Master the Boards: Dermatology Flashcards
What type of biopsy may be done in suspected basal cell carcinoma?
A shave biopsy is ok
What is the pathogenic origin of Kaposi sarcoma?
Human herpes virus 8
Kaposi sarcoma is red-purple because it is more vascular. Besides the skin what other two areas may it be found in?
GI tract
Lung
How is Kaposi sarcoma treated?
Generally no surgery. Treat AIDS or HIV with antiretrovirals and generally regresses.
Occasionally can use intralesional vincristine or interferon injections
Should actinic keratosis be removed?
Yes, they should be removed with curettage, cryotherapy, laser, or topical 5-FU
Overactivity of mast cells leads to what common skin disorder?
Eczema
Levels of what Ig are elevated in atopic dermatitis (eczema)?
What are general skin care measures for tx?
IgE
Avoid irritants (bathing, soap, washcloths)
Stay moisturized
Cotton is less irritating than other clothing
What are topical treatments of atopic dermatitis?
Steroids
Tacrolimus and pimecrolimus
*Antihistamines can also be used (including doxepine in severe disease)
What are topical treatments for local psoriasis?
Steroids
Vitamin A and vitamin D ointment
Coal tar preparation
Tacorlimus and pimecrolimus on more delicate areas
What is treatment for extensive psoriasis?
UV light
Anti-TNF drugs (e.g. etanercept, adalimumab, and inflliximab)
Methotrexate
Patient presents with a single lesion which disseminates but spares the palms and soles. What is the likely dx?
Pityriasis Rosea
The single lesion was the Herald patch which can spread to form a “Christmas tree” like rash distribution
What is tx of Pityriasis roasea?
Usually remits on own but UV light and steroids can be used
What agents are helpful for seborrheic dermatitis (aka dandruff)?
Topical steroids and topical antifungals (e.g. ketocanzole)
These are helpful bc it is a hypersensitivity reaction to dermal infection with noninvasive dermatophytes
What common drug is associated with pemphigus vulgaris?
ACEi
Also penicillin, phenobarbital, and penicillamine
What disease presents with blisters which easily rupture, oral involvement, and fluid loss and infection?
What is Nikolsky sign (positive in this condition)?
Pemphigus vulgaris
Nikolsky sign: removal of superficial layer os skin with slight pressure
What is treatment of pemphigus vulgaris?
Systemic steroids (prednisone) Azathioprine or mycophenolate to wean patients off steroids Rituximab or IVIG in refractory cases
What disease presents with tense bullae?
What is the best initial therapy?
Mild disease responds to what other meds?
Bullous pemphigoid
Prednisone
Mild: Erythromycin, dapsone, and nicotinamide
Porphyrea cutanea tarda leads to blistering of the hands and feet. What two conditions is it associated with?
HCV
Hemochromatosis (iron overload)
Porphyrea cutanea tarda is a deficiency of what enzymes activity and what builds up?
What are underlying causes (environmental; 2)?
What procedural treatment helps?
Uroporphyrin decarboxylase defect leading to increased uroporphyrins (detected in urine)
Estrogen and alcohol
Phlebotomy to remove iron
Impetigo due to community-acquired MRSA can be treated with what agents (3)?
Doxycycline
Clindamycin
TMP/SMX
Skin infections with group A Strep (i.e. Strep pyogenes) can have what harmful sequela?
Post-strep glomerulonephritis
NOT rheumatic fever
What is a more severe disease, impetigo or erysipelas?
Which more commonly has a leukocytosis?
Erysipelas is more severe since deeper involvement and more likely to have fever and leukocytosis
(More commonly due to Strep)
Place the following in order of size (from small to large)
Carbuncle
Folliculitis
Furuncle
Folliculitis
Generally what is the best initial test for detecting fungal infection?
What is the most accurate test?
Initial: KOH
Accurate: Fungal culture
What is a major side effect of ketoconazole?
Antiandrogenic (gynecomastia)
What is the best initial therapy for tinea capitis (hair) and tinea unguium (nail)?
Terbinafine
Itraconazole close in efficacy
What are drugs which commonly cause hypersensitivity reactions? (6)
Penicillin Sulfas NSAIDs Lamotrigine Phenytoin Allopurinol
Erythema multiforme can be a precursor to more severe infections like Stevens-Johnson syndrome. However, what are other pathogenic causes?
Herpes or Mycoplasma
Sloughing off of epithelium and mucous membrane involvement is due to ______. What is tx?
Stevens-Johnson syndrome
IVIG
(Steroids are NOT helpful)
Toxic shock syndrome (TSS) and Staph scalded skin syndrome (SSSS) are both caused by _____.
What is tx?
Staphyloccous
Oxacillin or nafcillin if sensitive
What is the order of drug treatment for acne based on severity?
Topical benzoyl peroxide topical clindamycin/erythromycin topical vitamin A derivatives (e.g. tretinoin) oral antibiotics oral vitamin A/isotretinoin.
What type of biopsy is recommended in melanoma?
Full thickness bx
