The 4 Dermatology Lesions Every FNP Student Must Master Before Boards

Dermatology · 4 min read · October 28, 2026

Introduction

Dermatology questions on the AANP and ANCC exams can feel like a game of spot-the-difference. You will be given a clinical vignette and a description of a skin lesion, and you have to decide whether to reassure the patient, scrape it, or biopsy it immediately. The good news? Board exams tend to test the same high-yield presentations over and over again. Let's break down the core skin lesions you are guaranteed to see on exam day so you can walk in with total confidence.

1. Actinic Keratosis vs. Squamous Cell Carcinoma

Actinic keratosis (AK) is the ultimate pre-malignant skin lesion. It typically appears in fair-skinned older adults with a history of cumulative sun exposure as rough, scaly papules or plaques on sun-exposed areas like the face, scalp, and dorsal hands. Patients often say they feel the lesion before they see it—it feels like sandpaper.

Board Distinction: AK is non-invasive and confined to the epidermis. Treatment options include cryotherapy, 5-fluorouracil (5-FU) cream, or imiquimod.
The Transition: If an actinic keratosis thickens, ulcerates, or fails to resolve with standard treatment, it can progress to Squamous Cell Carcinoma (SCC). SCC presents as a firm, hyperkeratotic nodule or plaque with central ulceration and scaling. It has metastatic potential, particularly when located on the lips, ears, or in immunosuppressed patients.

Clinical Pearl: Always remember the rule of thumb for AK: Feel before you see. If a patient complains of a rough patch on their forehead or scalp that feels like sandpaper, think actinic keratosis first.

2. Basal Cell Carcinoma: The Pearly Papule

Basal cell carcinoma (BCC) is the most common skin cancer in humans. Fortunately, it is slow-growing and rarely metastasizes, but it is locally destructive if left untreated.

Classic Presentation: Look for a pearly, translucent papule with rolled borders and prominent telangiectasias (surface blood vessels), most commonly on the face, neck, or trunk. Central ulceration (a "rodent ulcer") is also a classic hallmark.
Board Management: The definitive diagnosis requires a shave or punch biopsy, followed by referral for surgical removal (such as Mohs micrographic surgery for facial lesions).

Clinical Pearl: When you read "pearly papule with telangiectasias" in a stem, lock in Basal Cell Carcinoma immediately. Do not confuse this with the scaly, rough texture of actinic keratosis or squamous cell carcinoma.

3. Malignant Melanoma and the ABCDEs

Malignant melanoma accounts for the vast majority of skin cancer deaths. Board exams heavily test your ability to recognize early warning signs using the classic ABCDE criteria:

A - Asymmetry: One half does not match the other half.
B - Border irregularity: The edges are notched, ragged, or blurred.
C - Color variation: Pigmentation is not uniform; shades of brown, black, tan, red, or white may be present.
D - Diameter: Greater than 6 mm (the size of a pencil eraser), though melanomas can sometimes present smaller.
E - Evolving: A lesion that is changing in size, shape, color, or elevation, or developing new symptoms like pruritus or bleeding.

Clinical Pearl: The single most important prognostic factor for malignant melanoma is tumor thickness (Breslow depth). Deeper lesions carry a significantly higher risk of metastasis and lower survival rates.

4. Atopic Dermatitis and Psoriasis: The Itch That Rashes

Inflammatory skin conditions are a staple of FNP exams, and you must know how to differentiate atopic dermatitis from plaque psoriasis based on anatomical distribution and appearance.

Atopic Dermatitis (Eczema): Known as "the itch that rashes." It is characterized by intensely pruritic, erythematous papules and plaques, often with excoriations and lichenification from chronic scratching. In adults and older children, it classically affects the flexural creases (antecubital and popliteal fossae).
Plaque Psoriasis: Presents with well-demarcated erythematous plaques covered by silvery-white scales. It favors extensor surfaces, particularly the elbows and knees, as well as the scalp and lumbosacral region. Scraping the scale reveals tiny blood vessels bleeding through, known as the Auspitz sign.

Conclusion

Dermatology doesn't have to be a guessing game on your board exam. By focusing on key descriptive words—like pearly for basal cell carcinoma, sandpaper for actinic keratosis, and silvery scale for psoriasis—you will quickly identify the correct answer choice. You have put in the hard work to master this material, and you are more than ready to pass your boards.

Ready to take your board prep to the next level? Head over to thefnpreview.com to access thousands of high-yield practice questions, detailed rationales, and expert study tools designed specifically for future nurse practitioners.