Ch. 17 Derm Flashcards
What do you call a Flat, nonpalpable, circumscribed lesion < 5 mm in diameter?
Macule
What do you call a Flat, nonpalpable, circumscribed lesion > 5 mm in diameter?
Patch
What do you call a Palpable, circumscribed lesion < 5 mm in diameter, raised above skin surface?
Papule
What do you call a Palpable lesion > 5 mm in diameter, raised above skin surface?
Plaque
What do you call a Firm lesion arising in subcutaneous tissue < 2 cm in diameter?
Nodule
What do you call a Firm lesion arising in subcutaneous tissue > 2 cm in diameter?
Tumor
What do you call a Raised, fluid-filled, superficial lesion < 5 mm in diameter?
Vesicle
What do you call a Raised, fluid-filled, superficial lesion > 5 mm in diameter?
Bulla
What do you call a Pus-filled superficial lesion < 5 mm in diameter?
Pustule
What do you call a Pus-filled lesion arising in subcutaneous tissue > 5 mm in diameter?
Abscess
What do you call a Evanescent, raised, round, or flat-topped lesion caused by edema?
Wheal
What is the difference between erythema multiforme minor and erythema multiforme major?
EM Minor - Rash without mucosal involvement
EM Major - Rash with mucosal involvement
Describe the rash of Erythema Multiforme.
Erythematous, papular rash that appears over 72 hours, most
commonly on palms and dorsal surface of forearms but also on feet, face,
and lower extremities, usually < 10% BSA.
■ Papules may evolve to target lesions with a characteristic central dusky or
purple zone surrounded by a pale ring and then third erythematous halo.
■ Lesions may have a vesicular or bullous appearance.
Migratory annular and polycyclic erythematous eruption, cutaneous manifestation of acute rheumatic fever.
Erythema marginatum
Expanding red lesion with central clearing at site of tick bite, Lyme disease.
Erythema migrans
Target lesions,
± mucosal involvement, many causes.
Erythema multiforme
Tender, raised red
nodules on legs, many causes.
Erythema nodosum
What is the treatment for Erythema Multiforme?
Symptomatic tx and topical steroids
If mucosal involvement –> oral prednisone +/- hospitlization if impaired oral intake
+/-antiviral prophylaxis to prevent recurrence
_____ and _____ are desquamating, erythematous rashes distinguished from each other only by extent of disease based on total body surface area (TBSA).
SJS and TEN
How does the total body surface area differ between SJS and TEN?
SJS involves < 10% TBSA and TEN > 30% TBSA (SJS/TEN overlap is in-between).
What is a significant risk factor for SJS&TEN?
HIV (1000x increased risk)
Is Nikolsky sign positive or negative in SJS/TENS?
Positive – Skin separates when gentle lateral pressure is applied
What is the treatment for SJS/TENS?
ICU or burn unit for skin care fluid/electrolyte correction
What is the mechanism of injury for Staphylococcal scalded skin syndrome (SSSS)?
Caused by an exotoxin produced by
S. aureus that is released into the bloodstream causing superficial separation of the skin and widespread painful erythema and blistering.