Skin Infections: Staph and Strep Flashcards
Of the prime skin infections, _____ is more common but ____ has a greater chance of evolving to sepsis from a cutaneous origin.
Of the two, Staph is more common but Strep has a greater chance of evolving to sepsis from a cutaneous origin.
S. aureus is responsible for which cutaneous conditions:
- Impetigo
- Impetiginization
- Folliculitis, Furuncle, Carbuncle
- Staphylococcal Scalded Skin Syndrome
- Toxic Shock Syndrome
morphology, secondary morphology and clinical features of impetigo
• 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.
morphology, secondary morphology and clinical features of 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.
morphology, secondary morphology and clinical features of folliculitis
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.
morphology of furuncle/carbuncle
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.
treatment of furuncles
These lesions are painful. Treatment with a short course or oral cephalosporins is usually warranted.
morphology and etiology of staphylococcal scalded skin syndrome
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.
Toxic shock syndrome (TSS) is an acute ____ disease caused
by a _____ _____
Toxic shock syndrome (TSS) is an acute multisystem disease caused by a S. aureus exotoxin
treatment for toxic shock syndrome
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.
common presentations of streptococcal skin infections.
- Erysipelas
- Cellulitis
- Necrotizing Fasciitis
erysipelas vs classic cellulitis
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.
treatment for erysipelas
10-14 day course of penicillin
morphology of cellulits
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.
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.
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.
areas that cellulitis tend sto occur in children vs adults
In children, cellulitis most often affects the head and neck, whereas in adults it tends to involve the extremities.
treatment for cellulitis
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.
describe mortality rates, morphology, onset appearance and which structures of connective tissue that necrotizing fasciitis affects
• 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%.
impetigo
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.
folliculitis/feruncle
- erythematous rim
- favours occluded areas
furuncle
pediatric skin condition
skull to skin staph
- fever and severe tenderness, leaves behind crusting. perenteral antibiotics.
