented skin (T/F)
False
| It's in the Non-bullous
40
Severe cases of non-bullous impetigo is usually accompanied by?
fever
regional adenitis
other constitutional symptoms.
41
Lesions of impetigo are commonly of the Bullous type in adults (T/F)?
False
| In children!
42
Impetigo can resolve completely usually without treatment (T/F)
True
43
Crusted impetigo sometimes heals with scarring(T/F)?
False
| Heals without scarring!
44
Impetigo is highly contagious and spread is usually by direct contact (T/F)?
True
45
Outline 4 complications of impetigo?
Acute glomerulonephritis
scarlet fever
urticaria
erythema multiforme
46
What is the most feared complication of streptococcal impetigo?
Acute glomrulonephritis
47
Itemize 6 differential diagnosis of impetigo?
```
Herpes simplex
Eczema
Atopic dermatitis
Contact dermatitis
Bullous pemphigoid
Candidiasis
Cutaneous scabies
Pemphigoid foliaceus
Thermal burns
```
48
How would you investigate and treat a patient with impetigo?
Swabs should be taken for culture but treatment should not be delayed until results are ready.
Localized infection - topical fusidic acid a
MRSA -- Mupirocin(3 times daily)
Extensive infection -- oral antibiotics for 7-10 days
STAPHYLOCOCCUS-- flucloxacillin 500mg four times daily
STREPTOCOCCUS -- penicillin V 500mg four times daily
-Close contacts should be examined closely Children should avoid school for a week after commencement of therapy.
49
a pyogenic skin infection characterized by ulcers forming under a crusted surface infection is known as
ECTHYMA
50
Common sites of ecthyma infection include?
Site of an insect bite
| Neglected minor trauma
51
Common causative organisms of ecthyma include?
Staphylococcus
| Streptococcus or occasionally both.
52
Healing usually occurs without scarring in ecthyma (T/F)?
False
| Healing occurs with scarring!
53
"Removal of the crust reveals an underlying irregular purulent ulcer" describes what?
Ecthyma
54
Small bullae or pustules which have an erythematous base are soon covered by a hard crust of dried exudate which increases in size best describes?
ECTHYMA
55
A patient presents with a chronic, well-demarcated, deeply ulcerative lesions with an exudative crust, base appears indurated with a red Erythrmatous areola. The most likely diagnosis is?
ECTHYMA
56
What parts of the body are commonly affected by ecthyma?
buttocks
thighs
legs
57
formation of lesions on other parts of the body In ecthyma is potentiated by what?
Auto-innoculation
58
Impetigo is associated with auto-innoculation (T/F)?
True
59
What group of patients is ecthyma commonly found?
IVDU
| HIV
60
Ecthyma is an infection of developed countries (T/F)
False
| Developing countries!
61
Itemize the predisposing factors that lead to ecthyma?
Poor hygiene
| Malnutrition
62
What clinical signs usually accompanies ecthyma?
Regional lymhadenopathy
63
What are the differential diagnoses for ecthyma?
Leishmaniasis
Sporotrichosis
insect bites
64
How can diagnosis of ecthyma be made?
Clinical
| Culture and gram staining of lesions
65
Healing in ecthyma is usually rapid (T/F)
False
| healing is very slow hence Tx is usually for several wks
66
Itemize the treatment modalities for ecthyma?
```
MEDICAL
oral antibiotics
IV antibiotics(widespread lesions)
SURGICAL
debridement ffl by d use of antibiotics.
```
PENICILLIN and ERYTHROMYCIN are preferred except in the cases of rxns or resistance to both.
PENICILLIN V and FLUCLOXACILLIN(both 500mg four times daily) for 10-14 days.
67
What type of impetigo ruptures leaving an honey colored crusted lesion with a ring of erythema?
Non Bullous type
68
The bullae of impetigo(bullous type) may persist for 1 week(T/F)?
False
| Persists for 2-3 days
69
Circinate lesions may arise due to central healing and peripheral extensions in non Bullous impetigo (T/F)?
False
| In Bullous impetigo
70
After rupture, thin, flat, brownish crusts are formed in Bullous impetigo (T/F)?
True!
71
Bullous impetigo infection is restricted to the facial region (T/F)?
False
Although there is predilection for facial affectation, other parts of the body can be affected and the lesions can be widely and irregularly distributed
72
Gradual irregular peripheral extensions may occur without central healing and several sites may coalesce in Bullous impetigo (T/F)?
