ABD Pigmentary Disorders 2

Question 1

Generalized hyperpigmentation in Addison's disease (primary adrenal insufficiency) is caused by:

Accepted Answer

Excess ACTH cross-reacting with MC1R on melanocytes due to loss of cortisol feedback

Answer

Direct adrenal pigment deposition in the skin

Answer

Secondary hypercortisolism stimulating melanogenesis

Answer

Pineal gland secretion of alpha-MSH

Question 2

Long-term amiodarone therapy produces a distinctive skin discoloration described as:

Accepted Answer

Slate-gray to blue-gray from drug-lipofuscin complexes in dermal macrophages in sun-exposed areas

Answer

Brown-black from direct melanocyte stimulation

Answer

Yellow from lipid-drug complexes in the dermis

Answer

Red-brown from hemosiderin deposition

Question 3

Which combination of features best differentiates dermal melanocytosis (Mongolian spot) from non-accidental trauma (bruising) in an infant?

Accepted Answer

All of the above

Answer

Location on the lumbosacral area only

Answer

Blue-gray color stable over days without color evolution or associated edema

Answer

Presence at birth

Question 4

A halo nevus with a depigmented ring surrounding a central benign-appearing melanocytic nevus is best explained by:

Accepted Answer

Cytotoxic T-lymphocyte-mediated immune destruction of nevus melanocytes extending to surrounding normal melanocytes

Answer

Early superficial spreading melanoma replacing nevus cells

Answer

Traumatic depigmentation from repeated friction

Answer

Postinflammatory hypopigmentation from prior dermatitis

Question 5

Progressive macular hypomelanosis is distinguished from pityriasis versicolor by which Wood's lamp finding?

Accepted Answer

Folliculocentric red fluorescence in coalescing hypopigmented trunk macules

Answer

Brilliant blue-white fluorescence of hypopigmented patches

Answer

Yellow-green fluorescence throughout affected areas

Answer

No fluorescence, distinguishing it from pityriasis versicolor's yellow fluorescence

Question 6

Idiopathic guttate hypomelanosis is best described as:

Accepted Answer

Multiple discrete small porcelain-white macules on chronically sun-exposed extremities of middle-aged and older adults due to focal melanocyte loss

Answer

Autoimmune complete depigmentation in sun-exposed skin of young adults

Answer

Congenital hypopigmented macules with central clearing

Answer

Drug-induced melanocyte toxicity presenting on the legs

Question 7

For refractory dermal melasma in a Fitzpatrick skin type IV patient, which laser approach is preferred with the lowest risk of post-inflammatory hyperpigmentation?

Accepted Answer

Q-switched Nd:YAG 1064 nm at low fluence (toning protocol)

Answer

Ablative fractional CO2 laser at high energy

Answer

Pulsed dye laser 595 nm

Answer

KTP 532 nm laser targeting epidermal pigment