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

Nickel is the most prevalent contact allergen worldwide, commonly found in jewelry, belt buckles, watches, and metal fasteners.

Question 2

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

Accepted Answer

Permanent hair dyes

Answer

PPD is a key ingredient in permanent dark hair dyes and is one of the most common causes of contact dermatitis from hair coloring products.

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

Balsam of Peru is a natural resin that cross-reacts with many fragrances, spices, flavorings, and topical preparations containing similar aromatic compounds.

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

Thiuram compounds are chemical accelerators added during the rubber vulcanization process, so thiuram mix sensitivity indicates rubber accelerator allergy rather than natural latex protein allergy.

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

Methylisothiazolinone (MI) is a preservative widely used in personal care products that became epidemic as a contact allergen after its expanded use in leave-on cosmetics.

(CDT) Certified Dermatology Tech Practice Test

(CDT) Certified Dermatology Tech Practice Test

CDT Allergy Testing & Patch Testing 3