Dermatology - Bacterial Skin Infections Flashcards
Pustules
Furuncls
Erosions with honey colored crusts
A. Gram (+) cocci
B. Gram (-) cocci
A. Gram (+) cocci
Indicators of Staphylococcus aureus infection
Bullae
Widespread erythema
Desquamation (scaling and crusting)
Vegetating pyodeermas
Confluence of pustules
Pyodermas
Indicated by a purulent purpura
Caused by S. Aureus or immunocompromised ptx infected with S. Epidermidis
endocarditis
Painful, erythematous nodule with pale center located ion the fingertips
Osler node
3 signs of endocaditis
Purulent purpura
Osler node
Janeway lesion
Nontender, angular hemorrhagic lesion of the palms and soles
Janeway lesion
Janeway lesion is likely to be due to
Septic embolic
Normal habitation of S. Aureus
Anterior nares (20-40%)
Hands
Perineum
Spread of S. Aureus in the hospital is frequently traced to
Hands of a healthcare worker
Is essential in limiting nosocomial complication of S. Aureus
Proper handwashing
PF to MRSA
Age (older thna 65)
Exposure to others with MRSA
Prior antibiotic therapy
Recent hospitalization or chronic illness
Tx MRSA
IV vancomycin
Linezolid
Ptx with no RF for MRSA
Tx of S. Aureus infection
Clindamycin
Trimethoprim - sulfamethoxazole (alone or w/ rifampin)
Minocycline
Oral linezolid
Mamaso
Impetigo
Tagalog word for Impetigo
Mamaso
T/F
Impetigo
Common contagious superficial skin infection
T
Impetigo
Does it scar?
No
RF for impetigo
Any spontaneous or induced lesions may become secondarily infected
Causative agents
Staphylococci -
Streptococci
Combination of both
What is the specie isolated from majority of lesions in both bullous and nonbullous impetigo
A. Staphylococci
B. Streptococci
A. Staphylococci
Now known as the primary pathogen to both bullous and nonbullous impetigo
S. Aureus
Produces an epidermolytic toxin that lyses the desmosomes which chemically split the epidermis
S. Aureus
S. Aureus
What causes the blister formation
Epidemolytic toxin
Start as oozing erosion, or transient thin-roofed vesicle which inc. in size rapidly that develop honey colored crust
Thought to be primarily streptococcal dse (now staphylococcal)
Non-bullous impetigo
Age demographic common to have bullous impetigo
Infants
Staphyloccocal disease
Lesions are vesicles (fluid filled <5 mm) and bullae (>5mm) on bland, non-inflamed skin
Dried, collapsed roofs of vesicles cover very superficial erosions
Bullous impetigo
Consitutional sx
Bullous impetigo
Initially absent
Later, weakness, fever, subnormal tempetrature
Diarrhea with green stools
Bullous impetigo complication
Bacteremia
Pneumonia
Meningitis
Develop rapidly with fatal termination
Tx and management impetigo
Lesions sprinkled with penicillin -dangerous because hypersensitivity rxn may develop
Moist, weeping lesions - cream
Dry - ointment
Keep injured area clean
1. Gentle washing
2. Antibacterial soap
3. Soaks or compresses (PNSS)
Gentle debridement with fingers or gauze after soak
Topical antibiotic - Mupirocin, Gentamicin
widespread and resistant - cloxacillin
Tx widespread and resistant cases impetigo
Cloxacillin
Impetigo of Bockhart
Superficial pustular folliculitis
Superficial pustular folliculitis
Impetigo of Bockhart
Superficial folliculitis with thin-walled pustules at the follicle orifices
Superficial pustular folliculitis
Favorite locations of Superficial pustular folliculitis
Extremities
Scalp
Face (periorally)
Fragile, yellow-white, domes pustules develops in crops and heal in a few days
Superficial pustular folliculitis
Most frequent cause of Superficial pustular folliculitis
S. Aureus
Superficial pustular folliculitis secondarily arises in
Scratches, insect bites, other skin injuries
Sycosis barbae
Sycosis vulgaris
Formerly known as barber’s itch
Sycosis barbae
A perifollicular, chronic, pustular staphylococcal infection of the bearded region
