Bacterial infections

Question 1

How does impetigo caused by staph and strep differ?

Answer 1

General rule- stpah causes bullae formation, strep causes crusted ulcerated type

Question 2

How does staphylococcal scalded syndrome (SSSS) occur?

Answer 2

Generalized dissemination of exfoliative toxins produced by staph aureus; causes the stratum corneum to slough off

Question 3

What are the potential complications of impetigo?

Answer 3

Acute glomerulonephritis

Question 4

Treatment of impetigo?

Answer 4

Topical antibiotic- fucidic acid, if localised

If more generalised then flucloxacillin 500mg qds

Question 5

DDx to consider in impetigo? (2)

Answer 5

Infected eczema

Herpes simplex

Question 6

Acute pustular infection of a hair follicle usually with staph?

Answer 6

Furunculosis

Question 7

What DDx should be considered in furunculosis if only the groin and axillae are involved?

Answer 7

Hydradenitis suppurativa

Question 8

Treatment of furunculosis? (3)

Answer 8

Incision and drainage
Systemic antibiotics if multiple, patient septic, immunosuppressed
If recurrent- eliminate nasal carriage with topical antibiotics

Question 9

What name is given when a group of adjacent hair follicles become deeply infected with staph? What condition should be tested for in these patients?

Answer 9

Carbuncle

Diabetes

Question 10

SSSS is more likely to occur in which groups of patient?

Answer 10

Children, people with renal failure

Adults have antibody against toxin

Question 11

Well-defined eruption of red skin, preceded by malaisve, shivering and fever

Answer 11

Erysipelas

Question 12

What causes erysipelas?

Answer 12

Streptococal infection, entry usually gained through split in the skin

Question 13

Ill-defined area of redness and swelling; often following an injury and often in areas of dependent oedema

Answer 13

Cellulitis

Question 14

Management of cellulitis?

Answer 14

Flucloxacillin 1g qds

Question 15

Causative agent of cat-scratch disease?

Answer 15

Bartonella

Question 16

Presentation of cat-scratch disease? (3)

Answer 16

Reddish granulomatous papule at site of inoculation; tender regional lymphadenopathy and mild fever; often persists for weeks

Question 17

Unwell feverish child with non-blanching purpuric rash on the trunk and legs- diagnosis, causative agent and management?

Answer 17

Meningitis
Neisseria meningitides/strep pneumoniae
Ceftriaxome + dexamethasone (+ amox if above 60 or immunocomprised)

Question 18

Infective agent in syphilis?

Answer 18

Treponema pallidum

Question 19

Primary stage of syphilis infection?

Answer 19

Painless ulcerated chancre at the site of inoculation (usually genital)

Question 20

Investigation of syphilis?

Answer 20

Dark field microscopy from chancre lesions
Serological tests:
non-treponemal (RPR and VDRL)
treponemal (TPPA)

Question 21

Borrelia burgdorferi is responsible for what condition?

Answer 21

Lyme disease

Question 22

Symptoms of Lyme disease (3)

Answer 22

Slowly expanding erythametous ring (erythema migrans) at site of tick bite
Many annular non-scaly plaques may develop
Fever, malaise, fatigue

Question 23

Potential complications of Lyme disease (4)

Answer 23

Inflammatory arthritis
Pericarditis, myocarditis, endocarditis
Meningitis
Cranial nerve palsies

Question 24

Pattern of fine, punched-out depressions on the heel of someone with smelly feet?

Answer 24

Pitted keratolysis of the heel

Question 25

Investigation of suspected fungal infection? (3)

Answer 25

Scrapings/clippings/pluckings Microscopy Woods lamp

Question 26

Local treatment of fungal infection?

Answer 26

Topical terbinafine, miconazole, clotrimazole

Question 27

When is systemic treatment of fungal infection required?

Answer 27

Tinea of scalp/nails, widespread or chronic infections

Question 28

What is the risk of systemic antifungal treatment?

Answer 28

Hepatotoxicity