bacterial skin infections_course viii.ppt
TRANSCRIPT
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
1/37
Bacterial SkinBacterial SkinInfectionsInfections
ProfessorSudheer Kher
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
2/37
Learning Objectives
Enumerate the microbes causing skininfections.
Describe thecharacteristic clinical manifestationsmethods of laboratory diagnosis
principles of managementmethods of prevention of each of theinfections listed.
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
3/37
Bacterial
Infection of SkinThe SkinDefinition
Skin is largest organ of body. Maintainshomeostasis, protects underlying tissues andorgans, protects body from mechanical injury,damaging substances, and ultraviolet rays ofsun.
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
4/37
Recurrent skin
infectionsRecurrent skin infections should raisesuspicion of coloni ation
Staphylococcal nasal carriageResistant strains of bacteria !eg, methicillin"resistant Staphylococcus aureus #MRS$%&,'ancer
(oorly controlled diabetes)ther reasons for immunocompromise !eg, *+ ,hepatitis, advanced age, congenital susceptibility&.
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
5/37
Pyoderma(yoderma is a group name for pyococcal dermatoses-hich are generally purulent. +n tropical countries,pyoderma is a common problem, particularly in thesummer and the monsoon.
The t-o important pyogenic organisms are theStaphylococcus aureus and the Streptococcus pyogenes.
ollicular infections are mainly due to staphylococci/-hile erysipelas and cellulitis are caused by streptococci.
0esides these, other organisms -hich occasionally comeacross in pyodermas are (roteus, (seudomonas and'oliform bacilli.
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
6/37
Skin Infections
Infection Site Causal Organism
Boil Hair follicle Staphylococcus aureus
Carbuncle Multiple Hair follicles Staphylococcus aureus
Stye Hair follicle of eye lash Staphylococcus aureus
Sycosis barbae Shaving area Staphylococcus aureus
Pemphigus neonatorum Infants skin Staphylococcus aureus
To ic epi!ermalnecrolysis
Infants skin Staphylococcus aureus
Pemphigus neonatorum Infants skin Staphylococcus aureusTo ic epi!ermalnecrolysis
Infants skin Staphylococcus aureus
"rysipelas #ace$ sometimes limbs Streptococcus pyogenes
%cne vulgaris #ace & Back Propionibacterium acnes
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
7/37
S. aureus produces
skin infection+. Direct infection of skin and adjacent tissuesa. +mpetigob. Ecthyma
c. olliculitisd. urunculosise. 'arbunclef. Sycosis barbae
++. 'utaneous disease due to effect of bacterialto1ina. Staphylococcal scalded skin syndrome
b. To1ic shock syndrome
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
8/37
!emolyticstreptococcus produces
skin infection+. Direct infection of skin or subcutaneousa. +mpetigo !non bullous&b. Ecthymac. Erysipelasd. 'ellulitise. 2ecroti ing fascitis
++. Secondary infectionEc ema infection
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
9/37
"olliculitisFolliculitis is a bacterial infection of hairfollicles. #olliculitis is usually cause! byStaphylococcus aureus but occasionallyPseu!omonas aeruginosa 'hot(tubfolliculitis) or other organisms* Hot(tub
folliculitis occurs because of ina!e+uatetreatment of ,ater ,ith chlorine orbromine*
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
10/37
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
11/37
#olliculitis manifests as superficial pustules orinflammatory no!ules surroun!ing hair follicles*
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
12/37
"uruncles and
#arbunclesFuruncles are skin abscesses caused bystaphylococcal infection, which involve a
hair follicle and surrounding tissue.Carbuncles are clusters of furunclesconnected subcutaneously, causing
deeper suppuration and scarring. Theyare smaller and more superficial thansubcutaneous abscesses
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
13/37
#uruncles 'boils) are ten!er no!ules or pustules cause!
by staphylococcal infection* Carbuncles are clusters offuruncles that are subcutaneousl connecte!*
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
14/37'arbuncles
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
15/37
$reatment of
folliculitisBecause most folliculitis is cause! by S* aureus$ clin!amycin -.lotion or gel may be applie! topically bi! for / to -0 !ays*%lternatively$ ben1oyl pero i!e 2. ,ash may be use! ,hensho,ering for 2 to / !ays* " tensive cutaneous involvement may,arrant systemic therapy 'eg$ cephale in 320 to 200 mg po ti! to +i!for -0 !ays)*
If these measures !o not result in a cure$ or folliculitis recurs$pustules are 4ram staine! an! culture! to rule out gram(negative ormethicillin(resistant S* aureus 'M5S%) etiology$ an! nares areculture! to rule out nasal staphylococcal carriage* Potassiumhy!ro i!e ,et mount shoul! be !one on a plucke! hair to rule outfungal folliculitis*
Treatment for M5S% usually re+uires t,o oral antibiotics$ an! thechoice of therapeutic !rugs shoul! be base! on culture an!sensitivity reports*
Hot(tub folliculitis usually resolves ,ithout treatment* Ho,ever$a!e+uate chlorination of the hot tub is necessary to preventrecurrences an! to protect others from infection*
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
16/37
%idradenitis suppurativa
Hidradenitis suppurativa is a chronic,scarring inflammation of apocrine
glands of the axillae, groin, and aroundthe nipples and anus.
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
17/37
#ellulitisCellulitis is acute bacterial infection ofthe skin and subcutaneous tissue most
often caused by streptococci orstaphylococci.
