Dermatology Flashcards
Age: 30-40s
bulllae - thin and fragile, painful NOT ITCHY
involves mouth
Nikolsky’s sign
Pemphigus Vulgaris
“so bad it’s vulgar”
Abs in Pemphigus Vulgaris
Abs against desmosomes (against Ags in the intercellular spaces of the epidermal cells)
In what conditions can you see Nikolsky’s sign
Pemphigus Vulgaris
Staphylococcal Scalded Skin Syndrome
Toxic Epidermal Necrolysis
Dx and Tx of Pemphigus Vulgaris
DX: bx of skin
TX: PO glucocorticosteroids
Age: 70-80s
bulllae - tense, thick (don’t rupture), painful, ITCHY
DOESN’T INVOLVE MOUTH
NO NIKOLSKY’S SIGN
Bullous Pemphigoid
Abs in Bullous Pemphigoid
Abs against hemidesmosomes (IgG and C3 deposits at dermal-epidermal junction)
Dx and Tx of Bullous Pemphigoid
DX: bx from edge of blister
TX: PO glucocorticosteroids
Non-healing PAINLESS blisters (increased fragility) on sun-exposed areas of the body (backs of hands and face)
Hyperpigmentation of skin
Hypertrichosis of face
Prophyria Cutanea Tarda
Def. in enzyme uroporphyrinogen decarboxylase = accumulation of porphyrins (in heme pathway)
What conditions are associated w/ Prophyria Cutanea Tarda
Hep C
OCPs
Alcoholism
Liver Disease
Dx and Tx of Prophyria Cutanea Tarda
DX: test for urinary uroporphyrins
TX:
- stop alcohol, estrogen use
- use sun protection
- use phlebotomy
- chloroquine to increase excretion of porphyrins
HSN Rxn Type I –> mediated by IgE and mast cell activation
wheals and hives
itching
Urticaria
Common causes of Urticaria
MDXs insect bites foods emotions contact w/ latex
Causes of Chronic urticaria:
- cold
- vibration
- pressure on skin (dermatographism)
Tx of Urticaria
Acute Therapy: H1 antihistamines (eg. diphenhydramine) PO steroids (if life threatening)
Chronic Therapy:
Non-sedating antihistamines (eg. loratadine)
Desensitization (if trigger can’t be avoided)
Milder version of urticaria
Generally due to MDXs the pt is allergic to
Maculopapular eruption that blanches w/ pressure
Morbiliform Rash
TX: antihistamines
Targetlike lesions that can be confluent
On palms and soles
NO mucous membrane involvement
Nonspecific prodrome: fever, malaise, sore throat
Erythema Multiforme
TX: antihistamines
Causes of Erythema Multiforme
Infxn w/ herpes simplex (MCC) or mycoplasma
Malignancy and collagen vascular disease
MDXs:
- PNC
- NSAIDs
- Sulfa drugs
- Phenytoin
- Allopurinol
Acute flu-like prodrome Rapid onset red macules, vesicles, bullae Mucous membrane involvement < 10-15% total body surface area Necrosis and sloughing of epidermis
Stevens-Johnson Syndrome
TX:
- admit to burn unit
- IVIG
Causes of Stevens-Johnson Syndrome
MDXs:
- PNC
- NSAIDs
- Sulfa drugs
- Phenytoin
- Allopurinol
- Phenobarbital
30-100% total body surface area
40-50% mortality rate
Nikolsky’s sign (skin sloughs off easily)
Toxic Epidermal Necrolysis
DX: skin bx
Causes: MDX (vs. Staphylococcal scalded skin syndrome caused by toxin from bacteria)
painful, red, raised nodules on anterior surface of shins
Erythema Nodosum
Causes of Erythema Nodosum
secondary to recent infxns (eg. strep) or inflammatory conditions including:
- pregnancy
- coccidioidomycosis
- histoplasmosis
- sarcoidosis (get CXR)
- UC
- syphilis
- hepatitis
Tx of Erythema Nodosum
Analgesics + NSAIDs
Tx underlying dx
scattered papules w/ some red, SCALY areas on scalp
PATCHY HAIR LOSS
lymphadenopathy and SCARRING
Tinea Capitis
DX: KOH prep of hair shaft
Tx of Tinea Capitis
PO antifungal
- -> griseofulvin
- -> terbinafine
- -> itraconazole
Prevent by not sharing hats/combs
Tx for nail fugal infxn
PO antifungal x 6 wks (fingernails) OR x 12 wks (toe nails)
- -> griseofulvin
- -> terbinafine
- -> itraconazole
on arms/legs
red, itchy, scaly, RING-SHAPED lesions w/ raised borders that CLEAR CENTRALLY while expanding peripherally
Tinea Corporis
Tx for Tinea Corporis
PO griseofulvin
