Dermatology Flashcards
flat spot less than 1cm (non-palpable, just visible)
ex:freckles, tattoos
macule
flat spot>1cm
ex:port wine stain
patch
solid, elevated lesion
papule
same as papule but >!cm and flat-topped
ex: psoriasis
plaque
palpable, solid lesion >1cm, not flat-topped
ex: small lipoma
erythema nodosum
nodule
elevated circumscribed lesion
vesicle
same as vesicle but >5mm (large blister)
ex. contact dermatitis, pemphigus
bulla
Itchy, transiently edematous area
ex:allergic reaction
wheal
erysipelas
upper dermis
superficial lymphatics
may appear raised with clear line of demarcation
cellulitis
deeper dermis
subcutaneous fat
risk factors for erysipelas and cellulitis
chronic skin problems diabetes mellitus chronic swelling of LE IV drug use immunocompromiased state penetration of skin (surgery/trauma) previous cellulitis
Diagnosis and labs in cellulitis and erysipelas
Clinical diagnosis
increased WBC count, ESR, CRP
blood cx
Common organisms in cellulitis
- beta- hemolytic strep
s. pyogenes, group B strep - s. aureus common in abscesses
How do we treat cellulitis
non-purulent cellulitis:
PO- dicloxacillin
cephalexin
clindamycin
IV- cefazolin
nafcillin
clindamycin
purulent cellulitis: PO- clindamycin TMP-SMX Doxycycline Linezolid
IV abx-
vancomycin
Skin abscesses
collection of pus within dermis and deeper skin tissues
Furuncle (boil):
infection of hair follicle
purulent material extends through dermis into subQ tissue
often drains spontaneously
Carbuncle
coalescence of several inflamed follicles
Diagnosis of abcess, furuncle, carbuncle
clinical
culture is indicated for bacterial idenfication
-s.aureus in 75% of cases
Treatment of skin abscess
let the pus out
if large,
incision and drainage
for patients at risk of endocarditis: vancomycin 1hr prior to incision and drainage
oral: clindamycin, tmp-smx, doxycycline, linezolid
IV: vancomycin
antibiotics are often unsuccessful because you need to get the pus out
Hidradenitis suppurative
recurrent infection/occlusion of apocrine glands
MC site: axilla
Tx:
-general measures: avoid skin trauma, gentle cleansing, smoking cessation, weight loss
-mild disease: topical clindamycin daily, punch debridement
second line: clindamycin with rifampin
severe disease: oral doxycycline or minocycline, more invasive surgical debridement
-alternative treatments: intralesional steroids, anti-adrenergic drugs, TNFa inhibitors, oral retinoids
necrotizing fasciitis
infection spreading along fascial plane
polymicrobial- anaerobes, gram +, gram -
GAS
often in the setting of some systemic disease
H and P:
unexplained, excrutiating pain in the absence of or beyond areas of cellulitis
bulla, necrosis, crepitus
Dx: surgical exploration is the only way to definitively diagnose, as well as to treat
rapidly worsening cellulitis with severe pain
Xray: crepitus, subcutaneous air can be seen with plain film on an xray
Fournier gangrene
perineal cellulitis with abrupt onset and rapid spread
this is a urological emergency
What is the general treatment for necrotizing fasciitis?