Sycosis vulgaris
Inflammatory papules and pustules and tendency to recurrence
Begins with erythema and burning or itching usually on the upper lip near the nose
In a 1-2 days, one or more pinhead-sozed pustules pierced by hairs develop
Sycosis vulgaris
There pustules rupture after shaving and leave a crop of erythematous spot, which is later the site of fresh crop of pustules, in this manner the infection persists and gradually spreads
Sycosis vulgaris
With severe cases of sycosis barbae, what other disease is usually present
Marginal blepharitis with conjunctivitis
Inflammation of eyelids in which they become red, irritated, and itchy, and dandruff-like scales form on the eyelashes
Blepharitis
Diffrential diagnosis for sycosis vulgaris
Tinea barbae
Acne vulgaris
Pseudofolliculitis barbae
Hepetic sycosis
Common location for sycosis
Not usually affected by tinea barbae
Sycosis barbae
Usual area affected by tinea barbae
Submaxillary region, or on the chin (beard area)
Spores and hyphae are found in the hairs
Tinea barbae
Manifests topid papules at the sites of ingrowing beard hairs in black men
Pseudofolliculitis barbae
Differential diagnosis for sycosis barbae caused by herpes simplex type 1
Herpetic sycosis
Herpetic sycosis caused by
HSV-1
Vesicles that lasts for a few days in the beard area
Herpetic sycosis
Tx sycosis vulgaris
Oral and topical antibiotics
Corticosteroids
Antifungal agents
Diagnosis sycosis barbae
Request gram stain
Inflammation of hair follicles
Caused by bacterial infection, chemical irritation, physical injury
Folliculitis
Does folliculitis heal without scarring?
Depends on its depth of infection
Painless or tender pustule that heals without scarring
Folliculitis
Painless or tender pustule that heals without scarring
Dirty yellow or gray erythema
Folliculitis
Pustule is confined to the ostium of the hair follicle
Folliculitis
Involves the sweat ducts
Folliculitis
Milliaria
Folliculitis
Involves the sebaceous glands wherin secretions come off the hair follicles
Millia
The pustule is not associated with hair follicle
Milliaria pustulosa
Folliculitis infection with Staphylococcus in the face
Folliculitis barbae
Folliculitis in the scalp of legs
Follicular impetigo
It causes red sores that can break open, ooze fluid, and develop a yellow-brown crust. These sores can occur anywhere on the body.
Impetigo
Impetigo affects this age group very often
Impetigo
Folliculitis in the trunk caused by pseudomonas aeroginosa
Hot tub folliculitis
Hot tub folliculits is caused by
Pseudomans aeroginosa
Back folliculitis
reaches young children and usually follows the miliaria, with inflammatory nodules or superficial pustules that eventually drain pus.
Periporitis suppurativa
in this case the infectious process leads to atrophy of the hair, leaving bald patches that extend due to peripheral progression of the disease.
Folliculitis decalvans
Gram + cocci in clusters
Staphylococcus
Gram + cocci in pairs/chains
Streptococcus
Folliculitis considerd to be a sexually transmitted disase
Miniepidemics of folliculitis nd
Furunculosis of genital and gluteal areas
Tx of folliculitis
Heal with drainage (deep lesions of folliculitis) and topical tx
Removal of exciting agents 3 times a day with antibacterial soaps
Topical antibiotics
Systemic antibiotics
Topical antibiotics used for folliculitis
Mupirocin (Bactroban)
Retapamulin - non responsive to mupirocin
Fusidic acid
Folliculitis
If drainage fail/ soft tissue infections
Tx
Systemic antibiotic
Systemic antibiotic for Folliculitis
1st generation cephalosporin ( IV cephazolin, cephalothin; Oral: Cephalexin, cephradine, cefadroxil)
Penicillinase resistant penicillin
(Cloxacillin, dicloxacillin)
Aqueous solution of aluminium triacetate. It jas astringent and antibacterial properties.