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
18/37
$reatment of
cellulitisTreatment is ,ith antibiotics* #or most patients$ empirictreatment effective against both group % streptococci an! S*aureus is use!*
Oral therapy is usually a!e+uate ,ith !iclo acillin 320 mg orcephale in 200 mg po +i! for mil! infections* 6evoflo acin 200mg po once7!ay or mo iflo acin800 mg po once7!ay ,orks ,ell for patients ,ho are unlikely toa!here to multiple !aily !osing sche!ules*
#or more serious infections$ o acillin or nafcillin - g is given I9+ : h*
Immobili1ation an! elevation of the affecte! area help re!ucee!ema; cool$ ,et !ressings relieve local !iscomfort*
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
19/37
#utaneous &bscess
cutaneous abscess is a locali!edcollection of pus in the skin and may
occur on any skin surface.
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
20/37
'rysipelasErysipelas is a type of superficial cellulitis -ith dermallymphatic involvement.Erysipelas is characteri ed clinically by shiny, raised,indurated, and tender pla3ue"like lesions -ith distinct
margins. Erysipelas is most often caused by group $ !or rarelygroup ' or 4& 5"hemolytic streptococci and occursmost fre3uently on the legs and face.)ther causes " Staphylococcus aureus !including
methicillin"resistant S. aureus #MRS$%&, 6lebsiellapneumoniae, *aemophilus influen ae, Escherichiacoli.+t is commonly accompanied by high fever, chills, andmalaise. Erysipelas may be recurrent and may resultin chronic lymphedema.
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
21/37
"rysipelas is characteri1e! by shiny$ raise!$ in!urate!$an! ten!er pla+ue(like lesions ,ith !istinct margins* It ismost often cause! by
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
22/37
'ryt!rasmaErythrasma is an intertriginous infectionwith Corynebacterium minutissimum *Most common among patients withdiabetes and among people living in thetropics.
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
23/37
Impetigo and
'ct!yma"mpetigo is a superficial skin infectionwith crusting or bullae caused by
streptococci, staphylococci, or both .#cthyma is an ulcerative form ofimpetigo.
I ti 'B ll )i ( ll )
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
24/37
=on(bullous impetigo is a
superficial skin infection thatmanifests as clusters ofvesicles or pustules thatrupture an! !evelop a honey(colore! crust*
Bullous impetigo is a superficialskin infection that manifests asclusters of vesicles or pustules thatenlarge rapi!ly to form bullae* Thebullae burst an! e pose largerbases$ ,hich become covere! ,ithhoney(colore! varnish or crust*
Impetigo 'Bullous)Impetigo '=on(Bullous)
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
25/37
Ecthyma gangrenosum is abacterial skin infection !caused
by $seudomonas aeruginosa &that usually occurs in people-ith a compromised immunesystem.
Ecthyma is a skin infectionsimilar to impetigo, but more
deeply invasive. 7sually causedby a streptococcus infection ,ecthyma goes through the outerlayer !epidermis& to the deeperlayer !dermis& of skin, possiblycausing scars.
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
26/37
(ecroti)ing Subcutaneous Infection *(ecroti)ing "asciitis+
Typically caused by a mixture of aerobic and anaerobicorganisms that cause necrosis of subcutaneous tissue, usuallyincluding the fascia.
This infection most commonly affects the extremities and perineum. Affected tissues become red, hot, and swollen,resembling severe cellulitis.
Without timely treatment, the area becomes gangrenous. Patientsare acutely ill. Diagnosis is by history and examination and issupported by evidence of overwhelming infection.
Treatment involves antibiotics and surgical debridement.Prognosis is poor without early, aggressive treatment.
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
27/37
2ecrotising fasciitis
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
28/37
$reatment
8.Surgical debridement9. $ntibiotics:. $mputation if necessary
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
29/37
acterial Infection
of SkinLab. ,iagnosis
Specimen collection.1. Skin biopsy2. Skin swab3. Pus swab
4. Nasal / skin swab
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
30/37
Lab. ,iagnosisSuspecte! organismsImpetigo> 4roup $ Streptococcus, Staphylococcus
aureus#olliculitis> Staphylococcus aureus, $seudomonas
aeruginosa
#uruncles> Staphylococcus aureusCarbuncles> Staphylococcus aureusCellulitis> 4roup $ Streptococcus, Staphylococcus
aureus, Hemophilus influen!ae"rysipelas> %roup Streptococcus=ecroti1ing fasciitis : %roup Streptococcus,
Clostridium perfringens andother species, &acteroides fragilis,the anaerobes, #nterobacteriaceae,$seudomonas aeruginosa
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
31/37
Principles of t!erapy ofpyoderma
4ood personal hygieneManagement of predisposing factors
;ocal $ttend to traumas, (ressure, S-eating, 0ites Treat pre"e1isting dermatosis +nvestigate carrier sites< 2ose, $1illa, (erineum
SystemicTreatment of disease like DM2utritional deficiency+mmunodeficiency
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
32/37
Principles of t!erapy ofpyoderma
;ocal therapy'leaning -ith soap"-ater and -eak
6M2=> solution
Removal of crusts -ith 6M2=> solution
$pplication of antibacterial cream
Systemic therapy
$ntibiotics
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
33/37
Recurrent stap!ylococcal
infection(ersistent nasal carriage
$bnormal neutrophilic chemota1is
Deficient intracellular killing
+mmunodeficient status
D.M.
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
34/37
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
35/37
&ntibiotic ResistanceProfiles of -RS&
8== 0"lactam antibiotics> resistant to clindamycin and erythromycin
F resistant to ciproflo1acinC@ resistant to trimethoprimsulfametho1a ole:: resistant to tetracycline
: resistant to rifampin: resistant to fusidic acid9 resistant to mupirocin
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
36/37
-
7/25/2019 Bacterial Skin Infections_Course VIII.ppt
37/37