immediate aggressive surgical debridement
abx:
1. carbapenem (imipenem or meropenem)
or beta-lactam plus beta-lactamase inhibitor (piperacillin +tazobactam)
PLUS
2. clindamycin
PLUS
3. vancomycin
Gangrene
significant amounts of body tissue necrosis
a chronic condition compared with necrotizing fasciitis
dry gangrene (chronic, distal, severe ischemia) treat with revascularization or allow auto-amputation
wet gangrene: bacterial infection in moist tissue: debridement, possible amputation
gas gangrene: caused by clostridium perfringens
- debridement
- hyperbaric oxygen
- antibiotics
Impetigo
contagios skin infection among young children
s. aureus is MCC (MSSA)
s. pyogenes
vesicles that form and rupture to form thick crust, most commonly on the face
Treatment:
mild- mupirocin
moderate-severe: dicloxacillin, cephalexin
MRSA: clindamycin, TMP-SMX, doxycycline
Acne vulgaris
- hyperkeratosis
- retinoic acid (tretinoin)
- isotretinoin is PO, potent - sebum overproduction
- isotretinoin
- tretinoin
- spironolactone (anti-androgen, decreases testosterone and cortisol)
- OCP - propionibacterium acnes proliferation
- erythromyicin PO
- tertracycline PO
- doxycycline PO
- minocycline PO
- clindamycin PO
- topical clindamycin
- benzoyl peroxide - inflammation
- steroids
affecting areas that have hormonally- sensitive sebaceous glands
isotretinoin side effects
hepatotoxicity teratogenic drying and cracking of skin and lips depression elevated TG
Acne drugs that can cause photosensitivity
tetracycline
doxycycline
tretinoin
Rosacea
cause is not understood
inflammation, UV damage, vascular damage
middle- aged patient
facial erythema with telangiectasias starting at nose and cheeks
recurrent facial flushing provoked by various stimuli including hot/spicy foods, alcohol, temperature extremes, emotional reactions
no comedones, but otherwise looks a little like acne
ocular blepharitis, conjunctivitis, keratitis
bumpy nose (sebaceous gland hyperplasia)- rhinophyma
Topical treatment:
- metronidazole
- azeleic acid
Systemic treatment:
- tetracycline, doxycycline, minocycline
- isotretinoin for severe refractory cases
- laser therapy for rhinophyma
HSV
recurrent viral infection of mucocutaneous surfaces
HSV1- oral disease
viral genetic disease in sensory areas
cold sores every month, every 5 years
small painful vesicles around the mouth, lasting several days
eyes, esophagus
Herpetic whitlow- cutical, painful
Dx:
Tzanck smear on a q-tip
viral culture
serology
Tx: treats symptoms, can’t be cured
acyclovir
famciclovir
valacyclovir
contagious even when you don’t see lesions
Vertical transmission can cause disseminated disease
Newborns can get herpes temporal lobe encephalitis
Varicella
primary disease- chickenpox
secondary- shingles
clinical features:
prodrome of malaise, fever, pharyngitis, HA, myalgia for 24 hours prior to rash onset
pruritic evolving rash with teardrop vesicles, crusting over
face, trunk, extremities, spreads over 2-4 days, crusted over by 6 days
superinfection may occur (s. pyogenes)
adults may develop PNA or encephalitis
Treatments for children with chickenpox?
antihistamines for pruritis
cut fingernails closely to avoid excoriations leading to bacterial superinfections
acetaminophen for fever
no need for acyclovir in otherwise healthy children younger than 12
acyclovir if:
- > 12yo
- hx of chronic cutaneous or cardiopulmonary disorders
- taking intermittent oral or inhaled steroids
- chronic salicylates
prevention:
varicella vaccina now given at 1 year and 4 years old
Shingles
reactivation of herpes zoster virus
painful, grouped vesicles in a dermatomal distribution
postherpetic neuralgia possible
transmission through direct contact with active lesion (not as transmissible as chickenpox)
treatment: antivirals if presenting within 72 hours -valacyclovir -famciclovir -acyclovir: high dosing frequency but low cost
Analgesia with opioids
Corticosteroids (prednisone tapered over 7 days) only if severe symptoms and no contraindications. Usually the high risk of side effects outweighs the only modest benefits.
