Skin Infections: Staph and Strep

Question 1

Of the prime skin infections, _____ is more common but ____ has a greater chance of evolving to sepsis from a cutaneous origin.

Answer 1

Of the two, Staph is more common but Strep has a greater chance of evolving to sepsis from a cutaneous origin.

Question 2

S. aureus is responsible for which cutaneous conditions:

Answer 2

• Impetigo
• Impetiginization
• Folliculitis, Furuncle, Carbuncle
• Staphylococcal Scalded Skin Syndrome
• Toxic Shock Syndrome

Question 3

morphology, secondary morphology and clinical features of impetigo

Answer 3

• Morphology: Patch, bulla, erosion
• Secondary Morphology- Crusts, scale
• Clinical features: Staph aureus is the responsible organism for impetigo,
impetiginisation, acute bacterial folliculitis, staph scalded skin syndrome and toxic shock syndrome.Located commonly around thecentral face, the honey coloured crusts, a secondary morphology, mark S. aureus as the etiology. Often this can be treated with topical agents such as fucidic acid or mupirocin ointments.

Question 4

morphology, secondary morphology and clinical features of impetiginization

Answer 4

Morphology: Erosion.

Secondary morphology is often honey crusts or “varnished”

Clinical Features- Impetiginisation is seen anywhere the skin is broken. Here, excoriation of the antecubital fossae in a child with atopic dermatitis shows the honey coloured, sticky crusts common to S aureus. Here the S aureus infection is secondary to the broken skin and hence the term impetiginisation.

Question 5

morphology, secondary morphology and clinical features of folliculitis

Answer 5

morphology: pustule

clincal features: Folliculitis is a very common disorder and is characterized by follicular pustules. Microbial cultures may fail to identify a pathogen, but, of the infectious etiologies, Staphylococcus aureus is the most common.

• *Clinical Features**- Follicular pustules are usually accompanied by an erythematous
  rim. Lesions may be pruritic, tender or painful, especially those on the occipital scalp. Folliculitis favours areas that are occluded and/or have terminal hairs. In addition, shaving exacerbates folliculitis. This often resolves without treatment.

Question 6

morphology of furuncle/carbuncle

Answer 6

Morphology: Nodule

Clinical Features: Abscesses and furuncles (boils) are collections of pus that are
“walled-off” from the surrounding tissues. Whereas an abscess can occur anywhere in or on the body, a furuncle, by definition, involves a hair follicle. A contiguous collection of furuncles is termed a carbuncle. These lesions are painful. Treatment with a short course or oral cephalosporins is usually warranted.

Question 7

treatment of furuncles

Answer 7

These lesions are painful. Treatment with a short course or oral cephalosporins is usually warranted.

Question 9

morphology and etiology of staphylococcal scalded skin syndrome

Answer 9

Morphology: Patch. Scaling or desquamation is a secondary morphology

etiology: Staphylococcal scalded skin syndrome (SSSS) is caused by haematogenous dissemination of the same exfoliative toxins that lead to impetigo. SSSS is primarily a disease of infants and young children, who have decreased renal toxin clearance and/or a lack of toxin-neutralizing antibodies. Clinically, there is often a prodrome of malaise, fever, irritability and severe tenderness of the skin.

Classically, the flexural areas are
the first to exfoliate, leaving behind moist skin and thin, varnish-like
crusting. Patients with severe, generalized forms of SSSS require hospitalization and
parenteral antibiotics.

Question 10

Toxic shock syndrome (TSS) is an acute ____ disease caused
by a _____ _____

Answer 10

Toxic shock syndrome (TSS) is an acute multisystem disease caused by a S. aureus exotoxin

Question 11

treatment for toxic shock syndrome

Answer 11

TSS is characterized by the sudden onset of high fever with myalgias, vomiting, diarrhea, headache and pharyngitis. Rapid progression to hypotensive shock can occur. Patients usually develop diffuse erythema or a scarlatiniform exanthem that starts on the trunk and spreads to the extremities. Severe cases of TSS require intensive monitoring and supportive therapy. Beta- lactamase-resistant antibiotics are used to eradicate the toxin-producing staphylococci.

Question 12

common presentations of streptococcal skin infections.

