SlideShare a Scribd company logo
1 of 59
Download to read offline
Bacterial infections of the skin

By

Dr Hussein Abulfotouh
Consultant Dermatology & veneriology
Bacterial infection of the skin
Natural Defenses of the Skin
• Temperature less than 37 C
• Dry: usual infection sites are wet areas: skin
folds, armpit, groin

• Keratin
• Skin sloughing

• Sebum: low pH, high lipid content
• Sweat: - low pH, high salt,
- Lysozyme &toxic lipids

• Skin-associated lymphoid tissue (SALT)
• Resident microflora (mainly Gram positives)
Normal Skin Flora
• Propionibacterium acnes
• Corynebacterium sp.
• Staphylococci
– Staphylococcus epidermidis
– Staphylococcus aureus
• Streptococci sp.
• Candida albicans (yeast)
• Many others
Route of infection
1) Skin (pores, hair follicles).

2) Wounds (scratches, cuts, burns).
3) Insect & animal bites.
Primary Infections
• caused by a single pathogen, usually affect normal skin.
• Impetigo, folliculitis, and boils are common types.
• The most common primary skin pathogens are S
aureus β-hemolytic streptococci, and coryneform
bacteria.
• Organisms usually enter through a break in the skin.

Secondary Infections
• Secondary infections occur in skin that is already
diseased.
• Because of the underlying disease, the clinical picture
and course of these infections vary.
• Intertrigo and toe web infection are examples
Bacterial infection of the skin
Bacterial infection of the skin
Skin infections caused by S. aureus
I. Direct infection of skin and adjacent tissues
a.
b.
c.
d.
e.
f.

Impetigo
Ecthyma
Folliculitis
Furunculosis
Carbuncle
Sycosis barbae

II.Cutaneous disease due to effect of bacterial toxin
a.
b.

Staphylococcal scalded skin syndrome
Toxic shock syndrome
Skin infections caused by group A ßhemolytic streptococci
I. Direct infection of skin or subcutaneous tissue
a.
b.
c.
d.
e.

Impetigo (non bullous)
Ecthyma
Erysipelas
Cellulitis
Necrotizing fascitis

II. Secondary infection
Eczema infection
Skin and Soft Tissue Infections
1. Impetigo: Initially a vesicular infection that rapidly
evolves into pustules that rupture, with dried discharge
forming honey-colored crust on an erythematous base.

2. Ecthyma (Pustules): Begin as vesicles that
rupture, creating circular erythematous lesions with
adherent crusts.

3. Folliculitis: Inflammation at the opening of the hair
follicle that causes erythematouspapules and pustules
surrounding individual hairs.
4. Furuncle: Deep-seated inflammatory nodule with a
pustular center that develops around a hair follicle.
(painful, localized, abscess).

5. Carbuncle: Involvement of several adjacent
follicles, with pus discharging from multiple follicular
orifices.

6. Cutaneous abscesses:
Painful, fluctuant, red, tender swelling, on which may
rest a pustule.

7. Erysipelas: Erythema and swelling of the
cutaneous surface, involves the superficial dermis
8. Cellulitis: Erythematous, hot, swollen skin
with irregular edge (affects the deeper dermis and
subcutaneous fat).

9. Acne: Infection of sebaceous follicles with plugs of
keratin blocking the sebaceous canal, resulting in
“blackheads”.
10. Necrotizing fasciitis: Rapidly spreading cellulitis
with necrosis (skin and deeper fascia; may
involve muscle).
Begin with fever, systemic toxicity, severe pain
in the development of a painful, red swelling that
rapidly progress to necrosis of the subcutaneous
tissue and overlying skin.
Impetigo and Ecthyma
• Impetigo is a superficial skin infection with
crusting (non bullous) or bullae (bullous)
caused by streptococci, staphylococci, or both.
• Ecthyma is an ulcerative form of impetigo.
Crusted erosions on the arm
of a child.
The confluence of lesions in
the antecubital fossa
suggests prior atopic
dermatitis at the site that
became secondarily
infected
IMPETIGO (non-bullous)
IMPETIGO (bullous)

A large, single bulla with
surrounding erythema and
edema on the thumb of a
child; the bulla has ruptured
only in the center and clear
serum exudes from it.
Impetigo (Non-Bullous)

Non-bullous impetigo is a
superficial skin infection that
manifests as clusters of vesicles or
pustules that rupture and develop
a honey-colored crust.

Impetigo (Bullous)

Bullous impetigo is a superficial skin
infection that manifests as clusters of
vesicles or pustules that enlarge rapidly
to form bullae. The bullae burst and
expose larger bases, which become
covered with honey-colored varnish or
crust.
Ecthyma is a skin infection
similar to impetigo, but more
deeply invasive. Usually caused by
a streptococcus
infection, ecthyma goes through
the outer layer (epidermis) to the
deeper layer (dermis) of
skin, possibly causing scars.

Ecthyma gangrenosum is a
bacterial skin infection (caused
by Pseudomonas aeruginosa)
that usually occurs in immunocompromised individuals
Folliculitis
• Folliculitis is a bacterial infection of hair follicles.
• It is usually caused by Staphylococcus aureus but
occasionally Pseudomonas aeruginosa (hot-tub
folliculitis)
• The bacteria is commonly found in contaminated
whirlpools, hot tubs or physiotherapy pools
• Children tend to get hot tub folliculitis more
• Hot-tub folliculitis occurs because of inadequate
treatment of water with chlorine or bromine.
Bacterial infection of the skin
FOLLICULITIS

Folliculitis manifests as superficial pustules or
inflammatory nodules surrounding hair follicles.

Superficial erythematous
papules & crusts of hair
follicles in the beard area ,
aggravated by shaving.
Furuncles and Carbuncles
• Furuncles are skin abscesses caused by
staphylococcal infection, which involve a hair
follicle and surrounding tissue.

• Carbuncles are clusters of furuncles connected
subcutaneously, causing deeper suppuration
and scarring. They are smaller and more
superficial than subcutaneous abscesses
FURUNCLE
Furuncles (boils) are tender nodules or pustules caused by staphylococcal infection.
Carbuncles are clusters of furuncles that are subcutaneously connected.
CARBUNCLE
Staph aureus - Large, inflammatory plaque studded with multiple pustules, some
have ruptured, draining pus, on the nape of the neck. This very painful area is
surrounded by erythema and edema, extends down to fascia, formed from a
confluence of many furuncles.
Carbuncles
Cellulitis
• Cellulitis is an acute bacterial infection of the skin
and subcutaneous tissue most often caused by

streptococci or staphylococci.
• Some people are at risk for infection by other types of
bacteria. They include people with weak immune
system, and those who handle fish, meat, poultry, or soil
without using gloves.

