Dermatologist Certificate Trivia 5

Question 1

Which structure within the hair follicle is responsible for generating the hair shaft and is often called the 'hair matrix'?

Accepted Answer

The bulb at the base of the follicle

Answer

The hair bulb contains rapidly dividing matrix cells that differentiate and keratinize to form the hair shaft, driven by signals from the dermal papilla.

Question 2

What dermatological tool, invented in the 1990s, allows in vivo visualization of the epidermis and dermal-epidermal junction without biopsy?

Accepted Answer

Dermoscopy (dermatoscopy)

Answer

Dermoscopy uses polarized or contact oil lens illumination to visualize subsurface skin structures, improving melanoma detection accuracy.

Question 3

Which autoimmune blistering disease is characterized by IgG antibodies against desmoglein 1 and 3, affecting the epidermis?

Accepted Answer

Pemphigus vulgaris

Answer

Pemphigus vulgaris features IgG autoantibodies against desmoglein 3 (mucosal) and desmoglein 1 (cutaneous), causing acantholysis and suprabasal blisters.

Question 4

The term 'lichenification' refers to which morphological skin change caused by chronic rubbing or scratching?

Accepted Answer

Thickened, exaggerated skin markings with a leathery texture

Answer

Lichenification describes thickened, leathery skin with accentuated surface markings, resulting from prolonged rubbing or scratching in conditions like atopic dermatitis.

Question 5

What is the primary cell type responsible for the inflammatory response in contact dermatitis?

Accepted Answer

CD4+ T lymphocytes (Th1/Th2 cells)

Answer

Allergic contact dermatitis is a Type IV (delayed-type) hypersensitivity reaction mediated by sensitized CD4+ T lymphocytes responding to the hapten-carrier complex.

Dermatologist Certificate Practice Test

Dermatologist Certificate Practice Test

Dermatologist Certificate Trivia 5