Dermatology Evaluation

Start with the lesion itself. Everything else — color, shape, distribution, body site — appears once you've picked one, narrowed to the descriptors the remaining diagnoses actually use.

Primary lesions

MaculeFlat, circumscribed color change ≤0.5 cm; not palpable (freckle, petechiae).PatchFlat color change >0.5 cm — the large version of a macule (vitiligo, café-au-lait).PapuleRaised, solid lesion ≤0.5 cm (wart, molluscum, acne).PlaqueRaised, flat-topped, palpable lesion >0.5 cm; often coalesced papules (psoriasis, eczema).NoduleSolid palpable lesion >0.5 cm with depth into dermis/subcutis (cyst, lipoma, BCC).TumorA large nodule >2 cm; may be benign or malignant.WhealTransient edematous raised lesion (dermal edema) resolving within 24 h (urticaria).VesicleSmall fluid-filled blister ≤0.5 cm with clear serous fluid (HSV, varicella).BullaLarge fluid-filled blister >0.5 cm (bullous pemphigoid, burns).PustuleSmall circumscribed elevation containing purulent fluid (acne, folliculitis).AbscessLocalized collection of pus in the dermis/subcutis; fluctuant, warm, tender.

Secondary changes

ScaleFlakes of stratum corneum from abnormal keratinization (psoriasis silvery, seb derm greasy).CrustDried serum, blood, or pus on the surface (impetigo honey-colored).ErosionSuperficial loss of epidermis only; heals without scarring.UlcerDeeper loss of epidermis AND dermis; heals with scarring.FissureLinear crack in the skin, often painful (angular cheilitis, hand eczema).ExcoriationSuperficial abrasion from scratching; linear or punctate.LichenificationThickened skin with accentuated markings from chronic rubbing.AtrophyThinning of the skin; translucent, wrinkled, or depressed.ScarFibrous tissue replacing normal skin after injury.IndurationHardening/firmness of the skin, felt on palpation.

Physical exam text

Select findings above to build the SKIN exam paragraph.

Reference draft to support — not replace — clinical judgment. Differential is scored by descriptor overlap, not a validated algorithm; verify dosing and any red-flag disposition before charting.

Medical disclaimer. These tools are educational references intended for use by licensed clinicians. They do not constitute medical advice, do not establish a physician–patient relationship, and are not a substitute for clinical judgment, local protocols, or current guidelines. Verify all calculations and recommendations independently.