• Cellulitis can occur anywhere on the body. In
adults, it often occurs on the legs, face, or arms. In
children, it is most common on the face or around
the anus. An infection on the face could lead to a
dangerous eye infection.
CELLULITIS

Portal of entry of infection is seen
on the lateral thigh with necrosis
of skin; infection has extended
mainly proximally from this site.
Erysipelas
• Erysipelas is a type of superficial cellulitis with dermal
lymphatic involvement.
• It is characterized clinically by shiny, raised, indurated and tender
plaque-like lesions with distinct margins (you can see a clear
border between normal and infected skin).
• Erysipelas is most often caused by group A β-hemolytic
streptococci and occurs most frequently on the legs and face.
• Other causes : Staphylococcus aureus (including
MRSA), Klebsiella pneumoniae, H.influenzae, E. coli).
• It is commonly accompanied by high fever, chills, and malaise.
Erysipelas may be recurrent and may result in chronic
lymphedema.
ERYSIPELAS
Cutaneous Abscess
• A cutaneous abscess is a localized collection of
pus in the skin and may occur on any skin surface.
Necrotizing Subcutaneous Infection

(Necrotizing Fasciitis)
• Typically caused by a mixture of aerobic &
anaerobic organisms that cause necrosis of
subcutaneous tissue, usually including 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. Diagnosis is by history and examination.

• Treatment involves: antibiotics,surgical
debridement, Amputation if necessary
• Prognosis is poor without early, aggressive treatment.
Necrotizing Fasciitis “Flesh Eating Strep”
Streptococcus pyogenes (Group A β hemolytic Streptococci (GABHS) is
the causative agent

• Necrotizing fasciitis:
The disease starts as localized infection that rapidly
spreading cellulitis with necrosis (skin and deeper
fascia; may involve muscle).
• Begin with fever, systemic toxicity and severe pain
• The development of a painful, red swelling that rapidly
progress to necrosis of the subcutaneous tissue and
overlying skin.
• The Invasive & spreading cellulitis may lead to

loss of limb
• May lead to toxic shock
NECROTIZING FASCIITIS
Acne
Acne
• Most common skin disease in humans

• Propionibacterium acnes: Gram +ve rod ,causative agent
• Pathogenesis: bacteria digest sebum , Attracts neutrophils
- Neutrophil digestive enzymes cause lesions, “pus pockets”
• Obstruction of sebaceous follicles (oil glands)
• Open comedones or closed comedones
• Usually on the face, chest, back

• Risk factors:
– Stressful events (hormonal changes)
– Friction acne
– Oil based cosmetics

– NO correlation between chocolate, chips or colas
(No effects of diet)
Acne Treatments
• Tx: topical +/or oral
antibiotics.
• Benzoyl peroxide dries
plugged follicles, kills
microbes
• Tetracycline (antibiotic)
• Accutane – inhibits sebum
formation
HIDRADENITIS SUPPURATIVA
 Hidradenitis suppurativa is a
chronic, suppurative recurring
inflammatory disease of apocrine
gland follicles.
 Commoner in females specially
after puppetry.
 Sites: axillae, around the
nipples, under the
breast, perineum, groin, buttocks, n
eck and scalp.
 lesions:
nodules, abcesses, scarring,sinus
tract formation.
HIDRADENITIS SUPPURATIVA
Erythrasma
• Erythrasma is a bacterial skin infection that occurs in areas where
skin touches skin, like between toes, in armpits, or groin

• This intertriginous infection is caused by Corynebacterium
minutissimum.
• Most common among patients with diabetes.
• Erythrasma is sometimes mistaken with fungal infections.
• If you have such picture that’s not responding to anti-fungal therapy, see
your doctor because erythrasma is easily treated with the proper
antibiotics
MRSA skin infections
•
•
•
•
•
•
•
•
•

•

Methicillin-resistant Staphylococcus aureus
“super-bug” – caused by staph, antibiotics abuse
Outwits all but the most powerful of drugs – vancomycin
Enters through cuts & wounds
Types: CA (community acquired) or HA (Hospital acquired)
S/S: small red bumps that resemble pimples, quickly turn to
painful abscesses that can burrow deep into the body, swelling,
redness, pus
Risk Factors: recent hospitalization, long-term care, recent
antiobiotic use, young age, contact sports, sharing towels, weak
immune system, living in groups, health-care workers
Dx: Tissue sample – 48hrs
Tx: trial & error with strong antiobiotics
Prevention: WASH HANDS, surfaces, cover wounds,
use only personal items
MRSA skin infection
Recurrent skin infections
• Recurrent skin infections should raise suspicion
of colonization
– Staphylococcal nasal carriage
– Resistant strains of bacteria (eg. MRSA),
– Cancer
– Poorly controlled diabetes
– Other reasons for immuno-suppression
(eg, HIV, hepatitis, advanced age,….).
Staph. carriage elimination
• Nasal & perineal care

• Rifampicin 600 mg/d 7-10 days
• Clindamycin 150 mg/d 3 months

• Topical mupirocin
• Replacement of microflora with a less

pathogenic strains of S.aurus (strain 502)
Staphylococcal Scalded Skin
Syndrome(SSSS)
Mechanism: Exfoliatins
• SSSS also called Lyell's
disease or toxic epidermal
necrolysis, starts as a localized
lesion, followed by
widespread erythema and
exfoliation of the skin.
• This disorder is caused by
staphylococcal strain which
elaboratse an epidermolytic
toxin. The disease is more
common in infants than in
adults
Toxic Shock Syndrome
Mechanism: TSST-1
Localized growth of
toxigenic strains in vagina
or wound.
- Starts abruptly with
fever, hypotension, and
diffuse macular
erythematous rash.
Multiple organs & systems
are involved, entire body
skin desquamates.
Laboratory Diagnosis of Bacterial
Infections of Skin (1)
Specimen collection:
1.
2.
3.
4.

Skin biopsy
Skin swab
Pus swab
Nasal swab

N.B.
When pustules or vesicles are present, the roof or crust
is removed with a sterile surgical blade. Pus or
exudate is spread as thinly as possible on a clear
glass slide for Gram staining
Laboratory Diagnosis of Bacterial
Infections of Skin (2)
Suspected organisms
• Impetigo: Group A Streptococcus, Staphylococcus
aureus
• Folliculitis: Staphylococcus aureus, Pseudomonas
aeruginosa
• Furuncles: Staphylococcus aureus
• Carbuncles: Staphylococcus aureus
• Cellulitis: Group A Streptococcus, Staphylococcus
aureus, Hemophilus influenzae
• Erysipelas: Group A Streptococcus
• Necrotizing fasciitis: Group A Streptococcus,
Clostridium perfringens and
other species, Bacteroides fragilis,
the anaerobes, Enterobacteriaceae,
Pseudomonas aeruginosa
Laboratory Diagnosis of Bacterial
Infections of Skin (3)
1. Clinical specimen: Scrape the base of the skin lesion with a swab.
Gram stain: Gram (+) cocci in clusters (or in chains)
2. Culture: Blood Agar (for both), Mannitol Salt Agar (for staph)
Identification: catalase , Coagulase , mannitol fermentation
On blood agar : both S. aureus & strept pyogens produces beta
hemolysis.

