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a vascular reaction of the skin marked by transient appearance of slightly elevated patches (wheals) that are redder or paler than the surrounding skin and often attended by severe itching; the cause may be certain foods, infection, or emotional stress. (See Atlas 2, Plate D.) Called also hives. adj., adj urtica´rial.
cold urticaria urticaria precipitated by cold air, water, or objects, occurring in two forms: In the autosomal dominant form, which is associated with fever, arthralgias, and leukocytosis, the lesions occur as erythematous, burning papules and macules. The more common acquired form is usually idiopathic and self-limited.
giant urticaria angioedema.
urticaria hemorrha´gica purpura with urticaria.
urticaria medicamento´sa that due to use of a drug.
papular urticaria (urticaria papulo´sa) an allergic reaction to the bite of various insects, with appearance of lesions that evolve into inflammatory, increasingly hard, red or brownish, persistent papules.
urticaria pigmento´sa the most common form of mastocytosis, occurring primarily in children, manifested as persistent pink to brown macules or soft plaques of various size; pruritus and urtication occur on stroking the lesions.
urticaria pigmentosa, juvenile urticaria pigmentosa present at birth or in the first few weeks of life, usually disappearing before puberty, taking the form of a single nodule or tumor or of a disseminated eruption of yellowish brown to yellowish red macules, plaques, or bullae.
solar urticaria a rare form produced by exposure to sunlight.
Etymology: L, urtica, nettle, papula, pimple
a form of skin eruption affecting mainly children and characterized by reddish macules on which papules develop.