Macule

Sinonimai

Macule, patch

Definition/Description

A flat, non-palpable, localized change in color of skin. Usually sharp borders
If larger than 1 cm: patch
Colors: red, brown, black, white, blue, yellow
Size: several millimeters

Special

Petechia (punctate bleeding into skin), purpura (small areas of bleeding), hematoma (larger areas of bleeding), deposition of pigmented material of different origin

Localization

Can appear anywhere on skin; for example macular exanthem
On mucosa: enanthem

Eiga

May develop into hive or a papule
May over time develop additional scaling
Often associated with papules, vesicles and pustules

Comment / Explanation

Large red patch = erythema
Erythroderma (generalized redness, often infiltrated)
Flush (acute transient facial erythema)

Typical Dermatoses

Drug induced eruption, macular lentigo, viral exanthema, vitiligo, pytiriasis versicolor

Pathophysiology

Vascular dilation, either because of aberrant vessels or inflammatory mediators (red): endogenous or exogenous pigment, for example melanin (brown-black, blue-gray), hemoglobulin (red-blue), hemosiderin (brown) lipids (yellow), loss of pigment (white) , external deposition of foreign body material (trauma, tattoo)

1.1 Macule