Tube Coagulase test

Catalasa test
Laboratory Diagnosis of Bacterial
Infections of Skin (4)
2. Mannitol salts agar (MSA):high salt(7.5) inhibits
the grow of most other organisms, S. aureus
ferments mannitol, the acid produced turns the
colonies yellow.
Principles of therapy of pyoderma
• Good personal hygiene
• Management of predisposing factors
• Aluminum chloride, a drying agent, inhibits overgrowth of
opportunistic bacteria in foot, perineal, and axillary areas.
• Keratinolytic agents (e.g., topical salicylates) remove
hyperkeratotic lesions that harbor pathogens, improving
the exposure of the infected skin surface to other topical
treatments

Systemic
• Treatment of disease like DM
• Nutritional deficiency
• Immunodeficiency
Principles of therapy of pyoderma
• Local therapy
– Cleaning with soap-water and weak KMN04
solution
– Removal of crusts with KMN04 solution
– Application of antibacterial creams or ointments

• Systemic therapy
– Antibiotics
Topical Treatment
• Topical antibiotics contain a combination of:

neomycin, bacitracin, and polymyxin.

• Some newer preparations contain:

mupirocin, gramicidin, or erythromycin, and
others combine these antibiotics with steroids.

Systemic Therapy
• Systemic treatment with antibiotics is mandatory for
extensive pyoderma.
• Systemic antibiotics can be administered orally or
parenterally. Oral therapy is sufficient for most
extensive dermal infections, but the parenteral route
is preferred for severe infections.
CHRONIC BACTERIAL SKIN INFECTION
• Tuberculosis: caused by mycobacterium tuberculosis
• Etiology:
• Primary inf. : acquiring the bacilli for the 1st time
• Post primary inf. occurs in pt with previous TB or
previous BCG vaccination.
• A- Localized: as lupus vulgaris, scrofuloderma and TB
verrucosa cutis.
• B- General: as miliary lesions, in pt with miliary TB &
immune suppressed, multiple TB abscesses
• C- Tuberculide
1. papulonecrotic tuberculide.
2. Lichen scrofulosorm.
3. Erythema induratum.
• primary TB infection
[tuberculous chancre]
• Lupus vulgaris

Scrofuloderm
• Tuberculous warts:
[tuberculosis
verrucosa cutis]
• Orificial TB
• Papulonecrotic
tuberculide

Lichen scrofulosorum
Erythema induratum
Lupus vulgaris
•
•
•
•
•

Commonest 1ry infection
Good natural immunity
Heamatogenous spread
Apple jelly nodule--scar
Tuberculoid granuloma

Mx: bx, AFB
Local ttt
Anti TB
Diagnosis of skin TB
• confirmed either by find the microorganism in
culture media (never to be seen in skin lesion)
• PCR
• Presence of acid fast bacilli (by ZN stain)
• History, positive tuberculin test, presence of
caseating granuloma on histopathology and
therapeutic response to anti-TB drugs
Bacterial infection of the skin

More Related Content

What's hot (20)

Skin lesions
Skin lesionsSkin lesions
Skin lesions
 
Common Viral Skin Diseases
Common Viral Skin DiseasesCommon Viral Skin Diseases
Common Viral Skin Diseases
 
Skin disorders
Skin disordersSkin disorders
Skin disorders
 
Pityriasis versicolor
Pityriasis versicolorPityriasis versicolor
Pityriasis versicolor
 
Folliculitis,boil( Furuncle), carbuncle
Folliculitis,boil( Furuncle), carbuncle Folliculitis,boil( Furuncle), carbuncle
Folliculitis,boil( Furuncle), carbuncle
 
1.1.2. viral infections of skin [compatibility mode]
1.1.2. viral infections of skin [compatibility mode]1.1.2. viral infections of skin [compatibility mode]
1.1.2. viral infections of skin [compatibility mode]
 
Seborrheic dermatitis
Seborrheic dermatitisSeborrheic dermatitis
Seborrheic dermatitis
 
Tinea versicolor
Tinea versicolorTinea versicolor
Tinea versicolor
 
Superficial Fungal Infections
Superficial  Fungal InfectionsSuperficial  Fungal Infections
Superficial Fungal Infections
 
Urticaria
UrticariaUrticaria
Urticaria
 
Tinea Capitis
Tinea CapitisTinea Capitis
Tinea Capitis
 
Tinea dermatophytes
Tinea   dermatophytesTinea   dermatophytes
Tinea dermatophytes
 
Skin fungal infection
Skin fungal infectionSkin fungal infection
Skin fungal infection
 
Morphology of skin lesions
Morphology of skin lesionsMorphology of skin lesions
Morphology of skin lesions
 
Dermatophytosis, raghu
Dermatophytosis, raghuDermatophytosis, raghu
Dermatophytosis, raghu
 
Molluscum contagiosum
Molluscum contagiosumMolluscum contagiosum
Molluscum contagiosum
 
11. Psoriasis
11. Psoriasis11. Psoriasis
11. Psoriasis
 
Staphylococcal & streptococcal skin infections
Staphylococcal & streptococcal skin infectionsStaphylococcal & streptococcal skin infections
Staphylococcal & streptococcal skin infections
 
Erythroderma
ErythrodermaErythroderma
Erythroderma
 
Boils
BoilsBoils
Boils
 

Similar to Bacterial infection of the skin

Dr hussein, bacterial infec of the skin
Dr hussein, bacterial infec of the skinDr hussein, bacterial infec of the skin
Dr hussein, bacterial infec of the skinMEEQAT HOSPITAL
 
Bacterial skin infections
Bacterial skin infectionsBacterial skin infections
Bacterial skin infectionsMEEQAT HOSPITAL
 
Skin disease ppt for nursing student
Skin disease ppt for nursing studentSkin disease ppt for nursing student
Skin disease ppt for nursing studentPatel Dharmendra
 
Skin conditions of surgical Importance.pptx
Skin conditions of surgical Importance.pptxSkin conditions of surgical Importance.pptx
Skin conditions of surgical Importance.pptxDakaneMaalim
 
Skin and Soft Tissue Infection.pptx
Skin and Soft Tissue Infection.pptxSkin and Soft Tissue Infection.pptx
Skin and Soft Tissue Infection.pptxSitiHajar643369
 
2. integument system...pptx
2. integument system...pptx2. integument system...pptx
2. integument system...pptxSuperior college
 
dermatology.Bact .inf 5th.(dr.ali)
dermatology.Bact .inf 5th.(dr.ali)dermatology.Bact .inf 5th.(dr.ali)
dermatology.Bact .inf 5th.(dr.ali)student
 
Overview of Skin infections- July 2022.pdf
Overview of Skin infections- July 2022.pdfOverview of Skin infections- July 2022.pdf
Overview of Skin infections- July 2022.pdfAdamu Mohammad
 
disorder of skin viji.pptx
disorder of skin viji.pptxdisorder of skin viji.pptx
disorder of skin viji.pptxVijiM14
 
Bacterial and Viral skin infection.pptx
Bacterial  and Viral skin infection.pptxBacterial  and Viral skin infection.pptx
Bacterial and Viral skin infection.pptxKiflom hagos
 
Cellulitis
CellulitisCellulitis
CellulitisPriya
 
COMMON SKIN INFECTIONS IN CHILDREN.pptx
COMMON SKIN INFECTIONS IN CHILDREN.pptxCOMMON SKIN INFECTIONS IN CHILDREN.pptx
COMMON SKIN INFECTIONS IN CHILDREN.pptxLordInnoz
 