ppx: shingles vaccine for everyone over 50 year
do not give to pregnant women, or immunocompromised
Treat postherpetic neuralgia
months, years, fades over time
gabapentin pregabalin TCAs lidocaine patches capsaicin cream
Acne treatment
benzoyl peroxide topical retinoid or antibiotic oral antibiotic OCPs spironolactone isotretinoin
Rosacea treatment
topical metronidazole or azeleic acid
laser therapy
systemic treatment:
- tetracycline
- doxycycline
- minocycline
- isotretinoin
Warts
benign epithelial growths caused by HPV 1-4 (skin)
Genital warts HPV 6 and 11
Treatment options for cutaneous warts:
- 2/3 resolve spontaneously within 2 years
- salicylic acid (first line)
- liquid nitrogen
- 5-FU and imiquimod
- curettage, trichloroacetic acid, cantharidin (blister juice from beetles), surgical excision
Molluscum contagiosum
seem most commonly in children
adults with HIV, perineal region
tinea versicolor
- malassezia furfur
- hypopigmented or light brown or pink macules often found on back and shoulders
- hyphae and spores (spaghetti and meatballs) seen microscopically
will scale when scraped
Treatment: ketoconazole 2% shampoo topical antifungal (terbinafine) selenium sulfide PO antifungal for extensive disease (ketoconazole, fluconazole, itraconazole) dandruff shampoo can also be affective
Tinea
capitis (scalp) corporis (body) cruris (groin) pedis (foot) unguium (nails)
caused by microsporum, trichophyton, epidermophyton
pruritic, erythematous, blisters, scaly plaques, central clearing
diagnose with KOH, hyphae present
Treatment:
SKIN- topical (clotrimazole, terbinafine, nystatin)
PO- (terbinafine, itraconazole, fluconazole)
Scalp: PO (griseofulvin, terbinafine, itraconazole, fluconazole)
Nails: PO (terbinafine, itraconazole, fluconazole); topical (cilcopirox, efinaconazole)
check LFT before starting these meds
Intertrigo
candida albicans
looks like diaper rash
common in skin creases
irritant dermatitis by contrast, won’t have satellite lesions, and won’t be as much in the folds
KOH shows pseudohyphae
Treat with topical clotrimazole or terbinafine
Scabies
RF: crowded living conditions
poor hygiene
Severe pruritis with burrows and papules located on extremities and between fingers and toes
Skin scrapings will show mites and eggs under microscope
treat with permethrin cream
diphenhydramine and corticosteroids help with itching
wash everything in hot water
infection of close contacts is a common complication
lice and crabs
diagnosis by direct visualization
all cause pruritis
Pediculosis capitis:
- treat with permethrin cream or shampoo, rinse after 10 minutes, then comb out lice and nits
- alternatives: topical malathion or ivermectin
Pediculosis corporis: body louse
-treat with permethrin cream and leave on for 8-10 hours
Pediculosis pubis: groin lice
- Treat with permethrin or pyrethrin cream and rinse out after 10 minutes, and then comb
- Alternatives: topical malathion and ivermectin
- sexually transmitted
Hypersensitivity reactions in the skin (mainly 1 and 4)
Type 1: mast cell degranulation: IgE, immediate allergy
Type 4: delayed type, cell-mediated immune memory response
Morbilliform rash days after 2nd exposure to allergen
Common causes: plants, nickel, soaps, latex
Stop offending agent remove contact with allergen topical steroids oral antihistamines oral corticosteroids IM epinephrine
Erythema multiforme
erythema multiforme: deposition of immune complexes into superficial microvasculature and mucous membranes
often a drug reaction (PCN, sulfonamides, NSAIDs, PO contraceptives, anticonvulsant medications)
HSV and mycoplasma pneumoniae are common infectious causes that can lead to erythema multiforme
Appearance: skin lesion, target, pale zone, darker outer ring
can be anywhere
lesions develop over 10+ days:
macule> papule> vesicles/bullae in the center of the papule
common sites:
hands/forearms, sole/feet, elbows and knees, penis and vulva
Severe form (EM major) always involves the mucuous membranes and can become SJS/TEN
Treatment for erythema multiforme
stop inciting medication
symptomatic treatment with antipruritics
if severe- systemic glucocorticoids (although no proven effectiveness)
if patient also has history of HSV, then antiviral such as acyclovir or valacyclovir
SJS and TEN
SJS is severe EM, always involves mucous membranes
skin sloughs,
TEN
> 30% of BSA
full-thickness epidermal necrosis
treat in a burn unit
IV fluids
Labs:
decreased H/H
increased ALT, AST
IV hydration
acyclovir
Seborrheic dermatitis
chronic relapsing dematitis a/w sebacious glands
possible cause is malassezia furfur
erythematous plaques with greasy- looking, yellowish scales
Treatment:
scalp: medicated shampoo (ketoconazole, selenium sulfide, ciclopirox); alternative is tar- containing shampoo
skin: low-potency topical steroids or topical antifungal cream (ketoconazole)
What diseases are a/w increased incidence of seborrheic dermatitis?