fungal infxn of hands
seen in pts w/ pre-existing tinea pedis
red, itchy, scaly, cracking lesions
Tinea Manuum
Tx of Tinea Manuum
Topical antifungal (eg. miconazole)
HYPOPIGMENTED or light brown or pink macules often found on back, shoulders, or neck
Macules DON’T TAN (more apparent in summer/spring)
Tinea Versicolor (due to Malassezia furfur)
Dx and Tx of Tinea Versicolor
DX: see hyphae and spores (spaghetti and meatballs)
TX:
First line: ketoconazole 2% shampoo (selenium sulfide shampoo)
PO antifungal (if resistant to tx)
Tx Guidelines for Nail or Scalp Fungal Infxn
use PO antifungals:
- -> griseofulvin
- -> terbinafine (SE: hepatotoxic)
- -> itraconazole
Tx Guidelines for Fungal Infxn NOT involving hair or nail
use topical antifungals:
- -> terbinafine (SE: hepatotoxic)
- -> clotrimazole
- -> ketoconazole (SEs: hepatotoxic, gynecomastia)
- -> miconazole
- -> nystatin
Tx Guidelines for Bacterial Skin Infections (eg. impetigo, cellulitis, folliculitis)
use PO dicloxacillin or cephalexin
use IV oxacillin or nafcillin OR IV cefazolin
if suspecting MRSA use IV vanc (PO equivalent = clindamycin, linezolid, Bactrim, doxycycline)
weeping, crusting, oozing of skin
small, yellow (“honey colored”) pustules on face especially child
Non-Bullous Impetigo
Cause and Predisposing Factors to Non-Bullous Impetigo
CAUSE:
S. aureus or S. pyogenes (Grp A Strep)
Predisposing Factors:
pre-existing skin trauma (eg. insect bite)
atopic dermatitis (eczema)
Tx of Non-Bullous Impetigo
TOPICAL mupirocin
Severe disease = PO dicloxacillin or cephalexin
Cause and Sxs of Bullous Impetigo
CAUSE:
S. aureus ONLY
SXs:
Rapidly growing flaccid bullae w/ yellow fld
Tx of Bullous Impetigo
PO dicloxacillin or cephalexin
abrupt onset
skin (eg. face) is bright red, hot and raised w/ sharp borders
area is painful and hyperesthetic to touch
fever, chills, malaise (systemic sxs)
Erysipelas
Tx of Erysipelas
First Line: PO dicloxacillin or cephalexin Severe disease (w/ systemic sxs): IV oxacillin or nafcillin OR IV cefazolin
Complications of all skin infxns
Glomerulonephritis (NOT R. fever)
warm, red, swollen, tender skin
Cellulitis
RFs for Cellulitis
obesity
disruption of skin (eg. by tinea pedis –> tx foot fungus in pts w/ recurrent cellulitis)
Difference b/w Cellulitis or DVT
Cellulitis has ↑ WBCs and NO risks of hypecoagulability
Cause of Cellulitis
S. aureus and S. pyogenes
Tx of Cellulitis
First Line: PO dicloxacillin or cephalexin Severe disease (w/ systemic sxs): IV oxacillin or nafcillin OR IV cefazolin
Tx of Folliculitis
Topical mupirocin
Tx of Furuncles and Carbuncles
PO dicloxacillin or cephalexin
severe, life threatening infxn
cellulitis that dissects into the fascial planes of skin
very high fever
have hx of laceration, trauma, surgical procedure (portal of entry into skin)
pain out of proportion to superficial appearance
bullae
palpable crepitus (in C. perfringes infxn)
Necrotizing Fasciitis
MC organisms involved in Necrotizing Fasciitis
Streptococcus (Grp A Strep) and Clostridia
Dx of Necrotizing Fasciitis
↑ CPK
X-ray/CT/MRI –> shows air in tissue (black circles) or necrosis
Surgical debridement = BEST Dx and Tx
Tx of Necrotizing Fasciitis
Surgical debridement
Broad spectrum ABX until cx results come back
–> piperacillin/tazobactam + Vancomycin + Clindamycin
Mortality rate = 80%
Tx for Acute Herpes
PO acyclovir
Acyclovir - Resistant herpes = PO Foscarnet
Herpetic Whitlow
non-purulent vesicles on hands
Tx: self-limited
Ramsay Hunt Syndrome (herpes zoster oticus)
HERPES ZOSTER = SHINGLES = REACTIVATION OF VZV (VARICELLA = HHV 3)
ear manifestation of reactivated zoster virus:
- -> ear pain
- -> vesicles in external auditory canal
- -> I/L facial paralysis
Tx of Ramsay Hunt Syndrome (herpes zoster oticus)
IV acyclovir
Who gets Zoster (VZV) vaccine?
