Dermatology from PANCE Pearls Flashcards
What is a Cutaneous Drug Reaction
Medication-induced changes in skin and mucous membranes
Most are hypersensitivity reactions
Most are self-limiting if offending drug is discontinued
What are triggers for Cutaneous Drug Reactions
Antigen from foods, insect bites, drugs, environmental, exercise, infectious
What is a Type I Hypersensitivity Reaction
Ig-E mediated
Urticaria and Angioedema
Immediate
What is a Type II Hypersensitivity Reaction
Cytotoxic, Ab-mediated
What is a Type III Hypersensitivity Reaction
Immune Antibody-Antigen Complex
Such as drug-mediated vasculitis and serum sickness
What is a Type IV Hypersensitivity Reaction
Delayed (Cell Mediated)
Such as Erythema Multiforme
What is an Exanthematous/Mobiliform Rash
When does the rash begin
What types of drugs cause it
Generalized, bright red macule and papules that coalesce to form plaques
Rash starts 2-3 days after initiation of meds
Antibiotics, NSAIDS, Allopurinol and Thiazide Diuretics
What is an Urticarial Rash
When does the rash begin
What types of drugs cause it
Blanchable, edematous pink papule, wheals or plaques
Occurs within minutes to hours of drug administration
Antibiotics, NSAIDS, Opiates and radio contrast
What is Erythema Multiforme
What types of drugs cause it
Target Lesions
Sulfonamides, Penicillins, Phenobarbital, Dilantin
What general sx are seen with drug reactions
Fever, abdominal pain, joint pain
Tx of drug reactions Exanthematous Urticaria Erythema Minor Anaphylaxis
Discontinue medication is #1 Exanthematous: Histamines Urticaria: Corticosteroids, Antihistamines Erythema Minor: Sx Anaphylaxis: IM Epinephrine
What is Urticaria/Angioedema
Hives
A type I HSN IgE
Sx or Urticaria
Blanchable, edematous pink papules, wheals or plaques
Darier’s Sign: Localized urticaria appearing where the skin is rubbed (histamine induced)
Angioedema: Painless, deeper form of urticaria affecting lips, tongue, eyelids, hands feet and genitals
Tx of Urticaria
Antihistamines
Eliminate triggers
H2 blockers
Corticosteroids
What is Erythema Multiforme
Acute self-limited type IV HSN reaction
What are common drugs that result in Erythema Multiforme
Sulfa Drugs
Beta-Lactams
Phenytoin
Phenobarbital
Sx of Erythema Multiforme
Traget lesions
Dusty-violet red purpuric macule/veicle or bullae in center surrounded by pale edematous rim and peripheral red halo
Fever
Tx of Erythema Multiforme
Discontinue drugs
Treat sx
Antihistamines, Analgesics, Skin care, Steroids
What is Steven Johnson Syndrome and TEN
What are drugs that cause it
Drug Eruption
SJS 30% surface affcted
Usually with Sulfa and Anticonvulsants
If infectious: Mycoplasma, HIV, HSV
Sx of Steven Johnson Syndrome and TEN
Fever, URI sx, widespread blisters that begin on trunk/face, erythematous/pruritic macules with epidermal detachment (positive Nikolsky sign)
TX of Steven Johnson Syndrome and TEn
Treat like severe burns
Hydrate!
