Dermatology -Jones Flashcards
Erysipelas effects which layers of the skin?
Upper dermis and superficial lymphatics
Cellulitis effects which layers of the skin?
Deeper dermis and subcutaneous fat
Abscesses effect which layers of the skin?
Upper and deeper dermis
Which skin/soft tissue infection is observed in middle-aged and older adults?
Cellulitis
Which microbe commonly causes erysipelas?
Beta-hemolytic streptococci
Which microbe commonly causes cellulitis?
Beta-hemolytic strep and staphylococcus aureus including MRSA
Which microbe commonly causes a skin abscess?
Staph aureus
Acute onset of sx, clear demarcation-butterfly involvement of face are manifestations of what?
Erysipelas
Localized sx developing over days, indolent course with less distinct borders is what?
Cellulitis
Cellulitis can present with or without
Purulence (pus)
Erysipelas is what
Nonpurulent (no pus)
A skin abscess is a collection of
Pus within the dermis of subq space
Furuncle
Skin abscess can develop via infection of hair follicle
Carbuncle
Multiple hair follicle infection-leading to skin abscess
Regional adenopathy and surrounding induration happen with what?
Skin abscess
Diagnosis of erysipelas
Raised above level of surrounding skin, clear demarcations
LRINEC Score
Laboratory Risk Indicator for Necrotizing Fasciitis
A LRINEC score above what can rule in NF
6
Some complications of soft tissue infections include
NF, Bacteremia and sepsis, osteomyelitis, septic joint
What empiric therapy is used in a moderate purulent soft tissue infection? (Furuncle, carbuncle, abscess)
TMP/SMX (Bactrim) or Doxycycline
What empiric therapy can be used for a severe purulent soft tissue infection?
Vancomycin, daptomycin, linezolid, televancin, or ceftaroline
What is the proper treatment of a mild nonpurulent soft tissue infection? (Cellulitis, erysipelas)
Oral Rx! Like penicillin, cephalosporin, dicloxacillin, or clindamycin
What is the treatment for a moderate nonpurulent soft tissue infection?
IV Rx! Penicillin, Ceftriaxone, cefazolin, or clindamycin
How do you treat a severe nonpurulent soft tissue infection?
Surgical inspection/debriedment along with empiric Rx (Vanco plus piperacillin/tazobactam)
What is found most frequently in children ages 2-5?
Impetigo
What is primary impetigo?
Direct bacterial invasion of normal skin
What is secondary impetigo?
Infection is at the site of skin trauma
The most common form of impetigo
Non-bullous
Papules progress to vesicles surrounded by erythema in what?
Non-bullous impetigo
The papules in non-bullous impetigo form into what?
They breakdown and form thick golden crusts
Bullous impetigo
Vesicles enlarge to form flaccid bullae with clear fluid, leaves brown crust
What is ecthyma?
Ulcerative form of impetigo
“Punched-out” ulcers covered with yellow crusts are from what?
Ecthyma
What microbe causes impetigo?
Staph aureus, occasionally beta-hemolytic strep A
Microbe causing bullous impetigo
S.aureus strain that cleaves the superficial skin layer
Microbe causing ecthyma?
Group A beta-hemolytic strep pyogenes
What topical therapy is used for limited non-bullous and bullous impetigo?
Mupirocin and Retapamulin
What oral therapy is used for extensive impetigo and ecthyma?
Dicloxacillin and Cephalexin
What are hives, welts, and wheals?
Urticaria
Urticaria can also be accompanied by what?
Angioedema
What is the duration of acute urticaria?
Less than 6 weeks
Chronic urticaria
Recurrent, with signs an symptoms recurring most days of the week for more than 6 weeks
Round oval vary in size 1 cm up to several
Urticaria
The angioedema in urticaria effects what parts of the body?
Lips, extremities, genitals
What mediates the reaction in urticaria?
Cutaneous mast cells in the superficial dermis
What is released by cutaneous mast cells in urticaria?
Histamine (itching) and vasodilator mediators (swelling)
What are some medications used to treat urticaria?
H1 antihistamines (Diphenhydramine, chlopheniramine, hydroxyzine, cetirizine, loratadine, fexofenadine) H2 antihistamines (Ranitidine, nizatidine, all end in -tidine) Glucocorticoids (Prednisone)
A common benign soft-tissue neoplasm
Lipoma
What do lipomas consist of?
Mature fat cells, enclosed by a thin fibrous capsule
What is a benign soft tissue neoplasm that occurs mainly on the upper extremities and trunk?
Lipoma
A cutaneous cyst with a visible central punctum
Epidermal inclusion cyst
Skin colored dermal nodule
Epidermal inclusion cyst
Where are epidermal inclusion cysts commonly located
Face, scalp, neck, and trunk
What syndrome are epidermal inclusion cysts seen in?
Gardener Syndrome (hereditary condition)
Treatment of epidermal inclusion cyst?
Excision of cyst or incision and drainage
What’s the most common cutaneous disorder affecting adolescents and young adults
Acne
Acne is a disease of
Pilosebaceous follicles
What are the 4 factors of acne?
- Follicular hyperkeratinization
- Increased sebum production
- Cutibacterium acnes within the follicle
- Inflammation
What happens in prepuberty to the sebaceous glands?
They enlarge and sebum production increases
Sebum provides a growth medium for?
C.acnes
What provides an anaerobic lipid-rich environment for bacteria in acne?
Microcomedones
What is another name for a white-head?
Closed comedone
What is another name for a black-head?
Open comedone
What leads to inflammatory papules and nodules in acne?
Proinflammatory lipids and keratin
What can cause infantile acne?
Elevated levels of androgens produced by immature adrenal glands in girls and immature adrenal glands and testes in boys
What serum level rises as puberty approaches?
DHEA-S levels