False
| In non Bullous impetigo!
73
The face and the limbs are the most commonly affected sites in impetigo (T/F)?
True! Esp Non Bullous type
74
There may be spontaneous cure of lesions in Bullous impetigo in 2-3 weeks (T/F)?
False
| It's non Bullous impetigo!
75
parasitic infections or eczema may prolong course of the disease in non Bullous impetigo (T/F)?
True!
76
The lesions of impetigo may be followed by temporary hypopigmentation and not hyperpigmentation (T/F)?
False
| Both hypopigmentation and hyperpigmentation!
77
In Mild cases of impetigo there may be fever,regional adenitis and other constitutional symptoms.
False
| Severe cases!
78
Bacterial folliculitis is a deep infection of the hair follicle manifest by discrete 2 to 5 mm papules and pustules on an erythematous base. (T/F)?
False
| It's a superficial infection
79
What are the areas commonly affected in bacteria Folliculitis
scalp
buttocks
extremities
can occur on any hair-bearing area.
80
Bacteria Folliculitis is always accompanied by pruritus (T/F)?
False
| Can be asymptomatic
81
systemic symptoms usually are present in bacterial Folliculitis (T/F)?
False
| Usually absent
82
What is the predominant organism in bacterial Folliculitis?
Staph aureus
83
What investigation is done in a case of bacteria Folliculitis?
Gram stain and culture of purulent material from the follicular orifice can identify the causative organism of folliculitis.
84
a hair shaft is seen in the center of grouped papules and pustles describes what?
Folliculitis!
85
A severe, recurrent form of facial folliculitis due to S. aureus is known as?
Sycosis barbae
86
Appearance of Pustules surrounded by erythema in a 19y/o male(after puberty)after trauma while shaving in the Upper lip, chin and beard region describes what?
Sycosis barbae!
87
Boils are clinically referred to as?
Furunculosis
88
Folliculitis is an acute pustular infection of a hair follicle, usually with Staph. aureus (T/F)?
False
| It's furunculosis(boils)
89
What age group are especially susceptible to furunculosis?
Adolescent boys
90
Outline 6 predisposing factors to furunculosis?
```
DM
steroids
poor hygiene
obesity
hyperhidrosis
exposure of skin to hydrocarbons
heavy oil-based cosmetic ointment
```
91
A red,tender,painful, follicular, inflammatory nodule appears and enlarges and may later discharge pus at its necrotic central core before healing to leave a scar correctly describes a carbuncle (T/F)?
False
| A Furuncle
92
Necrosis in furunculosis may occur within 2 days or after 2 or 3 weeks.(T/F)?
True
93
How would you investigate and suspected case of boil?
General examination to Check for underlying skin diseases such as scabies or eczema.
Culture swabs
94
How would you treat a patient with boil?
Treatment is with topical or oral antibiotics! ERYTHROMYCIN 500mg four times daily for 10-14 days)
occasionally by incision and drainage
ANTISEPTICS such as povidone iodine, chlorhexidine(as soap), and a bath oil can be useful in prophylaxis.
95
superficial infection of a group of adjacent hair follicles with Staph. aureus resulting in a swollen, painful suppurating area discharging pus from several points correctly describes a carbuncle (T/F)?
False
| It's a deep infection!
96
What group of individuals do carbuncles occur predominantly?
They occur predominantly in men and in middle or old age.
97
Carbuncles can sometimes be painless(T/F)
False
| Always painful
98
Suppuration in carbuncles occurs at multiple follicular orifices after 2 weeks (T/F)?
False
| After 5-7days!
99
What area of skin is commonly affected by carbuncles?
The back!
100
an unusual complication of furunculosis when the central face is involved is what?
Cavernous sinus thrombosis
101
A life threatening complication of furunculosis is what? And what favours it?
Septicemia
| Favoured by malnutrition!
102
Necrosis of the intervening skin occurs and sometimes this may occur prior to the follicular discharge with the entire central core being shed leaving a deep ulcer with a purulent floor.
Carbuncles
103
How would you treat a patient who presents with carbuncles?
Treatment should include both topical and systemic antibiotics
ERYTHROMYCIN 500mg four times daily can be given for 10-14 days.
Incision and drainage has been shown to speed up healing.
