HLTH 2501: skin infections Flashcards
what can skin infections be caused by?
bacteria, viruses, fungi, or other types of microorganisms including parasites
primary bacterial infections
are caused by resident flora
secondary bacterial infections
develop in wounds or pruritic lesions
what can deeper bacterial infections cause?
the formation of a mass of pus in the tissue which is referred to as an abscess
what does pus consist of?
living and dead WBCs and bacteria, along with tissue debris and serum
what is acne?
a staphylococcal infection
cellulitis
is an infection of the dermis and subcutaneous tissue, usually resulting secondary to an injury, a furuncle (boil) or an ulcer
what is the causative organism of cellulitis?
S aureus or streptococcus
where does cellulitis typically occur?
in the lower trunk and legs
who does cellulitis typically develop in?
those with restricted circulation or immunocompromised
signs of cellulitis
reddened area, edema, pain, and red streaks running along the lymph vessels
how is cellulitis treated?
antibiotics and analgesics for pain
furuncle
is a boil that is an infection that begins in a hair follicle and spreads into the surronding dermis
what are furuncles caused by?
S aureus
common locations for furuncles
face, neck, and back
signs of furuncles
firm, red lesion, painful nodule which develops into a abscess, and large amounts of purulent exudate
what can squeezing boils result in?
the spread of infection by autoinoculation
autoinculation
the transfer of microbes from one site of infection to another site, most likely by fingers
furuncles in the nasal area
can lead to thrombi or infection that spreads to the brain
carbuncles
are a collection of furuncles that coalesce to form a large, infected mass, which may drain through several sinuses or develop into a single large abscess
treatment for furuncles
warm compresses will promote drainage, analgesics for pain, and it can also be cut and drained
impetigo
is a bacterial infection common in children and very contagious
what causes impetigo?
S aureus but also by group A beta-hemolytic streptococci
signs of impetigo
small, red vesicle lesions on the face, yellowish-brown crusty masses formed by rupture of the vesicles, and pruritus which may spread the infection
treatment for impetigo
topical antibiotics
acute necrotizing fasciitis
‘flesh eating disease’ because the bacteria rapidly invades tissues and causes reduced blood supply to the tissues, as well as the secretion of protease enzymes that destroy tissues
what microorganism causes acute necrotizing fasciitis?
gram-positive, group A, beta-hemolytic streptococcus pyogenes (same bacteria responsible for strep throat)
what infection can toxic shock occur in?
acute necrotizing fasciitis
signs of acute necrotizing fasciitis
infected area appears inflamed and is very painful, infected area grows in size, dermal gangrene is apparent, and systemic toxicity causes fever, tachycardia, hypotension, mental confusion and disorientation, and possible organ failure
what are the signs of acute necrotizing fasciitis similar to?
cellulitis
treatment for acute necrotizing fasciitis
antimicrobial therapy, fluid replacement, excision of infected tissue, high O2 flow in hyperbaric chambers, and possibly amputation
leprosy microorganism
mycobacterium leprae
prevalence of leprosy
not as common today but still exists in Africa Asia, the South Pacific and some areas of South America
how is leprosy transmitted?
extended contact with a source
why is leprosy hard to study?
because the organism cannot easily be grown in a culture media