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Flashcards in SUPERFICIAL BACTERIAL INFECTIONS Deck (133)
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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
Q

Which type of impetigo is relatively frequent throughout the world and associated with outbreaks

A

Pure staphylococcal non-bullous impetigo

26
Q

What age group are commonly affected by impetigo?

A

Pre-school age and young school age children

27
Q

In impetigo, Females are predominantly affected in the adult population (T/F)?

A

False.

Males!

28
Q

Mention 6 factors that predispose a patient to impetigo?

A
Hot and humid weather 
Overcrowding 
Poor hygiene 
Preexisting skin disease esp scabies 
pediculosis
eczema
insect bites
minor trauma
29
Q

Non-Bullous impetigo occurs in all ages and is commoner in childhood (T/F)?

A

False

It’s Bullous

30
Q

the former name for a widespread form of bullous impetigo seen in newborns is what?

A

Pemphigus neonatorum

31
Q

Buccal mucous membranes is never affected in Bullous type of impetigo (T/F)?

A

False

Buccal mucous membranes may be affected.

32
Q

What areas of the body are preferred in infection?

A

Facial affectation

Areas of pre-existing skin dx

33
Q

Non-bullous impetigo is also called what?

A

Impetigo contagiosa of Tilbury Fox

34
Q

the most commonly affected sites in non-bullous impetigo is?

A

The face and the limbs

35
Q

Under what condition is the scalp affected in non-bullous impetigo?

A

in the presence of background Tinea capitis.

36
Q

The mucous membranes are rarely affected in non-bullous type of impetigo (T/F)?

A

True

37
Q

Under what condition would other parts of the body be affected by non-bullous impetigo?

A

in children with atopic dermatitis or scabies.

38
Q

Prolonged course of infection in impetigo can be due to?

A

in the presence of underlying parasitic infections or eczema.
(spontaneous cure in 2-3 weeks)

39
Q

lesions in Bullous impetigo may be followed by temporary hypopigmentation or hyperpigmentation in heavily pigmented skin (T/F)

A

False

It’s in the Non-bullous

40
Q

Severe cases of non-bullous impetigo is usually accompanied by?

A

fever
regional adenitis
other constitutional symptoms.

41
Q

Lesions of impetigo are commonly of the Bullous type in adults (T/F)?

A

False

In children!

42
Q

Impetigo can resolve completely usually without treatment (T/F)

A

True

43
Q

Crusted impetigo sometimes heals with scarring(T/F)?

A

False

Heals without scarring!

44
Q

Impetigo is highly contagious and spread is usually by direct contact (T/F)?

A

True

45
Q

Outline 4 complications of impetigo?

A

Acute glomerulonephritis
scarlet fever
urticaria
erythema multiforme

46
Q

What is the most feared complication of streptococcal impetigo?

A

Acute glomrulonephritis

47
Q

Itemize 6 differential diagnosis of impetigo?

A
Herpes simplex
Eczema 
Atopic dermatitis 
Contact dermatitis 
Bullous pemphigoid 
Candidiasis 
Cutaneous scabies 
Pemphigoid foliaceus 
Thermal burns
48
Q

How would you investigate and treat a patient with impetigo?

A

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
Q

a pyogenic skin infection characterized by ulcers forming under a crusted surface infection is known as

A

ECTHYMA

50
Q

Common sites of ecthyma infection include?

A

Site of an insect bite

Neglected minor trauma

51
Q

Common causative organisms of ecthyma include?

A

Staphylococcus

Streptococcus or occasionally both.

52
Q

Healing usually occurs without scarring in ecthyma (T/F)?

A

False

Healing occurs with scarring!

53
Q

“Removal of the crust reveals an underlying irregular purulent ulcer” describes what?

A

Ecthyma

54
Q

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?

A

ECTHYMA

55
Q

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?

A

ECTHYMA

56
Q

What parts of the body are commonly affected by ecthyma?

A

buttocks
thighs
legs

57
Q

formation of lesions on other parts of the body In ecthyma is potentiated by what?

A

Auto-innoculation

58
Q

Impetigo is associated with auto-innoculation (T/F)?

