EXAMS AND ME

Monday, 20 July 2026

KOH Mount Test

1892: German dermatologist Paul Gerson Unna popularized the use of potassium hydroxide to clear keratinized tissues. KOH dissolved keratin while leaving the chitin-containing fungal cell walls intact, making fungi easier to identify microscopically.

Paul Gerson Unna and Nivea

German dermatologist Paul Gerson Unna played a crucial role in the creation of NIVEA Creme. In 1911, he introduced chemist Dr. Isaac Lifschütz—the inventor of the revolutionary water-in-oil emulsifier Eucerit—to Beiersdorf co-founder Dr. Oscar Troplowitz, laying the scientific foundation for the iconic skin cream.

Unna’s deep understanding of dermatology allowed him to identify Eucerit as the perfect base for a cosmetic skincare product. Because this new mixture was snow-white, Troplowitz named the cream "NIVEA," deriving it from the Latin word nix, nivis (meaning snow).

Early 20th Century: The KOH preparation became a standard diagnostic method in dermatology clinics for evaluating:

Tinea (ringworm)
Onychomycosis (nail fungus)
Pityriasis versicolor
Candidiasis

Snapshot

International Cake Day

The word "cake" derives from the Old Norse word kaka.

Ancient Origins (c. 2500 BCE): The earliest cakes were made in ancient Egypt. These were closer to sweetened breads than modern cakes and were prepared using flour, honey, nuts, and dried fruits. Egyptians were among the first to master baking techniques using ovens.