flexural surface
Pertaining to the skin surface overlying muscles that flex joints, such as the biceps.
fluctuant
Movable and compressible.
follicular
1. Pertaining to a follicular distribution: A regular pattern following the distribution of hair follicles.
2. Pertaining to a follicular localization: Pertaining to the hair follicles.
fragile
Easily broken.
friable
Easily crumbled.
furuncle
A follicle-centered nodule caused by a suppurative infection characterized by pain, redness,and potentially visible pus. Usually greater than 1 cm in diameter.

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G
gangrene
Necrotic, usually black tissue, resulting from obstruction, diminution, or loss of blood supply. Gangrene may be wet or dry.
generalized
Widespread, affecting many body regions.
geographic
Resembling the outlines of a map.
geometric
Geometric forms, e.g., circles or angular lines.
glaborous areas
Smooth skin devoid of terminal hairs.
greasy scale
Yellow-brown scale.
grouped
Clustered.
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gumma
A soft nodule or small tumor often having an ulcerated surface. Historically gumma has been used to describe the lesions of tertiary syphilis and tuberculosis.
guttate
Drop-like.
gyrate
Arranged in rings or convolutions.
H
half-and-half nail
Color change in the nail bed with distal portion red-brown and the proximal aspect paler white. Most frequently seen in chronic renal disease.
halo
A zone surrounding a central lesion, area, or object.
hematoma
A collection of extravasated blood that is relatively or completely confined within a space. The blood is usually clotted (or partly clotted), and depending on time may manifest various degrees of organization and color.
herpetiform
Resembling the clusters or groups of lesions seen in herpes infections.
horn
An abnormally keratinized cutaneous projection that is taller than it is broad.

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hyperpigmented
Darkening of the skin due to increased melanin.
hyponychium
The hyponychium marks the anatomic area between the nail bed and the distal groove, where the nail plate detaches from the dorsal digit.
hypopigmented
Decreased skin pigmentation.
hystrix-like scale
Scale that appears as little horns. Porcupine-like.