Final ppt on fungal diseases
Final ppt on fungal diseasesFinal ppt on fungal diseases
Final ppt on fungal diseasesSafeena Sidiq
 
softtissueinfections.pptx
softtissueinfections.pptxsofttissueinfections.pptx
softtissueinfections.pptxmasoom parwez
 
Bacterial , viral, parasitic infections
Bacterial , viral, parasitic infectionsBacterial , viral, parasitic infections
Bacterial , viral, parasitic infectionsMustafa Al Mously
 
Bacterial skin infections.pptx
Bacterial skin infections.pptxBacterial skin infections.pptx
Bacterial skin infections.pptxabd18m0108
 

Similar to Bacterial infection of the skin (20)

Dr hussein, bacterial infec of the skin
Dr hussein, bacterial infec of the skinDr hussein, bacterial infec of the skin
Dr hussein, bacterial infec of the skin
 
Bacterial skin infections
Bacterial skin infectionsBacterial skin infections
Bacterial skin infections
 
LECTURE ON SKIN DISEASES.pptx
LECTURE ON SKIN DISEASES.pptxLECTURE ON SKIN DISEASES.pptx
LECTURE ON SKIN DISEASES.pptx
 
Skin disease ppt for nursing student
Skin disease ppt for nursing studentSkin disease ppt for nursing student
Skin disease ppt for nursing student
 
Skin conditions of surgical Importance.pptx
Skin conditions of surgical Importance.pptxSkin conditions of surgical Importance.pptx
Skin conditions of surgical Importance.pptx
 
Skin and Soft Tissue Infection.pptx
Skin and Soft Tissue Infection.pptxSkin and Soft Tissue Infection.pptx
Skin and Soft Tissue Infection.pptx
 
2. integument system...pptx
2. integument system...pptx2. integument system...pptx
2. integument system...pptx
 
dermatology.Bact .inf 5th.(dr.ali)
dermatology.Bact .inf 5th.(dr.ali)dermatology.Bact .inf 5th.(dr.ali)
dermatology.Bact .inf 5th.(dr.ali)
 
Overview of Skin infections- July 2022.pdf
Overview of Skin infections- July 2022.pdfOverview of Skin infections- July 2022.pdf
Overview of Skin infections- July 2022.pdf
 
disorder of skin viji.pptx
disorder of skin viji.pptxdisorder of skin viji.pptx
disorder of skin viji.pptx
 
Bacterial and Viral skin infection.pptx
Bacterial  and Viral skin infection.pptxBacterial  and Viral skin infection.pptx
Bacterial and Viral skin infection.pptx
 
Bacterial infections
Bacterial infectionsBacterial infections
Bacterial infections
 
Skin and Soft tissue infections
Skin and Soft  tissue  infectionsSkin and Soft  tissue  infections
Skin and Soft tissue infections
 
Cellulitis
CellulitisCellulitis
Cellulitis
 
COMMON SKIN INFECTIONS IN CHILDREN.pptx
COMMON SKIN INFECTIONS IN CHILDREN.pptxCOMMON SKIN INFECTIONS IN CHILDREN.pptx
COMMON SKIN INFECTIONS IN CHILDREN.pptx
 
Final ppt on fungal diseases
Final ppt on fungal diseasesFinal ppt on fungal diseases
Final ppt on fungal diseases
 
softtissueinfections.pptx
softtissueinfections.pptxsofttissueinfections.pptx
softtissueinfections.pptx
 
Bacterial , viral, parasitic infections
Bacterial , viral, parasitic infectionsBacterial , viral, parasitic infections
Bacterial , viral, parasitic infections
 
Dermatology 5th year, 5ht lecture (Dr. Ali El-Ethawi)
Dermatology 5th year, 5ht lecture (Dr. Ali El-Ethawi)Dermatology 5th year, 5ht lecture (Dr. Ali El-Ethawi)
Dermatology 5th year, 5ht lecture (Dr. Ali El-Ethawi)
 
Bacterial skin infections.pptx
Bacterial skin infections.pptxBacterial skin infections.pptx
Bacterial skin infections.pptx
 

More from MEEQAT HOSPITAL

Updated conscious sedation course.ppt
Updated conscious sedation course.pptUpdated conscious sedation course.ppt
Updated conscious sedation course.pptMEEQAT HOSPITAL
 
Blood Bank Lecture .pptx
Blood Bank Lecture .pptxBlood Bank Lecture .pptx
Blood Bank Lecture .pptxMEEQAT HOSPITAL
 
Sepsis and septic shock guidelines 2021. part 1
Sepsis and septic shock guidelines 2021. part 1Sepsis and septic shock guidelines 2021. part 1
Sepsis and septic shock guidelines 2021. part 1MEEQAT HOSPITAL
 
Sepsis hemodynamic update part two
Sepsis hemodynamic update      part twoSepsis hemodynamic update      part two
Sepsis hemodynamic update part twoMEEQAT HOSPITAL
 
sepsis SSC 2021 Updates Ventilation and additional therapy
sepsis SSC 2021 Updates Ventilation and additional therapysepsis SSC 2021 Updates Ventilation and additional therapy
sepsis SSC 2021 Updates Ventilation and additional therapyMEEQAT HOSPITAL
 
Surviving sepsis compaign (adults) Guidelines updates 2021. “Long Term Outcom...
Surviving sepsis compaign (adults)Guidelines updates 2021.“Long Term Outcom...Surviving sepsis compaign (adults)Guidelines updates 2021.“Long Term Outcom...
Surviving sepsis compaign (adults) Guidelines updates 2021. “Long Term Outcom...MEEQAT HOSPITAL
 
Medication error, nursing responsibility
Medication error, nursing responsibilityMedication error, nursing responsibility
Medication error, nursing responsibilityMEEQAT HOSPITAL
 
Continuous renal replacement therapy crrt
Continuous renal replacement therapy crrtContinuous renal replacement therapy crrt
Continuous renal replacement therapy crrtMEEQAT HOSPITAL
 
Deep venous thrombosis dvt
Deep venous thrombosis dvtDeep venous thrombosis dvt
Deep venous thrombosis dvtMEEQAT HOSPITAL
 
Chest intubation indications,precautions and management
Chest intubation indications,precautions and managementChest intubation indications,precautions and management
Chest intubation indications,precautions and managementMEEQAT HOSPITAL
 
Covid19 corona management -كوفيد19
Covid19 corona management -كوفيد19Covid19 corona management -كوفيد19
Covid19 corona management -كوفيد19MEEQAT HOSPITAL
 
Conscious sedation course
Conscious sedation courseConscious sedation course
Conscious sedation courseMEEQAT HOSPITAL
 
Medical permission for patient
Medical permission for patientMedical permission for patient
Medical permission for patientMEEQAT HOSPITAL
 

More from MEEQAT HOSPITAL (20)