Parkinson, HIV, psoriasis, immunocompromised patients (transplant patients)
Exacerbations are common in emotional stress and hospitalizations
Severe intractable seborrheic dermatitis may point to HIV infection
Seborrheic keratosis
various presentations, variable size, pasted on
no treatment needed
dark
warty
Actinic keratosis
precancerous lesion a/w sun exposure
Atopic dermatitis
oozing, crusty
often found in children
asthma allergies
dry vesicles
treatments:
skin hydration: emollients
topical steroids
calcineurin inhibitors: tacrolimus or pimecrolimus
severe or resistant cases: UV light therapy, systemic steroids, immunosuppressants (methotrexate, cyclosporine, azathioprine)
antibiotics for open lesions (cover s.aureus and streptococcus)
side effects a/w calcineurin treatment
lymphoma
keep duration short
psoriasis
immune- mediated
red plaques on knees and elbows
pustules
silvery scales
clinical diagnosis
skin biopsy: thickened epidermis
absent granular layer
nucleated cells in stratum corneum
are you having joint pain as well? check for arthritis
psoriasis treatment
mild to mod disease:
- topical steroids and emollients
- alternatives: tar-nased products, topical retinoids (tazarotene); topical vitamin D (calcipotriene), anthralin, calcineurin inhibitors (tacrolimus, pimecrolimus)
Severe disease:
- phototherapy
- oral retinoids
- immunosuppressants (methotrexate, cyclosporine)
- adalimumab, etanercept and infliximab
Pityriasis rosea
benign, self- limited inflammatory disease, in children or young adults with possible viral association, seen on trunk
herald patch: 2-5 cm, precedes christmas tree, pink, confirm lack of hyphae with KOH prep
clinical diagnosis
Treatment: self- limiting moderate-potency topical steroid for pruritis severe disease: UV therapy acyclovir erythromycin
Erythema nodosum: cause
SPUD BITS
shins, trunk, etc
delayed immunologic reaction to drugs, infection, IBD
Streptococcal infection Pregnancy Unknown (idiopathic) Drugs Behcet disease Inflammatory bowel disease Tuberculosis Sarcoidosis
H and P: malaise arthralgia tender erythematous nodules (pretibial) fever
Labs:
possible +ASO
increased ESR
Bx: fatty infiltration
Treatment: self- limited NSAIDs potassium iodid corticosteroids
Lichen planus
pruritic
purple
polygonal plaque, shiny and flat, commonly on the flexor surface (wrist, etc)
Wickham’s striae is a white, lace-like pattern on the surface of the papules/plaques
Mucous membrane involvement: Wickham’s striae in the lateral buccal mucosa and possibly erosive lesions that may become infected with Candida
Genital involvement: usually limited to violaceous papules on the glans penis in men, vulva of women
RF:
HIV
Hep C
Treatment:
corticosteroids of medium to high potency (topical or intralesional, oral if topical is unsuccessful)
acitretin (oral retinoid)
Decubitus ulcers
stage 1: pressure-related, change in color, skin intact
stage 2: superficial ulcer
stage 3: full thickness with damaged tissue
stage 4: full thickness with damage to muscle, etc
Treatment: good nutrition and hydration remove pressure on ulcer debridement wound care antibiotics
Stasis dermatitis
RF: chronic venous insufficiency. LE
eczematous, inflammatory papules, increased pigmentation, stippling, old hemorrhages
clinical diagnosis
venous reflux is confirmed using duplex ultrasound
Treatment for stasis dermatitis
weightloss compressive dressings of stocking leg elevation topical steroids vein ablation
Medications most commonly associated with erythema multiforme
penicillins sulfonamides OCPs NSAIDs anticonvulsants
EM vs. SJS vs. TEN
EM:
milder disease
no sloughing of skin
SJS:
skin-sloughing limited to 30% of BSA
Psoriasis- what does it look like?
