CDT Allergy Testing & Patch Testing 3

Question 1

Which metal is the most common contact allergen identified by patch testing worldwide?

Accepted Answer

Nickel

Answer

Gold

Answer

Mercury

Answer

Copper

Question 2

Para-phenylenediamine (PPD) is a common patch test allergen primarily found in:

Accepted Answer

Permanent hair dyes

Answer

Chemical sunscreens

Answer

Rubber examination gloves

Answer

Topical antibiotic ointments

Question 3

Balsam of Peru is included in patch test panels primarily because it serves as a marker for sensitivity to:

Accepted Answer

Fragrances, spices, and aromatic compounds

Answer

Rubber compounds and latex

Answer

Hair dyes and dark pigments

Answer

Sunscreen UV filters

Question 4

A patient has a positive patch test to thiuram mix. This result indicates sensitivity to:

Accepted Answer

Chemical accelerators used in rubber vulcanization

Answer

Natural rubber latex proteins

Answer

Synthetic rubber polymer backbone

Answer

Carbon black fillers in rubber products

Question 5

Which preservative commonly found in rinse-off and leave-on cosmetics has become a leading cause of contact allergy?

Accepted Answer

Methylisothiazolinone (MI)

Answer

Sodium lauryl sulfate

Answer

Glycerin

Answer

Cetyl alcohol

Question 6

A healthcare worker with hand dermatitis tests positive to carba mix on patch testing. The most likely source of occupational exposure is:

Accepted Answer

Rubber examination gloves

Answer

Disinfectant cleaning solutions

Answer

Surgical scrub solutions

Answer

Iodine-based wound care products

Question 7

Topical corticosteroids at the patch test application site should be:

Accepted Answer

Discontinued for at least 1–2 weeks before testing on that skin area

Answer

Applied immediately before patch placement to prevent severe reactions

Answer

Applied only during the 48-hour waiting period for comfort

Answer

Used throughout testing to improve patient tolerance