A handbook of the theory and practice of medicine / by Frederick T. Roberts.

  • Frederick Thomas Roberts
Date:
1883
Catalogue details

Licence: Public Domain Mark

Credit: A handbook of the theory and practice of medicine / by Frederick T. Roberts. Source: Wellcome Collection.

    954/1006 (page 934)
    structural change, so long as there is not very marked elevation or depres- sion. Tiny points are calledpimcke, and widely diffused stains or blushes dis- coloratiom. Maciikc may be caused by simple staining or chemical changes, for example, from iodine or silver nitrate ; by extravasations of blood, as in purpura and scurvy ; by increased deposition of pigment as in one phase of leprosy, in Addison's disease, in ephelides or freckles, in chloasma uterinum et gravidarum; by irregular deposition (both removal and depo- sition going on side by side) as in leucoderma; by the growth of vegetable parasites in the skin, as in tinea versicolor; by new growths or chronic in- flammations of the corium, as in naevi or morphaea ; lastly, by slight con- gestions or superficial inflammations, as in erythema, and the erythematous phases of lupus, syphilis, and lepros}^. A papule or pimple is a solid eleva- tion of the skin, whatever may be its cause, whether from congestion about one or more follicles, as in miliaria; the accumulation of exudation from inflammation, as in eczema papulosum ; new growth, as in lupus; over- growth of the epidermis, as in psoriasis and some warts; new growths of blood- or lymph-vessels ; or blocking or stuffing of the ducts or glands by epithelial exuvife or secretion, as in comedones or milium. Papules vary in size from a pin's head (miliary papules) to a sixpence or more, as in syphilis ; and they may be rounded (papular erythema), or quadrangular (lichen planus), conical, dome-shaped, disc-like (nummular), or flat (len- ticular). When the morbid process giving rise to the papule extends deeply, the term tubercle or nodule is usually applied, and hence the ex- pressions tubercular lupus, leprosy, and syphilis ; but it is not intended to convey the idea of any association with tuberculosis. Phymata or tuinours are solid formations in the skin exceeding a walnut in size, as in erythema nodosum and fibroma molluscum. They may be prominent or deep set, sessile or pedunculate. Pomphi or wheals are rounded or oval evanescent swellings, accompanied by heat and tingling, due to the sudden and tem- porary dilatation of a bunch of vessels under nervous influence, causing traiisient acute hyperasmia and oedema of localized areas. They are typically seen in the effects of nettle-stings. The oedema is generally sufficient in the central parts to obscure the pink colour resulting from the hyperaemia, so that a wheal usually presents a white centre and a pink halo. Wheals may be of all sizes, from a split pea upwards, and some- times cover very large and irregular tracts by confluence. Vesicles are small dome-shaped or acuminate elevations of the skin, formed by the accumulation of fluid, or by the dilatation and projection of lymph- (varicose lymphatics) or blood- radicles (vesicular degeneration of ntevi). The accumulated fluid is frequently inflammatory, as in eczema and herpes, and exudes from the blood-vessels to collect within and between the rele cells, or between the cuticle and rete (pemphigus). These in- flammatory vesicles are often compound, and quickly rupture or coflapse, and as they are frequently only an advanced stage of the inflammatory papule, so in their turn they may give place to the pustule. In sudamina the sweat passes out of the duct, to accumulate between the strata of the cuticle. The name bulla or bleb is applied when the collection of fluid is large, for example, greater than a split pea. Bulte are formed as vesicles are, and are specially characteristic of pemphigus, but may occur less prominently in a number of other affections, such as erysipelas, scabies, erythema, and lierpes iris, syphilis and leprosy, and, lastly, by the coalescence of vesicles in dysidrosis. Pustules are circumscribed inflammatory elevations of the surface of moderate size, formed by the collection of ]jus in the skin. They usually have an inflamed areola, and frequently end in ulceration and scarring. A