≥ 60 yoa (not for HIV pts w/ CD4 <200, pregnant pts, pts w/ immunodeficiency or on immunosuppressive therapy)
Who gets treated for Herpes Zoster/Varicella
Immunocompromised child OR primary infxn in adult
Tx for Herpes Zoster/Varicella if:
pt comes w/in 72 hrs of rash vs. pt comes > 72 hrs after rash
Within 72 hrs of rash –> PO acyclovir or PO valacyclovir (better than acyclovir) to PREVENT postherpetic neuralgia (NOT to prevent rash from spreading)
> 72 hrs after rash –> give pain MDX and zinc oxide cream
Acute Herpetic Neuralgia
persists ≤ 30 days from rash onset
Tx: NSAIDs, analgesics
Subacute Herpetic Neuralgia
persists > 30 days but resolves within 4 months of rash onset
Tx: NSAIDs, analgesics
Postherpetic Neuralgia
persists > 4mo from rash onset
Tx: Gabapentin, TCAs, pregabalin
Tx of Primary (chancre) and Secondary Syphilis
IM PCN (single dose)
cutaneous warts
–> hyperkeratotic papules on soles of foot
–> thickened, enlarging papule
infxn via skin to skin contact
Plantar Warts (from HPV)
Dx: scrapings of hyperkeratotic debris confirm dx
Tx of Plantar Warts
initial = salicyclic acid (takes 2-3 wks to notice change)
How is Scabies transmitted and Tx?
Person to person contact
Tx: 5% permethrin cream
- -> must tx all household contacts and bedding/clothes need to be washed
- -> if can’t use topical therapy (eg. in nursing home), then use PO ivermectin
Tx for Lice?
5% permethrin cream
Tx of Lyme rash
PO doxycycline or amoxocillin
Fever > 102F
SBP <90
desquamative rash (diffuse, red macular rash –> like sunburn)
vomiting
involvement of mucous membranes of eye, mouth, genitals
↑ Cr, CPK, LFTs, Bands
↓ PLT
Toxic Shock Syndrome
–> caused by staph via exotoxin (TSS toxin 1)
Tx for Toxic Shock Syndrome
vigorous fld resuscitation antistaph MDXs (eg. nafcilin)
superficial flaccid bullae, perioral crusting then subsequent scaling and desquamation
Nikolsky’s sign
NORMAL BP (unlike TSS)
NOT full thickness split (like TEN)
Staphylococcal Scalded Skin Syndrome
–> mediated by toxin from Staph
Tx of Staphylococcal Scalded Skin Syndrome
Manage in burn unit Antistaph ABXs (ABXs don't reverse disease but they kill Staph that is producing toxin)
papule appears then get central necrosis (black in color) surrounded by edematous ring –> “black eschar or black scab”
Anthrax
From Bacillus anthracis (in ppl with livestock contact)
TX: ciprofloxacin or doxycycline
Dx and Tx of Melanoma
DX: excisional bx
TX: excision w/ wide margins
Ocular Melanoma
primary malignant tumor arising from melanocytes w/in uvea
blurry vision, progressive and painless visual field abn
Dx of Ocular Melanoma
U/S of eye
MRI (for staging)
Tx of Ocular Melanoma
Asymptomatic pt w/ small lesions (diameter <10mm, thickness <3mm) –> observe w/o tx; repeat exam in 3 months and every 6 months thereafter
Symptomatic pt w/ large lesions (diameter ≥ 10mm, thickness ≥3mm) –> need radiotherapy
stuck on appearance of hyperpigmented lesions
Seborrheic Keratosis
–> assoc. w/ GI and lung tumors (explosive onset of multiple pruritic lesions –Lesar Trelat sign)
Precancerous lesions on sun-exposed areas in old ppl
rough, small, red papules w/ yellow/brown scales (“sandpaper like texture”)
Actinic Keratoses
- -> can regress and recur
- -> 20% risk of SCC
TX: sunscreen, 5-FU, cryotherapy
suspect in pt w/ chronic scar that develops into non-healing, painless, bleeding ULCER
on sun-exposed areas in old ppl
Squamous Cell CA
DX: Punch Bx
TX: Mohs surgery (if don’t want surgery = radiation)
–> metastatic D = chemo
Presents like SCC but comes and goes