Updated conscious sedation course.ppt
Updated conscious sedation course.pptUpdated conscious sedation course.ppt
Updated conscious sedation course.ppt
 
fatal asthma.pptx
fatal asthma.pptxfatal asthma.pptx
fatal asthma.pptx
 
Blood Bank Lecture .pptx
Blood Bank Lecture .pptxBlood Bank Lecture .pptx
Blood Bank Lecture .pptx
 
Post covid -19 syndrome
Post covid -19 syndromePost covid -19 syndrome
Post covid -19 syndrome
 
Sepsis and septic shock guidelines 2021. part 1
Sepsis and septic shock guidelines 2021. part 1Sepsis and septic shock guidelines 2021. part 1
Sepsis and septic shock guidelines 2021. part 1
 
Sepsis hemodynamic update part two
Sepsis hemodynamic update      part twoSepsis hemodynamic update      part two
Sepsis hemodynamic update part two
 
sepsis SSC 2021 Updates Ventilation and additional therapy
sepsis SSC 2021 Updates Ventilation and additional therapysepsis SSC 2021 Updates Ventilation and additional therapy
sepsis SSC 2021 Updates Ventilation and additional therapy
 
Sepsis scoring
Sepsis  scoringSepsis  scoring
Sepsis scoring
 
Surviving sepsis compaign (adults) Guidelines updates 2021. “Long Term Outcom...
Surviving sepsis compaign (adults)Guidelines updates 2021.“Long Term Outcom...Surviving sepsis compaign (adults)Guidelines updates 2021.“Long Term Outcom...
Surviving sepsis compaign (adults) Guidelines updates 2021. “Long Term Outcom...
 
Medication error, nursing responsibility
Medication error, nursing responsibilityMedication error, nursing responsibility
Medication error, nursing responsibility
 
Continuous renal replacement therapy crrt
Continuous renal replacement therapy crrtContinuous renal replacement therapy crrt
Continuous renal replacement therapy crrt
 
Deep venous thrombosis dvt
Deep venous thrombosis dvtDeep venous thrombosis dvt
Deep venous thrombosis dvt
 
Bed sore management
Bed sore managementBed sore management
Bed sore management
 
Chest intubation indications,precautions and management
Chest intubation indications,precautions and managementChest intubation indications,precautions and management
Chest intubation indications,precautions and management
 
Portable ventilator
Portable ventilatorPortable ventilator
Portable ventilator
 
Covid19 corona management -كوفيد19
Covid19 corona management -كوفيد19Covid19 corona management -كوفيد19
Covid19 corona management -كوفيد19
 
Sedation
SedationSedation
Sedation
 
Conscious sedation course
Conscious sedation courseConscious sedation course
Conscious sedation course
 
Electronic medica file
Electronic medica fileElectronic medica file
Electronic medica file
 
Medical permission for patient
Medical permission for patientMedical permission for patient
Medical permission for patient
 

Recently uploaded

Patient Counselling. Definition of patient counseling; steps involved in pati...
Patient Counselling. Definition of patient counseling; steps involved in pati...Patient Counselling. Definition of patient counseling; steps involved in pati...
Patient Counselling. Definition of patient counseling; steps involved in pati...raviapr7
 
In - Vivo and In - Vitro Correlation.pptx
In - Vivo and In - Vitro Correlation.pptxIn - Vivo and In - Vitro Correlation.pptx
In - Vivo and In - Vitro Correlation.pptxAditiChauhan701637
 
How to Use api.constrains ( ) in Odoo 17
How to Use api.constrains ( ) in Odoo 17How to Use api.constrains ( ) in Odoo 17
How to Use api.constrains ( ) in Odoo 17Celine George
 
Education and training program in the hospital APR.pptx
Education and training program in the hospital APR.pptxEducation and training program in the hospital APR.pptx
Education and training program in the hospital APR.pptxraviapr7
 
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdfMaximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdfTechSoup
 
Practical Research 1 Lesson 9 Scope and delimitation.pptx
Practical Research 1 Lesson 9 Scope and delimitation.pptxPractical Research 1 Lesson 9 Scope and delimitation.pptx
Practical Research 1 Lesson 9 Scope and delimitation.pptxKatherine Villaluna
 
Quality Assurance_GOOD LABORATORY PRACTICE
Quality Assurance_GOOD LABORATORY PRACTICEQuality Assurance_GOOD LABORATORY PRACTICE
Quality Assurance_GOOD LABORATORY PRACTICESayali Powar
 
AUDIENCE THEORY -- FANDOM -- JENKINS.pptx
AUDIENCE THEORY -- FANDOM -- JENKINS.pptxAUDIENCE THEORY -- FANDOM -- JENKINS.pptx
AUDIENCE THEORY -- FANDOM -- JENKINS.pptxiammrhaywood
 
Benefits & Challenges of Inclusive Education
Benefits & Challenges of Inclusive EducationBenefits & Challenges of Inclusive Education
Benefits & Challenges of Inclusive EducationMJDuyan
 
Drug Information Services- DIC and Sources.
Drug Information Services- DIC and Sources.Drug Information Services- DIC and Sources.
Drug Information Services- DIC and Sources.raviapr7
 
Ultra structure and life cycle of Plasmodium.pptx
Ultra structure and life cycle of Plasmodium.pptxUltra structure and life cycle of Plasmodium.pptx
Ultra structure and life cycle of Plasmodium.pptxDr. Asif Anas
 
Presentation on the Basics of Writing. Writing a Paragraph
Presentation on the Basics of Writing. Writing a ParagraphPresentation on the Basics of Writing. Writing a Paragraph
Presentation on the Basics of Writing. Writing a ParagraphNetziValdelomar1
 
How to Solve Singleton Error in the Odoo 17
How to Solve Singleton Error in the  Odoo 17How to Solve Singleton Error in the  Odoo 17
How to Solve Singleton Error in the Odoo 17Celine George
 
General views of Histopathology and step
General views of Histopathology and stepGeneral views of Histopathology and step
General views of Histopathology and stepobaje godwin sunday
 
CHUYÊN ĐỀ DẠY THÊM TIẾNG ANH LỚP 11 - GLOBAL SUCCESS - NĂM HỌC 2023-2024 - HK...
CHUYÊN ĐỀ DẠY THÊM TIẾNG ANH LỚP 11 - GLOBAL SUCCESS - NĂM HỌC 2023-2024 - HK...CHUYÊN ĐỀ DẠY THÊM TIẾNG ANH LỚP 11 - GLOBAL SUCCESS - NĂM HỌC 2023-2024 - HK...
CHUYÊN ĐỀ DẠY THÊM TIẾNG ANH LỚP 11 - GLOBAL SUCCESS - NĂM HỌC 2023-2024 - HK...Nguyen Thanh Tu Collection
 
CAULIFLOWER BREEDING 1 Parmar pptx
CAULIFLOWER BREEDING 1 Parmar pptxCAULIFLOWER BREEDING 1 Parmar pptx
CAULIFLOWER BREEDING 1 Parmar pptxSaurabhParmar42
 
Patterns of Written Texts Across Disciplines.pptx
Patterns of Written Texts Across Disciplines.pptxPatterns of Written Texts Across Disciplines.pptx
Patterns of Written Texts Across Disciplines.pptxMYDA ANGELICA SUAN
 
M-2- General Reactions of amino acids.pptx
M-2- General Reactions of amino acids.pptxM-2- General Reactions of amino acids.pptx
M-2- General Reactions of amino acids.pptxDr. Santhosh Kumar. N
 
What is the Future of QuickBooks DeskTop?
What is the Future of QuickBooks DeskTop?What is the Future of QuickBooks DeskTop?
What is the Future of QuickBooks DeskTop?TechSoup
 

Recently uploaded (20)

Patient Counselling. Definition of patient counseling; steps involved in pati...
Patient Counselling. Definition of patient counseling; steps involved in pati...Patient Counselling. Definition of patient counseling; steps involved in pati...
Patient Counselling. Definition of patient counseling; steps involved in pati...
 
