Dermatology Flashcards
Cellulitis
Acute bacterial skin infection from portal entry
MCC - GA Strep or S. aureus; animal bites via P. multicida or human bites E. corrodens
Sxs:
- Pain, warmth, swelling
- Spreading erythema (mark w/ pen) - non blanching
- flat margins and NOT well demarcated
Dx:
would culture f/u in 48 hrs
Tx:
- Mild cellulitis - MSSA
- Cephalexin or Dicloxacillin
- Cat bite - Augmentin or doxy if PCN allergic
- Puncture wound - Cipro
- MRSA
- Bactrim 1 DS tab PO BID
- Clindamycin 300-450 mg PO
- Doxycyclin 100 mg PO BID
Burns - Degrees and Rule of 9s
Rule of 9s (pic)
1st degree - sunburn
- erythema involved tissue
- skin blanches w/ pressure
- skin may be tender
2nd degree - partial thickness
- skin is red and blistered
- skin very tender
3rd degree - full thickness
- burned skin is tough and leathery
- skin non-tender
4th degree - Into bones and muscles
Burns - minor/major, tx
Minor
- < 10TBSA adults
- < 5 TBSA young/old
- <2% full thickness
- not involve face, hands, perineum, feet, cross major joints or be circumferential
Major
- > 25% TBSA adults
- >20% TBSA young/old
- >10% full thickness burn
- Burns w/ face, hands, perineum, feet, cross major joints/circumferential
Tx:
- monitor ABCs, fluid repletion, topic abx
- cleans w/ mild soap and water, no direct ice
- Irrigate chemical burns w/ running water x 20 ms
- topic abx for superficial burns
- fingers and toes wrapped individually to prevent maceration and gauze placed btwn them
Pressure Sores
Sacrum and hip most often affected; resposition every 2 hrs
Stage 1 - erythema of localized area, usu non-blanching over bony surfaces
- Aggressive preventative measures, thin-film dressings for protection
Stage 2 - partial loss of dermal layer, resulting in pink ulceration
- Occlusive dressing to maintain healing
- transparent films, hydrocolloids
Stage 3 - full dermal loss often exposing subcutaneous tissues and fat
Stage 4 - full thickness ulceration exposing bone, tendon, or muscle. Osteomyelitis might be present
Treatment:
- debridement of necrotic tissue
- Exudative ulcers - will benefit from absorptive dressings - calcium alginates, foams, hydrofibers
- Dry Ulcers - occlusive dressing to maintain moisture, hydrocolloids, hydrogels
Basal Cell Carcinoma
Cancer that begins in basal cells
Basal cells produce new skin cells - increased cell turnover.
Prevent via limiting skin exposures
Sxs:
- white waxy lump or brown scaly patch
- raised pearly and rolled borders
- telangiectasis
- Central ulcer on sun exposed areas - face and neck
Dx - shave or punch biopsy
Tx
- dependent on size and location
- Surgical - long term f/u
- Fluorouracil to affected area (Efudex)
- Imiquimod (Aldara)
- Photodynamic tx, tissue scraping, MOHS sx, wide local excision
Melanoma
eti, sxs
Tumor from melanocytes - most from skin but can also be primary lesion from ocular, GI, GU, LN
MC sites - back for men, calves for women; MCC in women 25-29yo, 2nd to Breast cancer in W 30-34yo; easily mets
Sxs:
- Asymmetry
- Border - irregular
- Color - varied
- D - diameter - increasing or > 6 mm
- Elevation - raised
Melanoma
dx, tx
HARMM - important risk factors for increasing risk of melanoma
- Hx of prior melanoma
- > 50yo
- Abs of reg derm
- changing mole
- Male
Dx - biopsy - full depth of dermis + slightly beyond lesion edge
Clark system for microstaging
Tx:
- a/w depth
- within epidermis = good prognosis
- incr thickness = bad prognosis = upper back, upper arm, neck or scalp
- Excision and wide margins
- Stages I-III => surgical excision is curative
- Stage IV => systemic chemo
- Prevent sunburns
- use at least SPF 30
Drug Eruption (Postoperative)
Drug exanthems - MCC cutaneous rx
- MCC abx, sulfonamides
Sxs
- rash
Dx
- Clinical and skin biopsy
- Histological = sloughed skin w/ necrotic epithelium
- Ddx is erythema multiforme, viral exanthems, other drug rashes
Tx
- stop all offending meds
- admit to burn unit for initial stabilization and mgmt of fluid, electrolytes and nutrition.
- Prompt ophtal and derm
- IVIG
- Steroids incr risk of sepsis
Squamous cell Carcinoma
Malignant epithelial tumor from epidermal keratinocytes
Sxs:
- enlarging hyperkeratotic macule, scaly or crusted lumps
- arise w/in pre-existing actinic keratosis or intraepidermal carcinoma
- Erythematous, indurated, scaly papules
- on skin exposed areas in elderly
- Grow faster than BCC - over wks and months
- Tender and painful
Dx - biopsy
Tx
- surgical excision w/ +/- Mohs
- Radiotherapy
- cryotherapy
- Electrodessication
- Good prognosis = negative margins, small lesions. 10% Mets
Urticaria (postoperative)
Pruritis and urticaria freq occurs during preanesthesia period
Etis:
- Undesired effect of anesthetic age
- widespread use of potent opioids = intrathecal and epidural
- Latex, abx, LMWH
- Cold compresses
- underlying systemic dease
