Hyper-pigmentation and Hypo-pigmentation Disorders

Dermatology flashcards covering the characteristics, genetic patterns, and clinical associations of hyper-pigmentation and hypo-pigmentation disorders.

Freckles (Ephelides)

A hyper-pigmentation disorder characterized by increased melanocyte activity; associated with Xeroderma Pigmentosum and NAME syn.

Lentigines

A hyper-pigmentation disorder characterized by an increased number ($\uparrow \text{No.}$) of melanocytes; associated with Peutz Jegher syndrome.

Melasma

Pigmentation associated with pregnancy (Chloasma), thyroid disease, and Chickungunya.

CHIK sign

A clinical sign of pigmentation associated with Chickungunya.

Epidermal Pigmentation

Characteristically brown and appears enhanced ($++$) under a Wood's Lamp.

Dermal Pigmentation

Characteristically blue/slate grey and demonstrates the Tyndall effect.

Albinism

A congenital, Autosomal Recessive ($\text{AR}$) hypo-pigmentation disorder characterized by a lack of Tyrosinase ($\text{Tyrosinase O}$).

Nevus Depigmentosus

A congenital, non-progressive hypo-pigmentation disorder involving defective melanin distribution ($\text{Melanin distribution X}$), featuring satellites and feathery margins.

Nevus Anemicus

A hypo-pigmentation disorder caused by localized vasoconstriction.

Piebaldism

An Autosomal Dominant ($\text{AD}$) disorder involving the $\text{C-KIT}$ gene, characterized by "Islands of Sparing" and a white forelock.

Wardenberg syndrome

An Autosomal Dominant ($\text{AD}$) disorder involving the $\text{PAX-3}$ gene, characterized by heterochromia and a white forelock.

NCC Migration Defect

A defect resulting in no melanocytes, associated with syndromes like Wardenberg syndrome and Hypomelanosis of Ito.

Becker's Nevus

A type of hyper-pigmentation disorder.

Mongolian Spots

A type of hyper-pigmentation disorder.

Nevus of Ota

A type of hyper-pigmentation disorder.

Nevus of Ito

A type of hyper-pigmentation disorder.

Hypomelanosis of Ito

A hypo-pigmentation disorder listed alongside conditions involving neural crest cell migration defects.