Integumentary Disorders Flashcards
What is cellulitis?
A bacterial infection with associated inflm in the deeper dermis & subcutaneous layer
Which 2 bacteria are usually responsible for cellulitis?
- β hemolytic strep
- Staph aureus
Where in the body can staphylococcus aureus be found?
Present in small numbers on the skin & in the nasal passages of some individuals
What are 2 risks for cellulitis? Why?
- Existing dermal lesions (e.g.ulcers) pose a risk as they allow microbe entry
- Elderly & immunocompromised persons are at higher risk
Which areas are most affected by cellulitis
Affected areas are mostly the legs, hand & ears
Why do microbes spreads easily through the subcutaneous layer?
Due to loosely packed tissue
In cellulitis, is subsequent lymphatic entry also possible?
Yes
T or F:
Cellulitis is not a recurrent infct
F, recurrence is a major problem, especially for those at higher risk
Mnfts of cellulitis:
4
- Painful lesions at the affected site
- Erythema
- Edema
- Fever
Complications of cellulitis:
4
- Sepsis
- Gangrene
- Lymphangitis (inflm of lymphatic vessels)
- Abscesses
What is the Tx of cellulitis?
Abx!
- PO for mild cases, IV for severe
What is Psoriasis?
A complex, chronic, inflm skin disorder characterized by an abnormal rate of epidermal cell turn over with stacking of cells on the skin surface due to non-shedding of cells
What are the peak ages of onset for psoriasis?
2
- 16-22
- 57-60
What is the Et of psoriasis?
largely idiopathic with genetic predisposition (~30%) & an autoimmune basis
What is psoriasis believed to be initiated by?
Skin trauma
How do T cells contribute to psoriasis?
- Altered T cell response to an unknown Ag, suggested to lead to an accelerated epidermal cell cycle
- Mediators from activated T cells cause abnormal growth of keratinocytes & blood vessels
What is the length of a normal cell cycle? How does this change with psoriasis? What does this result in?
- Normal cycle length is ~1 m, in psoriasis it is 3-4 days
- Cells are improperly differentiated and instead of shedding, they stack on the surface of the skin forming scaly patches
What is hyperkeratosis?
Describes how the epidermis thickens in affected areas
What is psoriasis exacerbated by?
4
- Stress
- Trauma
- Infect
- Drugs
What is the koebner phenomenon
Areas of the skin previously unaffected with psoriatic lesions present with isomorphic (similar in appearance) lesions following trauma to the site
What are some mnfts for psoriasis?
- Psoriatic patches appear in varying locations
- Often knees, elbows, sacral region, and scalp
- ~30-50% of patients present with nail dystrophy & pitting due to abnormal amount of keratin
- In later stages of disease, psoriatic arthritis develops in distal joint
What topical treatments are used for psoriasis? Explain why.
- Salicylic acid
- Softens & removes lesions
- Coal tar
- Unknown action
- Anthralin
- Modulates keratinocytes & T cells
- Steroids
- Anti-inflammatory, immunomodulary
- Retinoids
- Anti-inflm & regulation of T cells?
What drugs are used to treat psoriasis? Explain why.
- Methotrexate
- Immunomodulatory drug that inhibits the
action of folic acid, which is involved in DNA
replication and cell division, results in decreased
turnover of keratinocytes and T cells
- Immunomodulatory drug that inhibits the
- Cyclosporine
- Immunosuppressive
- Biologic agents
- e.g. TNF is a cytokine that causes tumor regression
and apoptosis; its action here is unclear
- e.g. TNF is a cytokine that causes tumor regression
- Phototherapy
- Ultraviolet B decreases rate of cell proliferation