104
It appears as smooth, dome-shaped and tender. This describes what skin lesion?
Carbuncle!
105
an acute toxic illness, usually of infants, characterized by shedding of sheets of skin and infection with phage type I staphylococci (T/F)?
False
It's phage type II
It's staph scalded skin syndrome
106
Patients with staph scalded skin syndrome are to be managed like burns ptx (T/F)?
True!
107
What is the pathogenesis of SSSS?
The organism releases a toxin, exfoliatin B which causes a split high up in the epidermis and this is followed by loosening of large areas of overlying epidermis, erythema and tenderness
108
In adults, the condition is usually caused by a staphylococcal infection at another site (T/F)?
False
| In children
109
What toxin mediates staph scalded skin syndrome?
Exfoliatin toxin B from staph aureus
110
What antibiotics may be used in the treatment of SSSS?
flucloxacillin and erythromycin.
111
an acute infection of the epidermis by Strep. Pyogenes extending into cutaneous lymphatics correctly describes erysipelas (T/F)?
False
| It's an infection of the dermis!
112
Erysipelas appears as a poorly-demarcated erythematous, edematous area of tenderness (T/F)?
False.
| It's well demarcated!
113
Fever, malaise and flu-like symptoms always precede the skin lesions.
False
| It may! Not always
114
What is the usual sites of affectation in erysipelas?
face or the lower leg
115
What xteristic appearance is seen in erysipelas?
peau d’orange appearance
116
What group of individuals are at commonly affected in erysipelas?
elderly pxs
debilitated
immunocompromised pxs
117
Erysipelas tends to be recurrent (T/F)?
True!
118
Erysipelas subsides with extensive sheeted exfoliation (T/F)?
True
119
Progressive lymphedema is common finding in recurrent erysipelas (T/F)?
True!
120
Mention 2 differential diagnosis of erysipelas?
Angioedema
| Allergic Contact dermatitis
121
Outline 3 complications of erysipelas?
Lymphoedema
Streptococcal septicaemia
Acute glomerulonephritis
122
How would you treat a patient with erysipelas?
Treatment is with PENICILLIN V(or ERYTHROMYCIN) and FLUCLOXACILLIN (500mg four times daily)
INTRAVENOUS ANTIBIOTICS may be given for 3-5 days followed by 1-2 weeks of oral therapy in advanced diseases
Analgesics can also be given
Treat any identifiable underlying disease, e.g. tinea pedis.
123
a hot, sometimes tender area of confluent erythema of the skin due to infection of the deep subcutaneous layer correctly describes what?
Cellulitis
124
Cellulitis usually affects which body part?
The lower legs
125
erythema in cellulitis is well-demarcated compared to that seen in erysipelas (T/F)?
False
| Cellulitis is less well-demarcated
126
Cellulitis can affect both the dermis and subcutaneous tissue (T/F)?
True
127
Cellulitis may coexist with a deeply-extending erysipelas (T/F)?
True
128
Cellulitis often follows______ and the causative organisms include ______?
Follows an injury!
Staph
Strep
Other organisms
129
Erysipelas is sometimes considered as a form of cellulitis (T/F)?
True
130
State the differences between cellulitis and erysipelas?
CELLULITIS
Insidious onset with constitutional signs.
Affects deeper layers of the skin.
Suppuration occurs with abscess formation
ERYSIPELAS
Sudden onset with marked constitutional signs. Affects superficial structures of the skin. Suppuration absent.
131
Treatment for cellulitis is the same as for erysipelas (T/F)?
True
132
What is the treatment of recurrent cellulitis?
low-dose antibiotic prophylaxis, e.g. PENICILLIN V 500mg twice daily should be given
since each episode will cause further lymphatic damage.
133
Outline the principles of management of superficial bacterial infections?
1)Good personal hygiene
2) Management of predisposing factors
LOCAL
▪Attend to traumas,Pressure, Sweating, Bites
▪Treat pre-existing dermatosis
▪Investigate carrier sites: Nose, Axilla, Perineum
SYSTEMIC
▪Treatment of disease like DM
▪Nutritional deficiency
▪Immunodeficiency
LOCAL THERAPY
▪Cleaning with soap-water and weak KMN04 solution
▪Removal of crusts with KMN04 solution ▪Application of antibacterial cream
SYSTEMIC THERAPY
▪Antibiotics
