integumentary Flashcards
skin functions
- first line of defense against infection
- protect underlying tissues
- receives stimuli for touch, pressure, pain, + temperature for nervous system
- regulates body temp
- excretes salts, water, organic wastes
- protects from excessive water loss
- synthesizes vitamin D3 (converts calcitriol for normal calcium metabolism)
- stores nutrients
skin layers
- epidermis
- dermis
- hypodermis (subcautaneous fat)
epidermal appendages
- nails
- hair
- glands (sebaceous + sweat)
normal bacterial flora
- gram-positive + gram-negative staphylococci
- pseudominas
- streptococcus
pH of 4.3-5.6 halts bacteria growth
3 phases
wound healing phases
- inflammatory: begins at time of injury, lasts 3-5 days (local edema, pain, redness, itchiness, warmth, possible exudate)
- fibroblastic: 4th day to 2-4 weeks (scar tissue + granulation tissue forms)
- maturation: 3 weeks after injury for up to a year (scar tissue is thin, firm, inelastic)
1st to 3rd intention
healing by attention
1st intention: approximate wound edges are held in place (sutures) until healing occurs, wound easily closes
2nd intention: injuries or wounds with tissue loss + gradual filling of dead space with connective tissue loss
3rd intention: delayed primary closues, occurs with wounds that are left open for irrigation or debris removal
diagnostic tests
- skin biopsy
- skin/wound cultures
- Wood’s light (UV test) - for superficial skin infections
- diascopy - for lesion inspection
what it is + signs
candida albicans
aka yeast infection or thrush
superficial fungal infection of the skin + muscous membranes
risk factors: immunosuppression, long-term antibiotic therapy, medications, diabetes mellitus, obesity
signs
- skin: red/irritated, itches, stings
- mouth: red + whiteish patches
shingles
aka herpes zoster
caused by reactivation of the varicella-zoster virus with history of chicken pox
- dormant virus is in dorsal nerve root ganglia of sensory cranial + spinal nerves
- may have postherpetic neuralgia when lesions resolve
- contagious to individuals who never had chicken pox + are not vaccinated
signs:
- unilaterally clustered vesicles
- fever, malaise
- burning + pain
- paresthesia
- pruritis
methicillin-resistant staphylococcus aureus
- skin/wound becomes infected with MRSA
- community acquired (skin-to-skin contact, equipment sharing) or hospital acquired
- can present as folliculitis (follicule infection from staphylococcus), raised red rash + pustules
- or furuncles (deep in follicle)
- if MRSA infects the blood sepsis, organ damage, + death can occur
- contagious (spread by direct skin contact)
erysipelas + cellulitis
- erysipelas: acute/superficial infection affecting upper layers of skin from group A streptococcus from wound
- cellulitis: infection of dermis + hypodermis from streptococcus or staphylococcus aureus
- signs: pain, erythema, warmth, edema, fever
skin cancer types
basal cell: from epidermis, metastasis rare
squamous cell: tumor of epidermal keratinocytes, can infultrate surrounding structures + metastasize to lymph nodes
melanoma: mostly appear where birthmarks or new moles are apparent, highly metastatic to the brain, lungs, bone, + liver
signs: change in color/size/shape of preexisting lesion, pruritus, local soreness
psoriasis
chronic, non-infetious skin inflammations involving keratin synthesis
stevens-johnson syndrome
medication-induced reaction (antibiotics, antiseizure meds, NSAIDS)
diffuse erythema + blister formation on skin + muscous membranes, severe reactions involve respiratory system, renal system, eyes, can be fatal
more common in patients with impaired immune systems
what it is + meds
dermatitis
superficial inflammatory process involving the epidermis
meds:
* topical immunosuppressants (tacrolimus + pimecrolimus creams) - side effects include redness, burning, itching, sunlight sensitvity
* systemic immunosuppressants (methotrexate, oral glucocorticoids)
