Derma Flashcards
_____ is an autoimmune disease of unclear etiology in which the body essentially becomes allergic to its own skin
Pemphigus vulgaris
Pathology of Pemphigus vulgaris
Antibodies are produced against antigens in the intercellular spaces of the epidermal cells. They attack the “glue” that holds the epidermal
cells together
Pemphigus vulgaris is most often idiopathic, but _____
can occasionally cause
ACE inhibitors or penicillamine
____occurs in patients age 30s and 40s, whereas ____
occurs in those age 70s and 80s.
pemphigoid Vulgaris
bullous pemphigoid
Which is more serious?
pemphigoid Vulgaris
bullous pemphigoid
Pemphigus vulgaris is a much more serious and potentially life-threatening disease than pemphigoid
The presence of the _____ (the easy removal of skin by just a little pressure from the examiner’s finger, pulling the skin off like a sheet) is seen in pemphigus vulgaris,
staphylococcal scalded skin syndrome, and toxic epidermal necrolysis
Nikolsky sign
The lesions of ____ are painful, not pruritic.
pemphigus vulgaris
pemphigus vulgaris
The most accurate diagnostic test is to biopsy the skin and to use immunofluorescent stains. These stains will detect _____
intercellular deposits of IgG and C3 in the epidermis
Tx of pemphigus vulgaris
Treatment is with systemic glucocorticoids, such as prednisone. Topical steroids will not be sufficiently strong
Tx of PV
For those in whom steroids are ineffective or not tolerated, you can use
azathioprine, mycophenolate, or cyclophosphamide.
Rituximab and IVIG are also effective.
_____2× as common as pemphigus vulgaris and occurs in elderly persons age 70s and 80s. It can also be drug induced with sulfa drugs, including furosemide, penicillamine, and others.
Bullous Pemphigoid
Pathology of Bullous Pemphigoid
The defect occurs at the dermo-epidermal junction, so the layer of skin that separates off is much thicker
DX of Bullous Pemphigoid
The most accurate diagnostic test is a biopsy with immunofluorescent antibodies at the dermo-epidermal junction (basement membrane).
TX of Bullous Pemphigoid
Systemic steroids, such as prednisone, are the standard means of treatment.
Alternative TX of Bullous Pemphigoid
Tetracycline or erythromycin combined with nicotinamide is the alternative to steroids. Use topical steroids only if no oral lesions are present
___ is a disorder of porphyrin metabolism. Deficiency
of the enzyme uroporphyrinogen decarboxylase results in an abnormally high accumulation
of porphyrins, which then leads to a photosensitivity reaction
Porphyria cutanea tarda
Asscn of Porphyria cutanea tarda
porphyria cutanea tarda is associated with increased liver iron stores. Diabetes is found in 25% of patients.
HIV, alcoholism, liver disease, chronic hepatitis C, or a woman taking oral contraceptives
SSx of Porphyria cutanea tarda
Fragile, nonhealing blisters are seen on the sun-exposed parts of the body, such as the backs of the hands and the face.
This leads to hyperpigmentation of the skin in general and hypertrichosis of the face
Dx of Porphyria cutanea tarda
The diagnostic test is a level of urinary uroporphyrins. Uroporphyrins are elevated 2–5× above the coproporphyrins in this disease
Tx of Porphyria cutanea tarda
The best initial step in management is to stop drinking alcohol (although it is unlikely to be effective) and to discontinue all estrogen use
PCT
The most effective therapy to use if this is insufficient
is _______
phlebotomy to remove iron.
the antimalarial drug ______increases the excretion of porphyrins
chloroquine
______ is a hypersensitivity reaction most often mediated by IgE and mast cell activation, resulting in evanescent wheals and hives
Acute urticaria
The most common causes of acute urticaria are:
allergic reactions to medications, insect bites, and foods, and occasionally, the result of emotions
MC meds causing urticaria
aspirin, NSAIDs, morphine, codeine, penicillins, phenytoin, and quinolones
MC food causing urticaria
The most common foods are peanuts, shellfish, tomatoes, and strawberries.
