Clinical Morphology Flashcards
What are the four core characteristics of clinical diagnosis of a rash?
- Morphology of individual lesion
- Location
- Color
- Configuration (i.e. how the lesions are grouped)
What is a papule vs a macule vs a patch vs a plaque? Give an example of each
Macule - flat lesion, color change only, <1 cm (i.e. freckle)
Patch - flat lesion, color change only, >1 cm (i.e. vitiligo)
Papule - raised but superficial lesion with distinct borders, <1 cm (i.e. comedone)
Plaque - raised but superficial lesion with distinct borders, >1 cm (i.e. psoriasis) (remember it’s a plaque cuz Hellen Keller reads her Braille plaque)
What is a nodule vs a wheal? Give an example of each.
Nodule - hefty, solid, deep, dome-shaped lesion (i.e. dermatofibroma)
Wheal - transient raised lesion without surface change (smooth papula or plaque), due to dermal edema, <24 hours (i.e. urticaria)
What are vesicles vs bullae vs pustules?
Vesicle - Fluid-containing blister <1cm, i.e. shingles
Bulla - Fluid-containing blister >1cm. I.e. bullous pemphigus
Pustule - Vesicle filled with pus (purulent fluid) i.e. acne
What are secondary skin changes?
Skin changes on or around the primary lesion which are not necessarily due to the original lesion (i.e. non-smooth surface characteristics, or things happening around the lesion)
What is desquamation vs excoriation?
Desquamation - Peeling off of sheets of stratum corneum
Excoriation - erosion due to scratching (self-induced erosions)
What is erosion vs ulcer vs fissure?
Erosion - superficial lost of skin (epidermis)
Ulcer - Loss of deeper skin (i.e. dermis, subcutaneous fat)
Fissure - linear erosion / ulcer
What is scale vs crust?
Scale - Shedding / flaking of the stratum corneum, usually due to thickening / increased cell turnover (i.e. psoriasis has scaling of plaques)
Crust - dried exudate of some kind (i.e. impetigo)
What is an eschar?
A dark scab, typically in the center of an area of large skin loss
Define atrophy and induration?
Atrophy - Thinned, depressed skin (usually secondary to corticosteroids)
Induration - Dermal thickening (not a groove man, dermal THICKENING). Duracion is the french word for hardness
Define lichenification.
Thickening of skin with accentuation of skin lines
What is a telangiectasia and when do they commonly occur?
Dilated superficial blood vessels, often in chronic sun damage
What is the cause of petechia / purpura and do they often blanch?
Petechiae - fine, speckled, red color -> due to thrombocytopenia / microhemorrhages, non-blanching (not due to little capillaries)
Purpura - Larger than petechiae, also due to extravasated blood (i.e. a bruise), may even be a palpable plaque in vasculitis (i.e. palpable purpura). They are larger hemorrhages -> also do not blanch
What is hypo vs hyper vs depigmentation?
Hypopigmentation - lighter than normal color, i.e. tinea versicolor
Hyperpigmentation - darker than normal color (as compared to skin) i.e. freckle
Depigmentation - absence of skin pigment whatsoever (ie. vitiligo)
What is an serpiginous vs arcuate configuration?
Serpiginous - curving irregularly, like a snake
Arcuate - Forming part of a circle (an arc)