red plaques with silvery scales
extensor surfaces
Auspitz sign
classic presentation of erythema nodosum
pretibial nodules within subcutaneous fat
-painful and erythematous
classic presentation of pityriasis rosea
herald patch, followed by rash in Christmas tree patten
no treatment needed
classic presentation of lichen planus
pruritic, purple, polygonal, plaques and papules on flexor surfaces of extremities
Pemphigus vulgaris
flaccis, easy to rupture blisters, +Nikolsky
almost always with oral lesions
antibodies in epidermis
anti-desmosome antibody
Tx: high dose systemic steroids, azathioprine or mycophenolate mofetil (steroid-reducing adjuvant)
antibiotics for 2ndary infection
fatal without treatment
Bullous pemphigoid
tense bullae
rare oral lesions (10-30%)
antibodies found at dermal- epidermal junction
antihemidesmosomes, with better prognosis than pemphigus
topical steroids (clobetasol)
PO steroids (prednisone) if topical steroids aren’t possible
chronic management: mycophenolate mofetil
azathioprine
methotrexate
Porphyria cutanea tarda
deficiency in uroporphynogen decarboxylase
porphyrin accumulates
acute porphyria
-nervous system:neuropathy, abd pain, mental disturbances
cutaneous porphyria:
-excess porphyrins near the surface of the skin
risk factors: hepatitis C, alcohol abuse, excess iron
classic presentation: blistering lesions
chronic skin thickening on sun-exposed areas, hyperpigmentation, calcification, facial hypertrichosis
diagnosis:
elevated urinary porphybilinogen
diagnosis: elevated plasma porphyrins
treatment:
phlebotomy
hydroxychloroquine
avoidance of sun, alcohol, estrogens, iron supplements
Actinic keratosis
precancerous skin lesion
RF: sun exposure
erythematous papule with rough, yellow-brown scales
biopsy: dysplasia
Treatment: topical 5-FU, imiquimod, cryotherapy
0.1%/year risk of squamous cell carcinoma
Squamous cell carcinoma
skin cancer of squamous cells of epithelium
RF:sun exposure, arsenic exposure, fair complexion, radiation- especially UVB
painless, well-demarcated, scaly patch or plaque, erythematous, scaling
Treatment: surgical excision (Mohs), radiation
5-10% metastesize
Basal cell carcinoma
mc skin cancer
least likely to metastesize
pearly papule
rolled edges
treatment: surgical excision (Mohs), radiation, cryotherapy
Melanoma
malignant melanocyte tumor
RF: sun exposure, fair complexion, family history, numerous nevi
Types:
-superficial spreading is most common, grows laterally before vertically (back on men, legs on women)
-nodular: only grows vertically and becomes invasive rapidly
-acral lentiginous: least common, found on palms, soles, and nail beds
lentigo maligna: slow growth, 10-50 years before vertical growth
Labs: excisional biopsy shows atypical melanocytes and possible invasion into the dermis (>.76 mm is associated with increased risk of metastasis)
Treatment:
0.5 cm margin if in situ
1cm margin if 2mm thick +/- lymph node dissection
chemotherapy and radiation if metastasis
Most commonly mets to brain, lung, GI tract
periodic skin checks if history of sun exposure or family history of melanoma
ABCDE of melanoma
Asymmetry Border irregularity Color Diameter >6mm Evolving
Do not shave; excisional biopsy
Most important prognostic indicator in melanoma
depth of lesion
BCC appearance
pearly papule
telangiectasias
rolled edges if ulcerated
Squamous cell carcinoma appearance
papule or ulcer
scaling or keratinization
irregular or disorderly appearance
either painless or painful
split-thickness graft
graft composed of epidermis and part of the dermis
abdomen, thighs, buttocks
extensive, large surface areas
full-thickness graft
face and hand defects
composite graft
fat, nailbed, etc, site-speficit reconstructions are the indication
fasciocutaneous flap
skin+subQ tissue+vascular supply
donor sites: forehead, groin, deltopectoral region, thighs
indicated for large defects
muscle flap
may include skin (myocutaneous)