flesh colored lesion w/ central crater that contains keratinous material
Keratocanthoma
Tx: goes away on it’s own (if not, resect)
shiny, pearly appearance w/ telengectasias and rolled edges
Basal Cell CA
DX: Punch Bx
TX: Mohs surgery
benign vascular skin tumor on lip/oral mucosa red, small papule that grows rapidly over wks or months and forms pedunculated or sessile shiny mass can occur after trauma bleeds w/ minor trauma common in pregnant pts
Pyogenic Granuloma
SCC in situ
Bowen’s Disease
purple lesions on skin (including genitalia, LE, face) in pts w/ HIV and CD4 <100
Kaposi’s Sarcoma
(HHV 8)
Tx: antiretroviral therapy
silvery scales on extensor surfaces that bleed when scraped off
nail pitting
Psoriasis (in adults)
Tx for Psoriasis
1) Emollients
2) Salicyclic acid to remove collections of scaly material so other therapies can work
3) Mild - Moderate Psoriasis –> localized, topical HIGH POTENCY steroids (0.05% fluocinonide)
4) Severe Plaque Psoriasis (>10% body involved) –> UV light, methotrexate
5) Extensive psoriatic arthritis and psoriasis involving nails –> methotrexate
Tx of Facial and Intertriginous Psoriasis
Topical tacrolimus
Topical, LOW POTENCY steroids (1% hydrocortisone)
What is Guttate Psoriasis? Tx?
red, scaly, small teardrop shaped spots
Tx: observation
red, itchy plaques of flexor surfaces (“itch that rashes”)
scaly rough areas of thickened skin
↑ IgE
Atopic Dermatitis (Eczema) –> onset before age 5
Allergic triad:
- asthma
- allergic rhinitis
- eczema
Complication of Eczema
superficial skin infxns due to scratching
Tx of Eczema
Prevent w/ emollients
Active Disease managed w/ topical steroids (eg. triamcinolone) OR antihistamines
Tacrolimus for areas where steroids CI (eg. face, eyelids, flexor surfaces)
umbilicated vesicles (superimposed on healing atopic dermatitis lesions)
fever
adenopathy
Eczema Herpeticum
–> form of primary HSV infxn (life threatening in infants)
TX: acyclovir
dermatitis that involves palms and soles
assoc w/ redness, itching, scaling
Dyshidrotic Eczema
very itchy patches of eczema on back and LEs
Nummular Eczema
Dandruff on face
scaly, greasy, flaky skin on red base found on scalp, eyebrows, nasolabial folds, chest, upper back, axilla, inguinal/pubic area
Seborrheic Dermatitis
Tx of Seborrheic Dermatitis
LOW POTENCY steroids (hydrocortisone) Topical antifungal (eg. selenium sulfide, ketoconazole)
Chronic relapsing condition (so need tx every 1-2 wks)
thickened, excoriated plaques caused by persistent scratching and rubbing
occurs in areas easy to reach (eg. arms, legs neck)
assoc w/ anxiety disorders
Lichen Simplex Chronicus
itchy eruption that begins w/ herald patch then disseminates
NO palms/ sole involvement
Pityriasis Rosea
TX: self limited
facial erythema w/ telengiectasias staring at nose and cheeks
recurrent facial flushing provoked by various stimuli including hot/spicy foods, alcohol, temp extremities, emotional rxns
inflammatory pustules
no comedones
ocular sxs (burning sensation, conjunctivitis, etc)
Rosacea
Tx of Rosacea
Topical metronidazole
PO doxycycline
Severe, refractory cases = isotretinoin
Rhinophyma = laser surgery
Tx of Comedonal Acne
topical retinoids +/- salicyclic glycolic acid
Tx of Inflammatory Acne
Mild: topical retinoids + benzoyl peroxide
Moderate: add topical ABXs
Severe: add PO ABXs
Tx of Nodular (Cystic) Acne
Moderate: topical retinoids + benzoyl peroxide + topical ABXs
Severe: add PO ABXs
SEs of Isotretoin
metabolic effects --> hyperglycemia, hyperTG (look out for pancreatitis) hepatotoxicity teratogen ocular toxicity bld dyscrasias mucocutaneous rxns