Burrow’s solution
When folliculitis is acute and wet tx
Soak with burrow’s solution diluted 1:20
Chronic folliculitis esp. for buttocks
Anhydrous formulation of aluminium chloride (can be used once a night)
Pigsa
Furuncle
Acute, deep-seated, erythematous, hot, very tender inflammatory nodule
Furuncle
Evolves from staphylococcal folliculitis
Deeper lesion
Furuncle
Boil
Furuncle
Acute, round, tender, circumscribed, perifollicular staphycoccal abscess that generally ends in central suppuration
Furuncle, boil
2 or more confluent furuncles, with separate heads
Carbuncle
PR for furuncle
Chronic staphyloccocal carrier states in nares or perineum
Intergrity of the skin surface - irritation, pressure, friction, hyperhidrosis, dermatitis, dermatophytosis (tinea), shaving
Systemic disorders- alcholism, manutrition, blood dyscrasias, disorder neutrophil function, iatrogenic or other immunosuppression, AIDS, diabetes
Obesity
Bactericidal defects
Scabies, pediculosis, abrasions
hard nodule -> fluctuant abscess with central necrotic plug -> rupture -> ulceration -> scarring
Furuncle
Bright red, indurated round plaque
Isolated single lesions or few multiple lesions (Scattered discrete)
Occurs only where there are hair follicles and in areas subject to friction and sweating
Furuncles
Areas commonly affected by furuncles
Nose Neck Face Axilla Buttocks
Lab examination for a suspected furuncle
Incision and drainage of abscess (gram stain, culture, antibiotic sensitivity)
Blood culture - fever, constitutional symptoms
Tx of simple furunculosis
Local application of heat (15-20 mins)
Incision and drainage (if antibiotics failed)
Tx furunculosis with surrounding cellulitis or fever
Systemic antibiotics for 1-2 weeks
Penicillinase- resistant penicillin (cloxacillin, dicloxacillin) or
1st generation cephalosporin orally dose of 1-2 g/day according to severity of case
Type of furunculosis difficult to tx
Recurrent furunculosis
May be related to persistent staphylococcus in the nares, perineum, and body folds
Type of furunculosis
Recurrent furunculosis
Tx for Recurrent furunculosis
Frequent bathing, germicidal soap
Antibacterial ointments
(Bactroban - anterior nares daily or 5 days, bleach baths prevent recurrence)
Oral antibiotic until all lesions have resolved, and as a OD prophylactic dose for many months
Bakokang / piso piso
Ecthyma
Uncerative impetigo
Ecthyma
Ulcerative staphylococcal or streptococcal pyoderma, (usually) of the shins and dorsal feet
Ecthyma
Lesion of neglect
Ecthyma
Ecthyma develops in
Minor trauma
Insect bites
Excoriations
Etiology ecthyma
Group A beta-hemolytic streptococci (GAHBS)
Staphylococci
Both
Disease begins with a vesicle, or vesicopustule which enlarges in a few days becomes thickly crusted.