donors: TFL, gluteal muscle, lat
indications- deep tissue injury, radiation injury
Melasma
dark skin discolration common in pregnant women and those taking OCPs or hormone replacement therapy
Tx by minimizing sunlight exposure and sunscreen
titanium and zinc oxide
Triple combo cream: tretinoin, hydroquinone, mid-potency topical steroid (flucinolone)
What are characteristic features of vitiligo
sharply demarcated patches of complete depigmentation (due to loss of melanocytes)
- borders are hyperpigmented
- more common at acral areas and around body orifices
Skin is of normal texture (excludes morphea and lichen sclerosis)
Associated with thyroid disease in 30% of patients (especially women)
mo
most common age 20-30
Autoimmune disorders associated with vitiligo
GRaves autoimmune thyroiditis pernicious anemia type I DM primary adrenal insufficiency hypopituitarism alopecia areata autoimmune hepatitis
Treatment for vitiligo
sunscreen to minimize tanning of normal skin, which would increase the contrast
dyes and make-up to camofluage depigmented area
topical corticosteroids (first line)
Tacrolimus or pimecrolimus (calcineurin inhibitors)
Psoralens (topical or oral) + UV light (PUVA or UVB) for extensive disease
surgical mini-grafting is an option when medical therapy fails
hydroquinone for depigmentation of normal skin to match regions of vitiligo (ast resort)
Acanthosis nigricans
velvety hyperpigmentation
most commonly seen on lateral folds of axilla, neck, groin
associated with hyperinsulinemia and visceral maligancies
Treat underlying disorder:
diabetes
weightloss
discontinuation of medication (glucocorticoids, OCPs), or treatment of malignancy
Tretinoin (topical)
Calcipotriene (Vit D topical analog)
blue mass that does not regress
cavernous hemangioma (venous malformation)
Treatment for infantile hemangioma
uncomplicated infantile hemangiomas will gradually resolve within the frist 2 years of life, therefore observation is usually the best treatment
Complicated infantile hemangiomas: oral propanolol, systemic glucocorticoids, vincristine, interferon alpha
Clinical features of alopecia areata
asymptomatic, inflammatory, non-scarring areas of complete hair loss
may be precipitated by stress
regrowth after 1st affack in 30% by 6 months, in 50% by 1 year, in 80% by 5 years
10-30% will not regrow hair
5% progress to total hair loss
obtain syphilis screen CBC BMP ESR TSH ANA (to rule out pernicious anemia, chronic active hepatitis, thyroid disease, SLE, Addison)
Rule out trichotillomania (pulling out one’s hair): look for broken hair shafts of different lengths, consider shaving a small patch oand observe over a few weeks for growth
Treatment: intralesional steroid injection topical corticosteroids minoxidil topical topical immunotherapy anthralin cream (children) oral steroids
What name is given to diffuse stress-related hair loss?
What is the treatment?
Telogen effluvium
self- limited
reassurance, stress relief
androgenic alopecia
causes are both hormonal and genetic
dihydrotestosterone causes follicular miniturization leading to replacement of terminal hairs by short, thin hairs
inheritance involves both paternal and maternal factors
Treatment:
Finasteride (5alpha-reductase inhibitor)
Minoxidil (topical)
Caused by complete lack of melanocytes
vitiligo
Hair loss associated with effects of dihydrotestosterone on hair follicles
androgenic alopecia
Most common co-morbidity in vitiligo
TSH
purple-red lesion on face that does not regress with age
port wine stain
infant with bright red lesion that regresses over months-years
strawberry hemangioma
benign, small papule that appears on skin with age
cherry hemangioma
bright red papule with radiating blanching vessls
spider angioma
blue, compressible mass that does not regress
cavernous hamengioma
red-pink nodule on a child that is often confused with melanoma
Spitz nevus
anti-centromere abs
CREST scleroderma
