Terminology for morphology: macule, patch, papule, plaque, vesicle, bulla, pustule, nodule, cyst, crust, scale, lichenification, erosion, ulcer, wheal


Approach to rashses:


Step 1: describe morphology.


Step 2: describe distribution and configuration.


Step 3: consider which skin layers are involved.


Step 4: apply information to clinical context and story.


Examples: flat or raised, size, color, shape, texture, configuration, distribution


References: AAD Basic Dermatology Curriculum, Dermatology by Bolognia et. al., Lookingbill and Mark's Principles of Dermatology, First Aid USMLE Step 1 2020, First Aid USMLE Step 2 CK