Primary Skin Lesions Flashcards
Macule
A flat colored lesion, not raised above the surface of the surrounding skin. < 2cm in diameter.
e.g. A freckle is a pigmented Macule. Macules can be brown, blue, red, etc.
(Bigger Macule is a Patch)
Patch
A large (> 2cm in diameter) flat lesion with a color different from surrounding skin.
(Patch is a larger Macule)
Macule vs. Patch?
Macule (< 2cm) is a small Patch (> 2cm)
Papule
A small solid lesion raised above the surface of the surrounding skin and is palpable (< 0.5cm in diameter).
e.g. closed comedone/whitehead in acne
(Bigger Papule is a Nodule)
Nodule
A larger firm solid lesion raised above the surface of the surrounding skin (0.5 - 5.0 cm in diameter)
(A nodule is a bigger papule)
Papule vs. Nodule
Papule (< 0.5cm) is a small Nodule (0.5 - 5.0 cm)
Tumor
A solid raised growth > 5cm in diameter whereas a nodule is 0.5 - 5.0cm
Plaque
Large (> 1cm) flat-topped raised lesion. Edges may be distinct (e.g. psoriasis) or gradually blend with surrounding skin (e.g. eczematous dermatitis)
Vesicle
A small fluid filled-lesion raised above the plane of surrounding skin. (< 0.5cm in diameter)
Fluid is often visible and the lesions are translucent
e.g. vesicles in allergic contact dermatitis caused by poison ivy (Toxicodendron)
(Pustule is a type of vesicle with leukocytes in it)
Pustule
A Pustule is a Vesicle filled with leukocytes.
Note: presence of pustules does not necessarily signify the existence of an infection.
Bulla
A fluid filled raised and often translucent lesion > 0.5cm in diameter
Vesicle (& Pustule) vs. Bulla
Vesicle (and Pustule) smaller (< 0.5cm) than bulla (> 0.5cm)
Wheal
A raised, erythematous, edematous papule or plaque. A wheal usually represents short-lived vasodilatation and vasopermeability
Telangiectasia
A dilated, superficial blood vessel
