Primary skin lesions description

MACULE : a flat , colored lesion of less than 2 cms in diameter , not raised above the surface of the surrounding skin. A freckle or ephelid is a prototype pigmented macule .

 PATCH : a large ( greater than 2 cms ) flat lesion with a color different from the surrounding skin. This differs from a macule only is size .

PAPULE : a small, solid lesion, less than 0.5 cms in diameter , raised above the surrounding skin surface and hence palpable . ( example : a closed comedone or whitehead, in acne ).

 NODULE : a larger ( 0.5 -5.0 cms ) , firm lesion raised above the surface of surrounding skin . this differs from a papule only in size . ( example : a dermal nevomelanocytic nevus ).

TUMOR : a solid, raised growth greater than 5 cms in diameter .

 PLAQUE : a large ( greater than 1 cm ) , flat topped , raised lesion , edges may either be distinct ( example : psoriasis ) or gradually blend with surrounding skin ( example : eczematous dermatitis ) .

VESICLE : a small, fluid-filled lesion , less than 0.5 cm in diameter , raised above the plane of the surrounding skin. Fluid is often visible , and the lesions are translucent{example : vesicles in allergic contact dermatitis caused by toxicodendron (poison ivy)}.

 PUSTULE : a vesicle filled with leucocytes . note : the presence of pustules does not necessarily signify the existence of an infection .

BULLA : a fluid filled ,raised , often translucent lesion greater than 0.5 cm in diameter .

 WHEAL : a raised , erythematous , edematous papule or plaque , usually representing short lived vasodilatation and vasopermeability .

TELANGIECTASIA : a dilated , superficial blood vessel .