CDT Cheat Sheet 2026

The 30 highest-yield CDT facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. Which grade in the ICDRG system represents a weak positive patch test reaction? → + (weak positive)
2. The principle of 'non-maleficence' in dermatology ethics BEST describes the obligation to: → Avoid actions that could cause unnecessary harm to the patient
3. What is the role of sebaceous glands? → Sebum production
4. Which standard of practice is MOST important for ensuring quality in Laboratory Procedures & Biopsies? → Following evidence-based protocols while adapting to specific circumstances
5. Why is patient identification important before any procedure? → To avoid patient confusion
6. Which PPE item is considered the FIRST line of defense against contact transmission in a dermatology setting? → Gloves
7. Which standard of practice is MOST important for ensuring quality in Common Skin Conditions & Treatment? → Following evidence-based protocols while adapting to specific circumstances
8. Which type of skin cancer most commonly arises from sun-damaged skin of the lower lip and presents as a scaly, non-healing ulceration? → Squamous cell carcinoma
9. What is the primary purpose of applying a topical corticosteroid under occlusion (covered with plastic wrap)? → To enhance drug absorption and penetration into the skin
10. Which document grants a healthcare proxy the authority to make medical decisions for an incapacitated dermatology patient? → Durable power of attorney for healthcare
11. A patient develops a Tyndall effect after hyaluronic acid filler injection to the tear trough. What does this bluish discoloration indicate? → Superficial placement of filler causing light scattering
12. A slit-skin smear is primarily used to diagnose which condition? → Leprosy
13. Which type of skin cancer most commonly arises from hair follicles and presents as a pearly, translucent nodule with rolled borders and telangiectasia? → Basal cell carcinoma
14. Arrector pili muscles attach to hair follicles and are responsible for: → Producing goosebumps
15. When counseling patients about tanning beds, which statement is most accurate? → Indoor tanning increases melanoma risk by approximately 75% when first used before age 35
16. During photodynamic therapy (PDT) with aminolevulinic acid (ALA), the incubation period before light activation typically lasts: → 1–3 hours
17. Phototesting (MED determination) measures the minimum erythema dose. This test is used to: → Determine a patient's UV sensitivity threshold for phototherapy dosing
18. Which situation constitutes a REPORTABLE ethical violation for a CDT? → Performing a procedure outside the scope of practice without supervision
19. The dermo-epidermal junction (DEJ) is composed primarily of which structural component? → Basement membrane with Type IV collagen and laminin
20. What is the primary dermatologic use of fluorouracil (5-FU) cream? → Treating actinic keratoses and superficial skin cancers
21. A patient with HIV presents with violaceous nodules on the lower extremities. Which diagnosis should be considered first? → Kaposi sarcoma
22. What is the MINIMUM recommended contact time for a 70% isopropyl alcohol wipe to effectively disinfect a hard, non-porous surface? → 30 seconds
23. Which of the following best describes an actinic keratosis (AK)? → A premalignant lesion that may progress to squamous cell carcinoma
24. When a conflict arises between standard procedures and a unique situation in Common Skin Conditions & Treatment, what should a CDT professional prioritize? → Safety and ethical obligations while seeking expert consultation
25. Nikolsky's sign, where lateral pressure on intact skin causes blistering, is positive in which condition? → Pemphigus vulgaris
26. Which symptom indicates a phototherapy overdose reaction requiring immediate intervention? → Severe blistering and pain
27. A patient presents with grouped vesicles on an erythematous base following a dermatomal distribution on the trunk. Which condition does this describe? → Herpes zoster (shingles)
28. A patient on isotretinoin asks if they can get a wax hair removal treatment. The correct response is: → Waxing should be avoided due to increased skin fragility and risk of skin lifting
29. Erythema multiforme minor is most commonly triggered by: → Herpes simplex virus infection
30. When instructing a patient to apply a topical medication to the periorbital area, which caution is most critical? → Avoid getting the medication into the eyes