Answer 12

• Erysipelas
• Cellulitis
• Necrotizing Fasciitis

Question 13

erysipelas vs classic cellulitis

Answer 13

Erysipelas is a superficial variant of cellulitis caused primarily by group A streptococci that affects the dermis with prominent lymphatic involvement; in contrast, classic cellulitis is centred in the deep dermis and subcutaneous tissues.

Question 14

treatment for erysipelas

Answer 14

10-14 day course of penicillin

Question 15

morphology of cellulits

Answer 15

Morphology: Plaque, Bulla
• Clinical Features: Cellulitis is an infection of the deep dermis and subcutaneous
tissue that manifests as areas of erythema, swelling, warmth and tenderness. Cellulitis is most often caused by group A streptococci in adults. In children, cellulitis is sometimes a result of a Staph aureus infection.

Question 16

Cellulitis is often preceded by ____ symptoms such as fever, chills and malaise. The affected area displays all four of the cardinal signs of inflammation: ___ (erythema), ___ (warmth), ___ (pain), and ____ (swelling).

The borders are usually ______ and non- palpable. In severe infections, vesicles, bullae, pustules or necrotic tissue may be present.

Answer 16

Cellulitis is often preceded by systemic symptoms such as fever, chills and malaise. The affected area displays all four of the cardinal signs of inflammation: rubor (erythema), calor (warmth), dolor (pain), and tumour (swelling).

The borders are usually ill-defined and non- palpable. In severe infections, vesicles, bullae, pustules or necrotic tissue may be present.

Question 17

areas that cellulitis tend sto occur in children vs adults

Answer 17

In children, cellulitis most often affects the head and neck, whereas in adults it tends to involve the extremities.

Question 18

treatment for cellulitis

Answer 18

For uncomplicated cases, a 10-day course of an oral antibiotic that covers these organisms such as. dicloxacillin, cephalexin or clindamycin is appropriate. Hospitalization and parenteral antibiotics may be necessary for patients who are seriously ill, have facial involvement or fail to respond to oral therapy.

Question 19

describe mortality rates, morphology, onset appearance and which structures of connective tissue that necrotizing fasciitis affects

Answer 19

• Morphology: Plaque, Bulla. Often, cutaneous findings may be a late stage presentation.

• Clinical Features: Necrotizing fasciitis is characterized by rapidly progressive necrosis
of subcutaneous fat and fascia, which can be life-threatening without prompt recognition, aggressive surgical intervention and immediate antibiotic therapy. Infection begins with an area of exquisite tenderness, erythema, warmth and swelling that does not respond to antibiotics.

The skin appears shiny and tense.
Initially, severe pain may be out of proportion to skin findings. Mortality rates range
from 20% to 40%.

Question 20

Answer 20

impetigo

Question 21

Answer 21

impetiginization

• Morphology: Erosion.
• Secondary morphology is often honey crusts or “varnished”
• Clinical Features- Impetiginisation is seen anywhere the skin is broken. Here,
excoriation of the antecubital fossae in a child with atopic dermatitis shows the honey coloured, sticky crusts common to S aureus. Here the S aureus infection is secondary to the broken skin and hence the term impetiginisation.

Question 22

Answer 22

folliculitis/feruncle

• erythematous rim
• favours occluded areas

Question 23

Answer 23

furuncle

Question 24

pediatric skin condition

Answer 24

skull to skin staph

• fever and severe tenderness, leaves behind crusting. perenteral antibiotics.

Question 25

this person presents with this scarletform rash and diffuse erthemea. she also has fever, myalgia, pharyngitis and a head ache. what are you suspecting and what is it caused by?

Answer 25

suspecting toxic shock syndrome. multisystem diseases cuased by staph exotoxin

Question 26

what is this and what bacteria is causing it

Answer 26

strep-erysipelas

• swelling with lymphatic involvement. more superficial than cellulits. can clear up with 10-14 day course of penicillin

Question 27

Answer 27

cellulitis. affects the dermis of the skin. strep infection is deeper than erysipelas

Question 28

Answer 28

cellulitis

• accompanied by systemic systems like fever chills malaise
• evident signs of inflammation (rubor, callor, pain, tubor)
• illdefined boarders and not palpable.

Question 29

Answer 29

necrotizing fascitiis

characterized by
rapidly progressive
necrosis of
subcutaneous fat and
fascia