7/29/2019 1) Bacterial Skin Inf
1/32
Bact skin inf
7/29/2019 1) Bacterial Skin Inf
2/32
Bacterial skin inf
Bacterial skin inf is the single most
common diagnosis among those with skin
problems.
The most common bacterial skin inf is
impetigo (superficial pyoderma)
7/29/2019 1) Bacterial Skin Inf
3/32
Group A beta hemolytic streptococcus
commonest cause of skin inf
Colonization of unbroken skin by GABS
precedes pyoderma by 10 days
Intradermal inoculation by insect bite,
scabies or minor trauma leads to
impetigo, ecthyma &cellulitis
7/29/2019 1) Bacterial Skin Inf
4/32
Cutan bact inf
Colonization or pyoderma may predispose
the child to later pharyngeal colonization
with the same strain
Staph aureus spread from the nose to
normal skin and then infect the skin
Clinically the 2 lesions cannot be
distinguished
7/29/2019 1) Bacterial Skin Inf
5/32
S.Pyogenes
Noninvasive strains Invasive trainss
impetigo pharyngitis
nephritogenic
Pyrogenic exotoxins proteinase Spreading factors
Rheumatogenic strain
Rheumatic feverpsgn
Scarlet fever
Toxic shock syndrome
Necrotizing cellulitis/fascitisCellulitis
erysipelas
7/29/2019 1) Bacterial Skin Inf
6/32
Bact skin inf
Those with recurrent inf should be
evaluated for immunodef (neutrophil
dysfunction)
7/29/2019 1) Bacterial Skin Inf
7/32
Impetigo: bullous
non bullous
Non bullous accts for >70% of the cases Tiny vesicle or pustule forms and rapidly
develops into a honey colored crusted
plaque Inf spreads by towels, fingers, clothings
7/29/2019 1) Bacterial Skin Inf
8/32
Contact sports
7/29/2019 1) Bacterial Skin Inf
9/32
7/29/2019 1) Bacterial Skin Inf
10/32
Little or no pain, no erythema, no
constitutional symptoms
7/29/2019 1) Bacterial Skin Inf
11/32
Bullous impetigo: infants and youngchildren
Caused by coagulase-positive staph
aureus Flaccid transparent bullae develop on the
skin of face, buttocks, trunk, perineum, &
extremities. Neonatal bullous impetigo can begin in the
diaper area
7/29/2019 1) Bacterial Skin Inf
12/32
Culture of fluid from an intact blister should
yield the causative lesion.
Complications are potential but rare: OM
septic arthritis,pneumonia &septicemia
7/29/2019 1) Bacterial Skin Inf
13/32
Deeper soft tissue inf may occur.
Erysipelas is an acute well demarcated inf
of the skin with lymphagitis involving the
face (ass with pharyngitis) &extremities
(wounds).
The skin is erythematous &indurated
The advancing borders are raised& firm
Ass with fever, vomiting& irritability
7/29/2019 1) Bacterial Skin Inf
14/32
Bact skin inf
CELLULITIS
Strept cellulitis is a painful, erythematous,indurated inf of the skin and subcut tissue
usually follows some injury to the skin
Proteinase producing strain causes amore severe type of necrotizing fascitis or
myositis Also more common in diabetics &
immunocompr
7/29/2019 1) Bacterial Skin Inf
15/32
Bact skin inf
Organisms : St.Pyogenes &S.aureus.
many other org can cause
Presents as local edema, warmtherythema &tenderness.the margins are
indistinct
Regional adenopathy,constitutional S/Sfever, chills &malaise
7/29/2019 1) Bacterial Skin Inf
16/32
Bact skin inf
Complications : OM, sep arthritis,
bacteremia, necrotizing fasciitis
Treatment :specific antibiotics,after proper
evaluation , cultures from the site
In a newborn a full septicemic work up
Cover for strep and staph
7/29/2019 1) Bacterial Skin Inf
17/32
Necrotising Fasciitis (Meleneys
streptococcal gang, Fourniers Is a destructive invasive infection of skin,
subcutaneous tissue &deep fascia with relativesparing of muscle.
Bacteriology could be polymicrobial or
monomicrobial due to group A Beta HaemolyticStrep.
Common sites are genetalia, groin & lowerabdomen.
Pts are unwell, febrilewith areas ofsubcutaneous induration & erythema.Necroticpatches of skin develop.
7/29/2019 1) Bacterial Skin Inf
18/32
Bact skin inf
Treatment is by wide excision of alleffected soft tissue, anibiotics andsupportive treatment. Wide skin deffectswill need surgical procedures to repairthem.