A

True

59
Q

What group of patients is ecthyma commonly found?

A

IVDU

HIV

60
Q

Ecthyma is an infection of developed countries (T/F)

A

False

Developing countries!

61
Q

Itemize the predisposing factors that lead to ecthyma?

A

Poor hygiene

Malnutrition

62
Q

What clinical signs usually accompanies ecthyma?

A

Regional lymhadenopathy

63
Q

What are the differential diagnoses for ecthyma?

A

Leishmaniasis
Sporotrichosis
insect bites

64
Q

How can diagnosis of ecthyma be made?

A

Clinical

Culture and gram staining of lesions

65
Q

Healing in ecthyma is usually rapid (T/F)

A

False

healing is very slow hence Tx is usually for several wks

66
Q

Itemize the treatment modalities for ecthyma?

A
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
Q

What type of impetigo ruptures leaving an honey colored crusted lesion with a ring of erythema?

A

Non Bullous type

68
Q

The bullae of impetigo(bullous type) may persist for 1 week(T/F)?

A

False

Persists for 2-3 days

69
Q

Circinate lesions may arise due to central healing and peripheral extensions in non Bullous impetigo (T/F)?

A

False

In Bullous impetigo

70
Q

After rupture, thin, flat, brownish crusts are formed in Bullous impetigo (T/F)?

A

True!

71
Q

Bullous impetigo infection is restricted to the facial region (T/F)?

A

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
Q

Gradual irregular peripheral extensions may occur without central healing and several sites may coalesce in Bullous impetigo (T/F)?

A

False

In non Bullous impetigo!

73
Q

The face and the limbs are the most commonly affected sites in impetigo (T/F)?

A

True! Esp Non Bullous type

74
Q

There may be spontaneous cure of lesions in Bullous impetigo in 2-3 weeks (T/F)?

A

False

It’s non Bullous impetigo!

75
Q

parasitic infections or eczema may prolong course of the disease in non Bullous impetigo (T/F)?

A

True!

76
Q

The lesions of impetigo may be followed by temporary hypopigmentation and not hyperpigmentation (T/F)?

A

False

Both hypopigmentation and hyperpigmentation!

77
Q

In Mild cases of impetigo there may be fever,regional adenitis and other constitutional symptoms.

A

False

Severe cases!

78
Q

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)?

A

False

It’s a superficial infection

79
Q

What are the areas commonly affected in bacteria Folliculitis

A

scalp
buttocks
extremities
can occur on any hair-bearing area.

80
Q

Bacteria Folliculitis is always accompanied by pruritus (T/F)?

A

False

Can be asymptomatic

81
Q

systemic symptoms usually are present in bacterial Folliculitis (T/F)?

A

False

Usually absent

82
Q

What is the predominant organism in bacterial Folliculitis?

A

Staph aureus

83
Q

What investigation is done in a case of bacteria Folliculitis?

A

Gram stain and culture of purulent material from the follicular orifice can identify the causative organism of folliculitis.

84
Q

a hair shaft is seen in the center of grouped papules and pustles describes what?

A

Folliculitis!

85
Q

A severe, recurrent form of facial folliculitis due to S. aureus is known as?

A

Sycosis barbae

86
Q

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?

A

Sycosis barbae!

87
Q

Boils are clinically referred to as?

A

Furunculosis

88
Q

Folliculitis is an acute pustular infection of a hair follicle, usually with Staph. aureus (T/F)?

A

False

It’s furunculosis(boils)

89
Q

What age group are especially susceptible to furunculosis?

A

Adolescent boys

90
Q

Outline 6 predisposing factors to furunculosis?

A
DM
steroids
poor hygiene
obesity
hyperhidrosis
exposure of skin to hydrocarbons
heavy oil-based cosmetic ointment
91
Q

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)?

A

False

A Furuncle

92
Q

Necrosis in furunculosis may occur within 2 days or after 2 or 3 weeks.(T/F)?

A

True

93
Q

How would you investigate and suspected case of boil?

A

General examination to Check for underlying skin diseases such as scabies or eczema.
Culture swabs

94
Q

How would you treat a patient with boil?

A

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
Q

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)?

A

False

It’s a deep infection!

