Rash

rash, nonspecific term for an eruption of the skin. It may result from skin allergy, skin irritation, or skin disease, or it may be a symptom of a systemic disease like measles, smallpox, or scarlet fever. A rash may appear as discolored spots or a general redness, or as blisters or pustules, either flat or raised above the surface of the skin. The rash may cause skin irritation—itching, tingling, burning, or pain—or it may not cause any discomfort. The appearance and distribution of a rash are often important factors for consideration in diagnosing a particular disease.

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rash

Pathol any skin eruption

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rash [rash]

(medicine)

A lay term for nearly any skin eruption, but more commonly for acute inflammatory dermatoses.

(mining engineering)

Very impure coal, so mixed with waste material as to be unsalable.

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Rash 

an eruption on the skin or mucous membrane of man, the cause of which can be either external and internal. Rashes accompany skin and other types of diseases. The external causes can be physical or chemical, while internal causes include diseases of the nervous and hemopoietic systems, metabolic disorders and functional disorders of certain organs (digestion, endocrine glands), infectious diseases (measles, scarlet fever), and allergic reactions (urticaria). Rashes may be primary or secondary. Primary rashes appear on previously normal skin or mucous membrane (spots, wheals, vesicles, pustules, tubercles). Secondary rashes appear as a further development of primary elements (pigmentation, scales, crusts, abrasions, ulcers, fissures, scars). The location, number, combination, color, shape, depth, and duration of the eruptions are helpful in diagnosing the disease.