In - Vivo and In - Vitro Correlation.pptx
In - Vivo and In - Vitro Correlation.pptxIn - Vivo and In - Vitro Correlation.pptx
In - Vivo and In - Vitro Correlation.pptx
 
How to Use api.constrains ( ) in Odoo 17
How to Use api.constrains ( ) in Odoo 17How to Use api.constrains ( ) in Odoo 17
How to Use api.constrains ( ) in Odoo 17
 
Education and training program in the hospital APR.pptx
Education and training program in the hospital APR.pptxEducation and training program in the hospital APR.pptx
Education and training program in the hospital APR.pptx
 
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdfMaximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
 
Practical Research 1 Lesson 9 Scope and delimitation.pptx
Practical Research 1 Lesson 9 Scope and delimitation.pptxPractical Research 1 Lesson 9 Scope and delimitation.pptx
Practical Research 1 Lesson 9 Scope and delimitation.pptx
 
Quality Assurance_GOOD LABORATORY PRACTICE
Quality Assurance_GOOD LABORATORY PRACTICEQuality Assurance_GOOD LABORATORY PRACTICE
Quality Assurance_GOOD LABORATORY PRACTICE
 
AUDIENCE THEORY -- FANDOM -- JENKINS.pptx
AUDIENCE THEORY -- FANDOM -- JENKINS.pptxAUDIENCE THEORY -- FANDOM -- JENKINS.pptx
AUDIENCE THEORY -- FANDOM -- JENKINS.pptx
 
Benefits & Challenges of Inclusive Education
Benefits & Challenges of Inclusive EducationBenefits & Challenges of Inclusive Education
Benefits & Challenges of Inclusive Education
 
Drug Information Services- DIC and Sources.
Drug Information Services- DIC and Sources.Drug Information Services- DIC and Sources.
Drug Information Services- DIC and Sources.
 
Ultra structure and life cycle of Plasmodium.pptx
Ultra structure and life cycle of Plasmodium.pptxUltra structure and life cycle of Plasmodium.pptx
Ultra structure and life cycle of Plasmodium.pptx
 
Presentation on the Basics of Writing. Writing a Paragraph
Presentation on the Basics of Writing. Writing a ParagraphPresentation on the Basics of Writing. Writing a Paragraph
Presentation on the Basics of Writing. Writing a Paragraph
 
How to Solve Singleton Error in the Odoo 17
How to Solve Singleton Error in the  Odoo 17How to Solve Singleton Error in the  Odoo 17
How to Solve Singleton Error in the Odoo 17
 
General views of Histopathology and step
General views of Histopathology and stepGeneral views of Histopathology and step
General views of Histopathology and step
 
Prelims of Kant get Marx 2.0: a general politics quiz
Prelims of Kant get Marx 2.0: a general politics quizPrelims of Kant get Marx 2.0: a general politics quiz
Prelims of Kant get Marx 2.0: a general politics quiz
 
CHUYÊN ĐỀ DẠY THÊM TIẾNG ANH LỚP 11 - GLOBAL SUCCESS - NĂM HỌC 2023-2024 - HK...
CHUYÊN ĐỀ DẠY THÊM TIẾNG ANH LỚP 11 - GLOBAL SUCCESS - NĂM HỌC 2023-2024 - HK...CHUYÊN ĐỀ DẠY THÊM TIẾNG ANH LỚP 11 - GLOBAL SUCCESS - NĂM HỌC 2023-2024 - HK...
CHUYÊN ĐỀ DẠY THÊM TIẾNG ANH LỚP 11 - GLOBAL SUCCESS - NĂM HỌC 2023-2024 - HK...
 
CAULIFLOWER BREEDING 1 Parmar pptx
CAULIFLOWER BREEDING 1 Parmar pptxCAULIFLOWER BREEDING 1 Parmar pptx
CAULIFLOWER BREEDING 1 Parmar pptx
 
Patterns of Written Texts Across Disciplines.pptx
Patterns of Written Texts Across Disciplines.pptxPatterns of Written Texts Across Disciplines.pptx
Patterns of Written Texts Across Disciplines.pptx
 
M-2- General Reactions of amino acids.pptx
M-2- General Reactions of amino acids.pptxM-2- General Reactions of amino acids.pptx
M-2- General Reactions of amino acids.pptx
 
What is the Future of QuickBooks DeskTop?
What is the Future of QuickBooks DeskTop?What is the Future of QuickBooks DeskTop?
What is the Future of QuickBooks DeskTop?
 