96
Q

What group of individuals do carbuncles occur predominantly?

A

They occur predominantly in men and in middle or old age.

97
Q

Carbuncles can sometimes be painless(T/F)

A

False

Always painful

98
Q

Suppuration in carbuncles occurs at multiple follicular orifices after 2 weeks (T/F)?

A

False

After 5-7days!

99
Q

What area of skin is commonly affected by carbuncles?

A

The back!

100
Q

an unusual complication of furunculosis when the central face is involved is what?

A

Cavernous sinus thrombosis

101
Q

A life threatening complication of furunculosis is what? And what favours it?

A

Septicemia

Favoured by malnutrition!

102
Q

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.

A

Carbuncles

103
Q

How would you treat a patient who presents with carbuncles?

A

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
Q

It appears as smooth, dome-shaped and tender. This describes what skin lesion?

A

Carbuncle!

105
Q

an acute toxic illness, usually of infants, characterized by shedding of sheets of skin and infection with phage type I staphylococci (T/F)?

A

False
It’s phage type II
It’s staph scalded skin syndrome

106
Q

Patients with staph scalded skin syndrome are to be managed like burns ptx (T/F)?

A

True!

107
Q

What is the pathogenesis of SSSS?

A

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
Q

In adults, the condition is usually caused by a staphylococcal infection at another site (T/F)?

A

False

In children

109
Q

What toxin mediates staph scalded skin syndrome?

A

Exfoliatin toxin B from staph aureus

110
Q

What antibiotics may be used in the treatment of SSSS?

A

flucloxacillin and erythromycin.

111
Q

an acute infection of the epidermis by Strep. Pyogenes extending into cutaneous lymphatics correctly describes erysipelas (T/F)?

A

False

It’s an infection of the dermis!

112
Q

Erysipelas appears as a poorly-demarcated erythematous, edematous area of tenderness (T/F)?

A

False.

It’s well demarcated!

113
Q

Fever, malaise and flu-like symptoms always precede the skin lesions.

A

False

It may! Not always

114
Q

What is the usual sites of affectation in erysipelas?

A

face or the lower leg

115
Q

What xteristic appearance is seen in erysipelas?

A

peau d’orange appearance

116
Q

What group of individuals are at commonly affected in erysipelas?

A

elderly pxs
debilitated
immunocompromised pxs

117
Q

Erysipelas tends to be recurrent (T/F)?

A

True!

118
Q

Erysipelas subsides with extensive sheeted exfoliation (T/F)?

A

True

119
Q

Progressive lymphedema is common finding in recurrent erysipelas (T/F)?

A

True!

120
Q

Mention 2 differential diagnosis of erysipelas?

A

Angioedema

Allergic Contact dermatitis

121
Q

Outline 3 complications of erysipelas?

A

Lymphoedema
Streptococcal septicaemia
Acute glomerulonephritis

122
Q

How would you treat a patient with erysipelas?

A

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
Q

a hot, sometimes tender area of confluent erythema of the skin due to infection of the deep subcutaneous layer correctly describes what?

A

Cellulitis

124
Q

Cellulitis usually affects which body part?

A

The lower legs

125
Q

erythema in cellulitis is well-demarcated compared to that seen in erysipelas (T/F)?

A

False

Cellulitis is less well-demarcated

126
Q

Cellulitis can affect both the dermis and subcutaneous tissue (T/F)?

A

True

127
Q

Cellulitis may coexist with a deeply-extending erysipelas (T/F)?

A

True

128
Q

Cellulitis often follows______ and the causative organisms include ______?

A

Follows an injury!
Staph
Strep
Other organisms

129
Q

Erysipelas is sometimes considered as a form of cellulitis (T/F)?

A

True

130
Q

State the differences between cellulitis and erysipelas?

A

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
Q

Treatment for cellulitis is the same as for erysipelas (T/F)?

A

True

132
Q

What is the treatment of recurrent cellulitis?

A

low-dose antibiotic prophylaxis, e.g. PENICILLIN V 500mg twice daily should be given
since each episode will cause further lymphatic damage.

133
Q

Outline the principles of management of superficial bacterial infections?

A

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