Lesions vary in size, shape and distribution. They are called punctate when they occur in dots or points; miliary, when the size of a millet seed; guttate, when the size of a drop of water; lenticular, when the size of a small pea or bean; and nummular, when the size of a small coin. Regarding their shape, lesions are said to be accuminate, when pointed; plane, when flat; conic, when cone-shaped; and umbilicated when depressed in the center. Regarding their location, they are described as isolated, when far apart; discrete, when not joined; confluent, when coalescing; and aggregated, when close together.
Patch signifies a single group of lesions or a distinct area of disease. Patches are composed of one or more types of lesions, thus macules, papules, vesicules or pustules may exist alone in one patch or may all be present in the same area, or the transitional varieties such as the papulovesicular or vesicopustular may predominate. The form, location, and relative arrangement of patches as well as individual lesions are influenced in a large degree by the direction of the bundles of connective tissue fibers which form the “lines of cleavage” of the skin, and the consequent vascular distribution to the different parts. The vasomotor centers located in the cord, which preside over certain vascular districts, furthermore influence the distribution of eruptions. When patches are limited in extent, they are said to be circumscribed; when distributed over a larger and irregular area, diffuse; when disposed in circular form or in sections of a circle, circinate; when in the shape of rings, annulate; when they have the appearance of concentric rings, iris; when the circles or rings, which have coalesced, fade away at the points of contact, gyrate or figurate; when one or more portions of the patch advances and another, usually an older part clears, the condition is called serpiginous; or when a patch shows an abrupt edge or is well defined, it is called marginate.
Eruption is the descriptive term signifying the totality of the objective manifestation, hence it includes all lesions, groups, areas or patches considered as a whole, no matter where located on the surface. When an eruption covers the entire cutaneous surface, it is said to be universal; when distributed over the whole body, with areas of sound skin between, general; when irregularly scattered over the surface, disseminate; when limited to one or a few regions, localized; when occurring alike on both lateral halves of the body, symmetrical; when limited to one side of the body, unilateral; when consisting of one type of lesions, uniform; or when presenting more than one variety of primary lesions, multiform or polymorphous.
Usually the meaning of the qualifying terms, employed to describe the peculiarities of lesions, patches and eruptions as regards their shape, color, distribution, cause and other features, is easily understood. However, for the convenience of the reader, the following list, alphabetically arranged, with the meaning briefly outlined, is added. It might be said that these terms are mostly in the Latin form and the exact termination to be used must be governed by the associated word or words. The equivalent English adjectives will readily suggest themselves.
ABDOMINALIS. Located on the abdominal surface.
ACQUISITUS. Acquired as contrasted to inherited.
ACUMINATUS. Having a pointed apex.
ACUTUS. Of acute course.
ADULTORIUM. Occurring in adult years.
AESTIVALIS. Occurring in the season of summer.
AGRIUS. Angry in appearance or malignant in character.
ALBIDUS. Of whitish color.