Acute urticaria lasts____weeks in duration and two-thirds of cases are self-limited.
<6
Urticaria is treated with______
H1 antihistamines
What should never be used for urticaria
Astemizole and terfenadine should never be used
and are no longer marketed; they cause potentially fatal rhythm disturbances particularly when combined with other medications, such as macrolide antibiotics, because of their effect on the hepatic P450 system.
What to be done when trigger cant be avoided?
“desensitization” when the trigger cannot be avoided, e.g., a beesting in a farmer
______ must be stopped prior to desensitization because they inhibit epinephrine, which may be used if there is an anaphylactic reaction
Beta-blocker medications
____ is a milder version of a hypersensitivity reaction compared with urticaria. This is the “typical” type of drug reaction and is lymphocyte mediated
A morbilliform rash
Characteristic rash of morbiliform rash
It is a generalized, maculopapular eruption that blanches with pressure.
Erythema Multiforme MCC
most common cause of EM is a reaction to infection
MC characteristic feature of morbiliform rash
The most characteristic feature of EM is target-like lesions that occur especially on the palms and soles
characteristic rash of morbiliform rash
These lesions can also be described as “iris-like.” Bullae are not uniformly found. EM of this type usually does not involve mucous membranes
SJS usually involves ____ of the total body surface area, and the overall mortality rate is ____
<10 to 15%
<5 to 10%.
Best initial Tx for SJS
The best initial therapy for severe disease is IV
immunoglobulins. Other therapies of unclear value are cyclophosphamide, cyclosporine, and thalidomid
_____is the most serious version of a cutaneous
hypersensitivity reaction. Mortality may be as high as 40 to 50%.
Toxic epidermal necrolysis (TEN)
TEN has certain features similar to staphylococcal scalded skin syndrome; however, TEN is drug induced
as opposed to being caused by a _____ coming from an organism.
toxin
Dx test for TEN
The diagnosis is usually clinical. The most accurate diagnostic test is a skin biopsy,
which will reveal full thickness epidermal necrosis. A skin biopsy is usually not necessary
MCC of death in TEN
Sepsis is the most common cause of death, but prophylactic systemic antibiotics are not indicated. Systemic steroids are not effective and may, in fact, decrease survival.
_____ is a localized inflammatory condition of the skin or
panniculitis. It is secondary to recent infections or inflammatory conditions. It is also associated
with pregnancy.
Erythema nodosum (EN)
MCC of Erythema nodosum (EN)
The most common causes of EN are recent streptococcal infections, coccidioidomycoses, histoplasmosis, sarcoidosis, inflammatory bowel disease, syphilis, TB, and
hepatitis.
SSx of EN
Erythema nodosum consists of multiple painful, red, raised nodules on the anterior surface of the lower extremities
Skin infection characterized by multiple macules (usually asymptomatic), varying in color from white to brown.
Tinea versicolor
Tinea versicolor etiology
Pityrosporum orbiculare (Malassezia furfur).
SSx of tinea versicolor
Tan, brown, or white scaling macular lesions that tend to coalesce; found on chest, neck, abdomen, or face. Lesions do not tan
Tx of tinea versicolor
Topical selenium sulfide, clotrimazole, ketoconazole, or oral itraconazole.
Describe Intertriginous Candida infection
Well-demarcated, erythematous, itchy, exudative patches, usually rimmed with small red-based pustules that occur in the groin, gluteal folds (diaper rash), axilla, umbilicus, and inframammary areas.
Describe Candida vulvovaginitis
White or yellowish discharge with inflammation of the vaginal wall and vulva. Common in pregnant women and patients with diabetes mellitus
TX of Candida infxn
Topical nystatin, clotrimazole, miconazole, ciclopirox, econazole, or terconazole
The most common bacterial organisms to cause skin infections of any kind are ______ and _____
Staphylococcus
and Streptococcus
If a patient is allergic to penicillin, but the reaction is only a rash, then _____ can be safely used
cephalosporins