What is Basal Cell Carcinoma
Most common type of skin cancer in US
Found in fair-skinned people with prolonged sun exposure, xeroderma
Slow growing, locally invasive but low incidence of mets
Sx of Basal Cell Carcinoma
Flat firm area with small raised, translucent/pearly/waxy papule with central ulceration and raised rolled borders
Usually seen on face/nose/trunk
Friable (bleeds easily)
May have Telengiectasis
Dx of Basal Cell Carcinoma
Punch or Shave Biopsy, see basophilic cells
Tx of Basal Cell Carcinoma
Electric Desiccation/curettage
Excision, cryosurgery
What is a Squamous Cell Carcinoma
Second most common skin cancer
Often preceded by actinic keratosis, HPV infection, sun exposure
Usually found on lips, hands, neck, and head
What is Bowen’s Disease
Squamous Cell Carcinoma in situ
Slow growing, rarely mets
Sx of Squamous Cell Carcinoma
Red, Elevated nodule with adherent white scaly or crusted bloody margins
Dx of Squamous Cell Carcinoma
Biopsy
Epidermal and Dermal cells with large pleumorphic hyperchromatic nuclei
Tx of Squamous Cell Carcinoma
Excision
What is Melanoma
Skin Cancer
UV radiation is most common cause
Aggressive, high Mets potential
Light-skinned, light hair, light eye color most at risk
Sx of Melanoma
ABCDE
Asymmetry, Irregular borders, Dark Color, >6mm Diameter, Evolution
What is the most important factor for prognosis of a Melanoma
Thickness
Dx of Melanoma
Full thickness wide excisional biopsy with lymph node biopsy
NO Shave Biopsy
Tx of Melanoma
Excision with lymph node dissection
What is Cellulitis
Acute, spreading superficial infection of dermal, subcutaneous tissues caused by S. Aureus, Group A Strep
Usually occurs after a break in the skin (trauma, surgical wounds)
Sx of Cellulitis
Macular erythema (margins flat, not sharply demarcated), swelling, warmth, and tenderness Fevers, Chills, Lymphangitis, Myalgias
Tx of Cellulitis
Cephalexin, Dicloxacillin
Erythromycin or Clindamycin if PCN allergy
Vancomycin or Linezolid if MRSA
Cat Bite (Pasteurella Multocida): Augmentin, Doxy if PCN allergy
Puncture Wound: Ciprofloxacin
What is a 1st degree burn Depth Appearance Sensatin Capillary Refill Prognosis
Superficial Epidermis Erythematous and Dry, Painful, tender to touch Refill Intact, Blanches with pressure Heals within 7 days, No scarring
What is a 2nd degree burn (Superficial Partial Thickness) Depth Appearance Sensatin Capillary Refill Prognosis
Epidermis + Superficial portion of dermis
Erythematous, Pink, Moist, Weeping, Blisters
MOST painful of all burns, Very tender to touch
Refill Intact, blanches with pressure
Heals within 14-21 days, No scarring but leaves pigment changes
What is a 2nd degree burn (Deep Partial Thickness) Depth Appearance Sensatin Capillary Refill Prognosis
Epidermis into deep portion of dermis
Red, yellow, pale white, dry, Blisters
Not usually painful, Possible pain with pressure
No Refill
Heals in 3 weeks - 2 months, Scarring is common
What is a 3rd degree burn Depth Appearance Sensatin Capillary Refill Prognosis
Extends through entire skin Waxy, White, Leathery, Dry Painless No Refill Heals in months, Does not spontaneously heal well
What is a 4th degree burn Depth Appearance Sensatin Capillary Refill Prognosis
Entire skin into underlying fat, muscle, bone Black, Charred, Eschar, Dry Painless No Refill Does not Heal
What is a minor burn
What is a major burn
>25% total body surface area in adults >20% total boy surface area in young/old >10% full thickness burns Involves the face, hands, perineum, feet Cross major joints Circumferential
Tx of Burns
Clean with mild soap and water NO ice or ointments Debridement Tx pain: Acetaminophen, NSAIDS, Opioids Abx Silver Sulfadiazine (none on face) Aloe Vera Dressings for partial and full-thickness, fingers and toes individually wrapped IV Fluid Resuscitation: Parkland Formula (Lactated Ringers 4mL/kg/%total surface area for 24 hours. Give half in the first 8 hours, the other half in the remaining 18 hours
Tx of Chemical Burns
Irrigate profusely with running water for 20 minutes
What is a Pressure Ulcer
Stage I - IV
Stage I: Superficial, nonblanchable redness that does not dissipate after pressure is relieved
Stage II: Epidermal damage into dermis. Looks like a blister or abrasion
Stage III: Full thickness of skin and may extend into subcutaneous layer
Stage IV: Deepest, Extending into muscle, tendon or bone
