Clinical High-Yield · 11 min read · April 28, 2026
Dermatology is one of the most visual specialties in medicine — which creates a unique challenge for a written board exam. The boards cannot show you a photograph (at least not on the AANP and ANCC written exams), so they describe lesions in precise clinical language. Your job is to translate that description into a diagnosis. Here is the complete high-yield guide.
The boards use specific dermatological terminology to describe lesions. If you do not know this vocabulary, you cannot answer dermatology questions correctly — regardless of how well you know the diseases.
Macule: Flat, non-palpable color change, <1 cm. Examples: freckle, café-au-lait spot, petechiae.
Patch: Flat, non-palpable color change, >1 cm. Examples: vitiligo, port-wine stain.
Papule: Elevated, palpable, solid lesion, <1 cm. Examples: wart, molluscum contagiosum, acne (closed comedo).
Plaque: Elevated, palpable, flat-topped solid lesion, >1 cm. Examples: psoriasis, lichen planus.
Nodule: Elevated, palpable, solid lesion, 1–2 cm, deeper than a papule. Examples: lipoma, dermatofibroma, rheumatoid nodule.
Vesicle: Elevated, fluid-filled lesion, <1 cm. Examples: herpes simplex, varicella, contact dermatitis.
Bulla: Elevated, fluid-filled lesion, >1 cm. Examples: bullous pemphigoid, pemphigus vulgaris, second-degree burn.
Pustule: Elevated, pus-filled lesion. Examples: acne (pustular), folliculitis, impetigo.
Wheal (hive): Elevated, edematous, transient lesion with central pallor and surrounding erythema. Examples: urticaria, insect bite reaction.
Cyst: Elevated, encapsulated, fluid or semi-solid filled lesion. Examples: epidermoid cyst, pilar cyst.
Psoriasis: Chronic, autoimmune, inflammatory skin condition. Classic presentation: well-demarcated, erythematous plaques with silver-white scale, located on extensor surfaces (elbows, knees), scalp, and lower back. The Auspitz sign (pinpoint bleeding when scale is removed) is pathognomonic. Nail findings: pitting, onycholysis, "oil drop" sign. Associated with psoriatic arthritis (asymmetric oligoarthritis, DIP involvement, sausage digits). Treatment: mild-moderate: topical corticosteroids (first-line), vitamin D analogs (calcipotriene), topical retinoids. Moderate-severe: phototherapy (UVB), methotrexate, cyclosporine, biologics (TNF inhibitors, IL-17 inhibitors, IL-23 inhibitors).
Atopic Dermatitis (Eczema): Chronic, relapsing inflammatory skin condition associated with atopy (asthma, allergic rhinitis). Presentation varies by age: infants — cheeks, scalp, extensor surfaces; children and adults — flexural surfaces (antecubital and popliteal fossae), neck. Intensely pruritic. Skin is dry, lichenified (thickened with accentuated skin lines from chronic scratching). Treatment: moisturizers (cornerstone of management), topical corticosteroids (first-line for flares), topical...