Bacterial infection of the skin

  • 1. Bacterial infections of the skin By Dr Hussein Abulfotouh Consultant Dermatology & veneriology
  • 3. Natural Defenses of the Skin • Temperature less than 37 C • Dry: usual infection sites are wet areas: skin folds, armpit, groin • Keratin • Skin sloughing • Sebum: low pH, high lipid content • Sweat: - low pH, high salt, - Lysozyme &toxic lipids • Skin-associated lymphoid tissue (SALT) • Resident microflora (mainly Gram positives)
  • 4. Normal Skin Flora • Propionibacterium acnes • Corynebacterium sp. • Staphylococci – Staphylococcus epidermidis – Staphylococcus aureus • Streptococci sp. • Candida albicans (yeast) • Many others
  • 5. Route of infection 1) Skin (pores, hair follicles). 2) Wounds (scratches, cuts, burns). 3) Insect & animal bites.
  • 6. Primary Infections • caused by a single pathogen, usually affect normal skin. • Impetigo, folliculitis, and boils are common types. • The most common primary skin pathogens are S aureus β-hemolytic streptococci, and coryneform bacteria. • Organisms usually enter through a break in the skin. Secondary Infections • Secondary infections occur in skin that is already diseased. • Because of the underlying disease, the clinical picture and course of these infections vary. • Intertrigo and toe web infection are examples
  • 9. Skin infections caused by S. aureus I. Direct infection of skin and adjacent tissues a. b. c. d. e. f. Impetigo Ecthyma Folliculitis Furunculosis Carbuncle Sycosis barbae II.Cutaneous disease due to effect of bacterial toxin a. b. Staphylococcal scalded skin syndrome Toxic shock syndrome
  • 10. Skin infections caused by group A ßhemolytic streptococci I. Direct infection of skin or subcutaneous tissue a. b. c. d. e. Impetigo (non bullous) Ecthyma Erysipelas Cellulitis Necrotizing fascitis II. Secondary infection Eczema infection
  • 11. Skin and Soft Tissue Infections 1. Impetigo: Initially a vesicular infection that rapidly evolves into pustules that rupture, with dried discharge forming honey-colored crust on an erythematous base. 2. Ecthyma (Pustules): Begin as vesicles that rupture, creating circular erythematous lesions with adherent crusts. 3. Folliculitis: Inflammation at the opening of the hair follicle that causes erythematouspapules and pustules surrounding individual hairs.
  • 12. 4. Furuncle: Deep-seated inflammatory nodule with a pustular center that develops around a hair follicle. (painful, localized, abscess). 5. Carbuncle: Involvement of several adjacent follicles, with pus discharging from multiple follicular orifices. 6. Cutaneous abscesses: Painful, fluctuant, red, tender swelling, on which may rest a pustule. 7. Erysipelas: Erythema and swelling of the cutaneous surface, involves the superficial dermis
  • 13. 8. Cellulitis: Erythematous, hot, swollen skin with irregular edge (affects the deeper dermis and subcutaneous fat). 9. Acne: Infection of sebaceous follicles with plugs of keratin blocking the sebaceous canal, resulting in “blackheads”. 10. Necrotizing fasciitis: Rapidly spreading cellulitis with necrosis (skin and deeper fascia; may involve muscle). Begin with fever, systemic toxicity, severe pain in the development of a painful, red swelling that rapidly progress to necrosis of the subcutaneous tissue and overlying skin.
  • 14. Impetigo and Ecthyma • Impetigo is a superficial skin infection with crusting (non bullous) or bullae (bullous) caused by streptococci, staphylococci, or both. • Ecthyma is an ulcerative form of impetigo. Crusted erosions on the arm of a child. The confluence of lesions in the antecubital fossa suggests prior atopic dermatitis at the site that became secondarily infected
  • 16. IMPETIGO (bullous) A large, single bulla with surrounding erythema and edema on the thumb of a child; the bulla has ruptured only in the center and clear serum exudes from it.
  • 17. Impetigo (Non-Bullous) Non-bullous impetigo is a superficial skin infection that manifests as clusters of vesicles or pustules that rupture and develop a honey-colored crust. Impetigo (Bullous) Bullous impetigo is a superficial skin infection that manifests as clusters of vesicles or pustules that enlarge rapidly to form bullae. The bullae burst and expose larger bases, which become covered with honey-colored varnish or crust.
  • 18. Ecthyma is a skin infection similar to impetigo, but more deeply invasive. Usually caused by a streptococcus infection, ecthyma goes through the outer layer (epidermis) to the deeper layer (dermis) of skin, possibly causing scars. Ecthyma gangrenosum is a bacterial skin infection (caused by Pseudomonas aeruginosa) that usually occurs in immunocompromised individuals
  • 19. Folliculitis • Folliculitis is a bacterial infection of hair follicles. • It is usually caused by Staphylococcus aureus but occasionally Pseudomonas aeruginosa (hot-tub folliculitis) • The bacteria is commonly found in contaminated whirlpools, hot tubs or physiotherapy pools • Children tend to get hot tub folliculitis more • Hot-tub folliculitis occurs because of inadequate treatment of water with chlorine or bromine.
  • 21. FOLLICULITIS Folliculitis manifests as superficial pustules or inflammatory nodules surrounding hair follicles. Superficial erythematous papules & crusts of hair follicles in the beard area , aggravated by shaving.
  • 22. Furuncles and Carbuncles • Furuncles are skin abscesses caused by staphylococcal infection, which involve a hair follicle and surrounding tissue. • Carbuncles are clusters of furuncles connected subcutaneously, causing deeper suppuration and scarring. They are smaller and more superficial than subcutaneous abscesses
  • 24. Furuncles (boils) are tender nodules or pustules caused by staphylococcal infection. Carbuncles are clusters of furuncles that are subcutaneously connected.
  • 25. CARBUNCLE Staph aureus - Large, inflammatory plaque studded with multiple pustules, some have ruptured, draining pus, on the nape of the neck. This very painful area is surrounded by erythema and edema, extends down to fascia, formed from a confluence of many furuncles.
  • 27. Cellulitis • Cellulitis is an acute bacterial infection of the skin and subcutaneous tissue most often caused by streptococci or staphylococci. • Some people are at risk for infection by other types of bacteria. They include people with weak immune system, and those who handle fish, meat, poultry, or soil without using gloves. • Cellulitis can occur anywhere on the body. In adults, it often occurs on the legs, face, or arms. In children, it is most common on the face or around the anus. An infection on the face could lead to a dangerous eye infection.
  • 28. CELLULITIS Portal of entry of infection is seen on the lateral thigh with necrosis of skin; infection has extended mainly proximally from this site.
  • 29. Erysipelas • Erysipelas is a type of superficial cellulitis with dermal lymphatic involvement. • It is characterized clinically by shiny, raised, indurated and tender plaque-like lesions with distinct margins (you can see a clear border between normal and infected skin). • Erysipelas is most often caused by group A β-hemolytic streptococci and occurs most frequently on the legs and face. • Other causes : Staphylococcus aureus (including MRSA), Klebsiella pneumoniae, H.influenzae, E. coli). • It is commonly accompanied by high fever, chills, and malaise. Erysipelas may be recurrent and may result in chronic lymphedema.
  • 31. Cutaneous Abscess • A cutaneous abscess is a localized collection of pus in the skin and may occur on any skin surface.
  • 32. Necrotizing Subcutaneous Infection (Necrotizing Fasciitis) • Typically caused by a mixture of aerobic & anaerobic organisms that cause necrosis of subcutaneous tissue, usually including 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. Diagnosis is by history and examination. • Treatment involves: antibiotics,surgical debridement, Amputation if necessary • Prognosis is poor without early, aggressive treatment.
