Pathology 5: Bacterial Skin Infections

Many skin disorders are what?

contagious

most are localized, but some ave systemic consequences

What are the 3 classifications of bacterial infections?

1. primary

2. secondary

3. systemic

What are primary bacterial infections?

occur on normal skin

What are secondary bacterial infections?

complicate preexisting skin diseases, wounds or ulcers

What are systemic bacterial infections?

skin is involved in systemic blood borne infections, leading to sepsis

What is sepsis?

life-threatening organ dysfunction caused by a dysregulated host response to infection

What are factors that predispose factors to skin infections?

dec resistance

dehydrated skin

burns or ulcers

DEC BLOOD FLOW

contamination from nasal discharge

poor hygiene

crowded living conditions

What are pyodermas?

primary bacterial skin infections typically caused by pus forming bacteria (staph or strep)

What are common pyodermas?

impetigo

ecthyma

cellulitis

erysipelas

folliculitis

furuncle

carbuncle

What is impacted in pyodermas?

infection may be limited to epidermis or involve the hair follicle and dermis

What is impetigo?

superficial skin infection caused by staph or strep commonly found in infants, young children and older people

What are predisposing impetigo?

close contact, crowded living conditions, poor skin hygiene, anemia

What are s+s of impetigo?

itching, erythema, pain, adenitis (inflammation of gland)

What are the types of impetigo?

bullous and non-bullous

What is bullous impetigo?

large fragile blister looking lesions

What are CIs for impetigo?

massage is postponed until areas have healed completely

What is the cause of bullous impetigo?

staph

Who is most impacted by bullous impetigo?

children (on face) and older people

What does bullous impetigo affect?

completely intact skin

epidermis separates from the dermis and collects fluid between the two laters

What does bullous impetigo leave behind when healed

crusted region

How is bullous impetigo spread?

direct contact, environmental contamination, autoinoculation

What is autoinoculation?

organism is transferred to another site on the body

What is the treatment for bullous and non-bullous impetigo?

good hygiene and topical or oral antibiotics

What is more common: bullous or non-bullous impetigo?

non-bullous

1% of pediatric population in most countries

How does non-bullous impetigo begin?

reddened area with blisters, then develops pustules which rupture and form and area of honey-coloured crusts

What is the cause of non-bullous impetigo?

strep

What does non-bullous impetigo impact?

skin that has been damaged, ie from excoriation, burns or other infections

Who is impacted by non-bullous impetigo?

children in their face, arms and other exposed areas

How is non-bullous impetigo spread?

very contagious

spread by direct contact and crowded living

What is ecthyma?

deep impetigo that affects the dermis due to group A step

What are s+s of ecthyma?

lesions form a bullae which then forms an ulcer (impetigo does not form an ulcer)

very painful and create a scar

regional lymphadenopathy common

What can ecthyma stem from?

untreated impetigo

What is the treatment for ecthyma?

antibiotics

keeping area clean

What is cellulitis?

inflammation of skin and subQ layer

What is the incidence of cellulitis?

common

What is the cause of cellulitis?

staph or strep

What are risk factors for cellulitis?

skin breaks (visible or microscopic) and immunosuppressant

What are local s+s of cellulitis?

pain, swelling, tenderness, erythema, warmth

ulcers and pustules

mm and fascia are spared

What are systemic s+s of cellulitis?

fever, chills

What is the treatment for cellulitis?

antibiotics

What can untreated cellulitis lead to?

sepsis

abscess formation

destruction of tissue

lymphangitis

What are massage considerations for cellulitis?

local CI in localized cases

absolute CI in widespread cases

What is erysipelas?

looks similar to cellulitis but margins of inflammation are clearly raised with clear borders to the infection

What causes erysipelas?

Strep pyogenes

What are s+s of erysipelas?

inflamed area if red, warm, painful

lymphangitis

malaise, chills, fevers

Where is erysipelas most common?

over the face, can occur over the legs

How can erysipelas be treated?

antibiotics, cool compresses

What can erysipelas lead to?

permanent skin discolouration post-treatment

What is folliculitis?

inflammation of hair follicle, resulting in inflammatory cell migration and formation of pustule

What is the cause of folliculitis?

staph

rarely fungal or other bacteria

can be d/t trauma to follicle or idiopathic

Where does folliculitis occur?

face, scalp, thighs, axilla, inguinal

What is a stye?

folliculitis of the eyelid

What is the treatment for folliculitis?

good handwashing and course topical antibiotics

What are furuncles?

boil, skin absscess

tender dome shaped lesion

What are the causes of furuncles?

infection around a hair follicle with staph A

What are s+s of furuncles?

painful and hard

large abscess develops at a site of folliculitis

What are carbuncles?

many furuncles grouped together

Where are carbuncles most common?

moist parts of the body because bacteria thrives

What may carbuncles be a sign of?

DM

What can carbuncles cause?

permanent skin scarring

What is the treatment for carbuncles?

antibacterial soap, antibiotics

What is hidradenitis suppurativa (HS)?

disorder of the follicular epithelium in the apocrine gland, where the duct becomes blocked and inflamed

What is the cause of hidradenitis suppurativa (HS)?

idiopathic

can be hormones, genetics, smoking, obesity

What is the most common location for hidradenitis suppurativa (HS)?

axilla and groin

What are characteristics of hidradenitis suppurativa (HS)?

-pustules and nodules (large, painful)

-scarring

-primarily an inflammatory disorder which can be complicated by bacterial infection

What is the treatment for hidradenitis suppurativa (HS)?

good hygiene is key

anti-inflammatory medication

antibiotics