When crust is removed, there is a suprficial saucer-shaped ulcer with a raw base and elevated edges
Ecthyma
PF for ecthyma
Uncleanliness
Malnutrition
Trauma
Round, oval 0.5 to 0.3 cm Indurated ulcer Dirty yellowish-gray crust Pruritus and tenderness Located on the lower extremities Last for weeks
Ecthyma
Tx ecthyma
Cleansing with soap, water, followed by application of mupirocin, retapamulin, bacitracin ointment twice a day
Systemic tx is usually indicated Cloxacillin Dicloxacillin Erythromycin ( for sensitive S. Aureus) Clindamycin (MRSA)
Ecthyma MRSA tx
Clindamycin
Ecthyma same supportive management as
Impetigo
Gentle washing, antibacterial soap
Soaks or compresses
Gentle debridement with fingers or gauze after soak
Moist lesions - use cream
Dry lesions - ointment
Acute spreading infection of the dermis and subcutaneous tissue
Cellulitis
Cellulitis
Caused most frequently by
S. Pyogenes or S. Aureus
Most common portal of entry of cellulitis
Tinea pedis
Cellulitis accompanying sx and signs
Mild local erythema and tenderness, malaise, chilly sensations,sudden chill and fever may be present at onset
Erythematous, hot edematous Very tender Vary in size nad shape Borders are usually sharply defined, irregular, slightly elevated Associated with lymphangitis
Cellulitis
Can form on the plaques and primary lesions of cellulitis
Vesicles, bullae, erosions, abscesses, hemorrhage, necrosis
Kolebra
Erisypelas
Also known as St. Anthony;s fire and ignis sacer
Erysipelas
Acute, superficial inflammatory form of cellulitis
Involves superficial dermal lymphatics (streaking prominent)
Painful
Margins more clearly demarcated than normal skin
More superficial
Erysipelas
What makes erysipelas differ from other types of cellulitis
Involves superficial dermal lymphatics (streaking prominent)
Margins more clearly demarcated than normal skin
More superficial
Cause of erysipelas
Acute beta hemolytic group A streptococcal infection
Group B in newborn, abdominal or perineal erysipelas in postpartum women
Characterized by local redness, heat, swelling, highly characteristic raised indurated border
Erysipelas
Erysipelas often preceded by prodromal sx of
Malaise for several hours
Severe constitutional rxn with chills, high fever, headache, vomiting, joint pains
Early stages Erysipelas, affected skin is
Scarlet
Hot to touch
Branny and swollen
Distinctive feature of the inflammation is the advancing edge of the patch
This is raised and sharply demarcated, feels like a wall to the palpating finger
Often painful
Erysipelas
Sites of predilection
Erysipelas
Lower legs -edema and bullous lesions, spreads centrally
Face - cheek, near the nose, in front of the lobe of the ear and spreads upward toward the scalp, hairline (usually) acts as a barrier against further extension
Ears
Umbilical stump
Areas of pre-existin lymphedema
PR
Erysipelas
Operative wounds fissures - nares, auditory meatus, under the lobes of the ears, anus, penus, between an under toes (little toe usually) Abrasions or scratches Venous insufficiency Obesity Lymphedema Chronic leg ulcers
Tx Erysipelas
Systemic penicillin - rapidly effective (24-48 hours)
Vigorous tx with antibiotics - continued 10 days
Locally, ice bags, cold compresses may be used
Leg involvement - likely require hospitalization with IV antibiotics
H. Influenza cellulitis mainly in (age)
Young children <3 years old
Most common sites of H. Influenza cellulitis
Most common : cheek, periorbital area, head and neck
Ecthyma gangrenosum caused by
P. Aeuroginosa
Most common site of Ecthyma gangrenosum
Extremity
Ecthyma that rapidly becomes necrotic, leads to ulcer
Ecthyma gangrenosum
Rapidly progressive
Extensive necrosis of subq tissue and overlying skin
Infectious gangrene
Etiology infectious gangrene
Group A beta-hemolytic Streptococcus pyogenes
S. Aureus
Etiology of infectious gangrene
Adults with underlying disease
Clostridium septicum P. Aeruginosa E. Coli Acinetobacter Pasteurella multocida H. Influenza enterobacter Proteus mirabilis
Etiology of infectious gangrene
Children
H. Influenza
Group A streptococci
S. Aureus
Transmission infectious gangrene
Break in the skin (puncture, abrasion, laceration, surgical site)
Underlying dermatosis (tinea pedis, stasis dermatitis/ ulcer)
Nasal fissures
RF infectious gangrene
Diabetes mellitus Hematologic malignancies IV drug use Immunocompromise Chronic lymphedema
Tx infectious gangrene
Oral antibiotics
Wound care - debridement
