Rash Flashcards
What is a rash?
Inflammatory skin erruption
Differential diagnosis of a rash os primarily based on morphology of the lesion:
1) First identify the primary lesion, this is the lesion that is the typical element of the eruption.
2) Determine the global reaction patern.
3) Distribution of the lesions (diffuse, isolate, localized, regional, universal)
Primary lesion:
initial lesion that has not been altered by trauma or manipulation, and has not regressed.
Secondary lesion:
Develops as the disease evolves or as the patient damages the lesion. ex) rubbing, scratching, infections.
Primary lesions:
Bulla
Macule
Nodule
Papule
Patch
Petechiae
Plaque
Pustule
Vesicle
Wheal
Bulla:
A circumscribed, elevated lesion that measures ≥ 1cm and contains serous or hemorrhagic fluid (ex: larger blister)
Macule:
circumscribed, nonpalpable discoloration of the skin that measure < 1cm in diameter.
Nodule:
A palpable, solid, round ellipsoid lesion measuring ≥1cm; it differs from a plaque in that it is more substantive in its vertical dimension compared with its breadth.
Papule:
An elevated, solid lesion that measures <1cm in diameter
Patch:
A circumscribed, nonpalpable discoloration of the skin that measures ≥1cm.
Petechiae:
Nonblanching reddish macules representing extravascular deposits of blood, measuring ≤ 0.3cm (less than the size of a pencil eraser).
Plaque:
A palpable, solid lesion that measures ≥1cm
Purpura:
Nonblanching reddish macules or papules representing extravascular deposits of blood, measuring > 0.3cm.
Pustule:
A lesion that contains pus; may be follicular (centered around the hair follicle) or nonfollicular.
Vesicle:
A circumscribed, elevated lesion that measures <1cm & contains serous or hemorrhagic fluid (ex:small blister)
Wheal:
A round or annular (ring-like), edematous papule or plaque that is characteristically evanescent, disappearing within hours; may be surrounded by a flare or erythema. (ex: hive)
Secondary lesion:
Atrophy
Crust
Erosion
Lichenification
Scale
Scar
Ulcer
Atrophy:
A depression in the skin resulting from thinning of epidermis, dermis and/or subcutaneous fat.
Crust:
A collection of dried blood, serum, and/or cellular depris.