  • 33. Necrotizing Fasciitis “Flesh Eating Strep” Streptococcus pyogenes (Group A β hemolytic Streptococci (GABHS) is the causative agent • Necrotizing fasciitis: The disease starts as localized infection that rapidly spreading cellulitis with necrosis (skin and deeper fascia; may involve muscle). • Begin with fever, systemic toxicity and severe pain • The development of a painful, red swelling that rapidly progress to necrosis of the subcutaneous tissue and overlying skin. • The Invasive & spreading cellulitis may lead to loss of limb • May lead to toxic shock
  • 35. Acne
  • 36. Acne • Most common skin disease in humans • Propionibacterium acnes: Gram +ve rod ,causative agent • Pathogenesis: bacteria digest sebum , Attracts neutrophils - Neutrophil digestive enzymes cause lesions, “pus pockets” • Obstruction of sebaceous follicles (oil glands) • Open comedones or closed comedones • Usually on the face, chest, back • Risk factors: – Stressful events (hormonal changes) – Friction acne – Oil based cosmetics – NO correlation between chocolate, chips or colas (No effects of diet)
  • 37. Acne Treatments • Tx: topical +/or oral antibiotics. • Benzoyl peroxide dries plugged follicles, kills microbes • Tetracycline (antibiotic) • Accutane – inhibits sebum formation
  • 38. HIDRADENITIS SUPPURATIVA  Hidradenitis suppurativa is a chronic, suppurative recurring inflammatory disease of apocrine gland follicles.  Commoner in females specially after puppetry.  Sites: axillae, around the nipples, under the breast, perineum, groin, buttocks, n eck and scalp.  lesions: nodules, abcesses, scarring,sinus tract formation.
  • 40. Erythrasma • Erythrasma is a bacterial skin infection that occurs in areas where skin touches skin, like between toes, in armpits, or groin • This intertriginous infection is caused by Corynebacterium minutissimum. • Most common among patients with diabetes. • Erythrasma is sometimes mistaken with fungal infections. • If you have such picture that’s not responding to anti-fungal therapy, see your doctor because erythrasma is easily treated with the proper antibiotics
  • 41. MRSA skin infections • • • • • • • • • • Methicillin-resistant Staphylococcus aureus “super-bug” – caused by staph, antibiotics abuse Outwits all but the most powerful of drugs – vancomycin Enters through cuts & wounds Types: CA (community acquired) or HA (Hospital acquired) S/S: small red bumps that resemble pimples, quickly turn to painful abscesses that can burrow deep into the body, swelling, redness, pus Risk Factors: recent hospitalization, long-term care, recent antiobiotic use, young age, contact sports, sharing towels, weak immune system, living in groups, health-care workers Dx: Tissue sample – 48hrs Tx: trial & error with strong antiobiotics Prevention: WASH HANDS, surfaces, cover wounds, use only personal items
  • 43. Recurrent skin infections • Recurrent skin infections should raise suspicion of colonization – Staphylococcal nasal carriage – Resistant strains of bacteria (eg. MRSA), – Cancer – Poorly controlled diabetes – Other reasons for immuno-suppression (eg, HIV, hepatitis, advanced age,….).
  • 44. Staph. carriage elimination • Nasal & perineal care • Rifampicin 600 mg/d 7-10 days • Clindamycin 150 mg/d 3 months • Topical mupirocin • Replacement of microflora with a less pathogenic strains of S.aurus (strain 502)
  • 45. Staphylococcal Scalded Skin Syndrome(SSSS) Mechanism: Exfoliatins • SSSS also called Lyell's disease or toxic epidermal necrolysis, starts as a localized lesion, followed by widespread erythema and exfoliation of the skin. • This disorder is caused by staphylococcal strain which elaboratse an epidermolytic toxin. The disease is more common in infants than in adults
  • 46. Toxic Shock Syndrome Mechanism: TSST-1 Localized growth of toxigenic strains in vagina or wound. - Starts abruptly with fever, hypotension, and diffuse macular erythematous rash. Multiple organs & systems are involved, entire body skin desquamates.
  • 47. Laboratory Diagnosis of Bacterial Infections of Skin (1) Specimen collection: 1. 2. 3. 4. Skin biopsy Skin swab Pus swab Nasal swab N.B. When pustules or vesicles are present, the roof or crust is removed with a sterile surgical blade. Pus or exudate is spread as thinly as possible on a clear glass slide for Gram staining
  • 48. Laboratory Diagnosis of Bacterial Infections of Skin (2) Suspected organisms • Impetigo: Group A Streptococcus, Staphylococcus aureus • Folliculitis: Staphylococcus aureus, Pseudomonas aeruginosa • Furuncles: Staphylococcus aureus • Carbuncles: Staphylococcus aureus • Cellulitis: Group A Streptococcus, Staphylococcus aureus, Hemophilus influenzae • Erysipelas: Group A Streptococcus • Necrotizing fasciitis: Group A Streptococcus, Clostridium perfringens and other species, Bacteroides fragilis, the anaerobes, Enterobacteriaceae, Pseudomonas aeruginosa
  • 49. Laboratory Diagnosis of Bacterial Infections of Skin (3) 1. Clinical specimen: Scrape the base of the skin lesion with a swab. Gram stain: Gram (+) cocci in clusters (or in chains) 2. Culture: Blood Agar (for both), Mannitol Salt Agar (for staph) Identification: catalase , Coagulase , mannitol fermentation On blood agar : both S. aureus & strept pyogens produces beta hemolysis. Tube Coagulase test Catalasa test
  • 50. Laboratory Diagnosis of Bacterial Infections of Skin (4) 2. Mannitol salts agar (MSA):high salt(7.5) inhibits the grow of most other organisms, S. aureus ferments mannitol, the acid produced turns the colonies yellow.
  • 51. Principles of therapy of pyoderma • Good personal hygiene • Management of predisposing factors • Aluminum chloride, a drying agent, inhibits overgrowth of opportunistic bacteria in foot, perineal, and axillary areas. • Keratinolytic agents (e.g., topical salicylates) remove hyperkeratotic lesions that harbor pathogens, improving the exposure of the infected skin surface to other topical treatments Systemic • Treatment of disease like DM • Nutritional deficiency • Immunodeficiency
  • 52. Principles of therapy of pyoderma • Local therapy – Cleaning with soap-water and weak KMN04 solution – Removal of crusts with KMN04 solution – Application of antibacterial creams or ointments • Systemic therapy – Antibiotics
  • 53. Topical Treatment • Topical antibiotics contain a combination of: neomycin, bacitracin, and polymyxin. • Some newer preparations contain: mupirocin, gramicidin, or erythromycin, and others combine these antibiotics with steroids. Systemic Therapy • Systemic treatment with antibiotics is mandatory for extensive pyoderma. • Systemic antibiotics can be administered orally or parenterally. Oral therapy is sufficient for most extensive dermal infections, but the parenteral route is preferred for severe infections.
  • 54. CHRONIC BACTERIAL SKIN INFECTION • Tuberculosis: caused by mycobacterium tuberculosis • Etiology: • Primary inf. : acquiring the bacilli for the 1st time • Post primary inf. occurs in pt with previous TB or previous BCG vaccination. • A- Localized: as lupus vulgaris, scrofuloderma and TB verrucosa cutis. • B- General: as miliary lesions, in pt with miliary TB & immune suppressed, multiple TB abscesses • C- Tuberculide 1. papulonecrotic tuberculide. 2. Lichen scrofulosorm. 3. Erythema induratum.
  • 55. • primary TB infection [tuberculous chancre] • Lupus vulgaris Scrofuloderm
  • 56. • Tuberculous warts: [tuberculosis verrucosa cutis] • Orificial TB • Papulonecrotic tuberculide Lichen scrofulosorum Erythema induratum
  • 57. Lupus vulgaris • • • • • Commonest 1ry infection Good natural immunity Heamatogenous spread Apple jelly nodule--scar Tuberculoid granuloma Mx: bx, AFB Local ttt Anti TB
  • 58. Diagnosis of skin TB • confirmed either by find the microorganism in culture media (never to be seen in skin lesion) • PCR • Presence of acid fast bacilli (by ZN stain) • History, positive tuberculin test, presence of caseating granuloma on histopathology and therapeutic response to anti-TB drugs