Mortality is high and increases if surgicalexcision is delayed.
Risk factors are D.M., malnutrition,obesity,steroids & immune defecieny.
7/29/2019 1) Bacterial Skin Inf
19/32
Vaginitis :beta hemolytic strep. Are a
common cause of vaginitis in prepubertal
girls.pts usually have a serous discharge&
marked erythema & irritation of the vulvararea,discomfort in walking &urination
7/29/2019 1) Bacterial Skin Inf
20/32
Perianal dis: perianal strep cellulitis
produces local itching,pain,blood streaked
stools, erythema & proctitis.
7/29/2019 1) Bacterial Skin Inf
21/32
Bact skin inf
Staph scalded skin syndrome (Ritter dis)
Agent :staph aureus phage grp 2 str.71,55
Predominantly in infants& children
7/29/2019 1) Bacterial Skin Inf
22/32
Bact skin inf
The scarlatiniform erythema developsdiffusely & is accentuated in flexural &periorificial areas
Conjuntivas : inflammed, discharge maybe purulent
Skin is brightly erythematous& rapidly
wrinkled Severe cases- sterile flaccid blisters &
erosions develop diffusely
7/29/2019 1) Bacterial Skin Inf
23/32
Bact skin inf
Nikolsky sign may be positive(areas of
epidermis separate in response to gentle
shear force
As large sheets of epidermis peel
away,moist glistening denuded areas may
get sec infected ,fluid &electrolyte
imbalances
Healing without scarring in 10 14 days
7/29/2019 1) Bacterial Skin Inf
24/32
Bact skin inf
Antibiotics :orally or parenterally withsemisynthetic penicillinase- res penicillin
Gently moisten the skin and cleanse with
Burow or Dakin soln or N saline Emolient application for lubrication to
decrease discomfort
Recovery is rapid Complications-Pneum,sept,cellulitis,fluid&
electrolyte imbalincreased morbidity
7/29/2019 1) Bacterial Skin Inf
25/32
Bact skin inf
Ecthyma :resembles non bullous impetigoin onset and appearance
Gradually deeper,into the dermis, more
chronic inf and forms an ulcer withelevated margins
Ulcer becomes obscure by a dry heaped
up crust that contributes to the persistenceof inf and scar formation
Spread :autoinoculation
7/29/2019 1) Bacterial Skin Inf
26/32
Lesions may be as large as 4 cm
Frequently on legs
Predisposing factors :as impetigo Causative agent: GABHS (staph is
cultured sec pathogen)
Crust softened by warm compressions &removed by antibact soap
Syst antibiotic tt as in impetigo
7/29/2019 1) Bacterial Skin Inf
27/32
Bact skin inf
Blastomycosislike pyoderma
Exuberant cutaneous reaction to bact inf in
children who r malnourished and
immunosupp
Organism: GABHS,staph aureus
7/29/2019 1) Bacterial Skin Inf
28/32
Various clinical presentations of
Staph. Skin infections.
Boil (fruncle)- is an infection of hair root
including sebaceous gland which usually
proceeds to suppuration and central necrosis.
Boils are common on face, neck and head. Boilsare infrequently associated with overwork, worry,
debelity or may be presenting feature of D.M.
Stye is due to infection of an eyelash follicle, if
suppuration occurs removal of eyelash will allow
drainage.
7/29/2019 1) Bacterial Skin Inf
29/32
Various clinical presentations of
Staph. Skin infections.(ct)
Carbuncle- is an infective gangrene ofsubcutaneous tissue which usually occurs in thenape of neck.
The subcutaneous tissue becomes painful andindurated, overlying skin is red. Unless thecondition is aborted by prompt treatmentextension occurs and after few days areas ofsoftening appear, skin sloughs out anddischarges pus. Usually there is one largecentral slough and surrounded by a rosette ofsmaller area of necrosis. Treatment is as for boil.
7/29/2019 1) Bacterial Skin Inf
30/32
Lupus vulgaris (T.B. of skin)
Occurs between the age of 10-25 face being thesite of election.
One or more cutaneous nodules appear withcogestion of surrounding skin. Extension occurs
very slowly but ulceration is likely to followsooner or later.The resulting ulcer heals in onearea as it expands to another. The mucousmembrane of mouth and nose could be attackedprimarily or as extension from face.
Treatment is by ATT, lesion can be excised ifhealing is slow.
Squamous cell carcinoma tend to occur in scars.
7/29/2019 1) Bacterial Skin Inf
31/32
Lupus vulgaris
7/29/2019 1) Bacterial Skin Inf
32/32
Advance Lupus vilgaris
Top Related