Acute Urticaria Clinical Presentation

Updated: Sep 13, 2016
  • Author: Henry K Wong, MD, PhD; Chief Editor: Michael A Kaliner, MD  more...
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Presentation

History

Pruritus (itching) and rash are the primary manifestations of urticaria, and permanent hyperpigmentation or hypopigmentation is rare.

Lesions commonly last 20 minutes to 3 hours, disappear, and then reappear in other skin areas. An entire episode of urticaria often lasts 24-48 hours; individual lesions usually fade within 24 hours or so, but new lesions may be developing continuously. Rarely, acute urticaria can last 3-6 weeks. [29] Scars do not develop.

With delayed pressure urticaria, lesions may last as long as 48 hours. The lesions of urticarial vasculitis, which are palpable and purpuric, may last for several days or more and may lead to residual hyperpigmented changes. [30]

Typical lesions described by patients are edematous pink or red wheals of variable size and shape that are pruritic. [31] The lesions are often described as welts or hives, including pressure-induced hives, which can occur with elastic or tight clothing, as shown in the images below. [32] Patients may report a painful or burning sensation; such lesions are often associated with angioedema. [33] Pruritus of nonlesional skin may also occur.

Photograph of dermographism. Photograph of dermographism.
Pressure urticaria (dermatographia) developed afte Pressure urticaria (dermatographia) developed after strokes.
Acute urticaria associated with dermatographism. Acute urticaria associated with dermatographism.

Determining whether the lesions have an allergic (IgE) or nonallergic (non-IgE) basis is helpful in the management of the patient. A complete thorough medical and travel history is important to provide clues to urticaria resulting from a new infectious or medical problem. Questions asked to determine possible allergic and nonallergic causes include the following:

  • Are the hives associated with any foods? Have any new foods been added to the diet?
  • Is the patient taking any regular medications, or have any new medicines been started? In particular, ask about aspirin, NSAIDs, antibiotics, over-the-counter (OTC) medications, herbs, and supplements.
  • Does the patient have any recent or chronic infections?
  • Are the hives caused by any physical stimuli (eg, heat, cold, pressure, vibration)?
  • Does the patient have any chronic medical conditions?
  • Is the urticaria associated with any substances that are inhaled or come in contact with the skin (which may occur in an occupational setting)?
  • Is the urticaria associated with insect bites or stings?
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Physical Examination

If any features of anaphylaxis (eg, hypotension, respiratory distress, stridor, gastrointestinal distress, swallowing problems, joint swelling, joint pain) are present, immediate medical intervention should occur.

Assess for any features of angioedema (deep tissue or submucosal edema). [34] Angioedema appears as swellings of the tissues, with indistinct borders around the eyelids and lips. Swellings may also appear on the face, trunk, genitalia, and extremities. The face, hands, and feet are involved in 85% of patients. As many as 50% of children who have urticaria exhibit angioedema with swelling of the hands and feet. Hereditary angioedema (C1 inhibitor deficiency) accounts for only 0.4% of cases of angioedema but is associated with a high mortality rate.

Lesions of urticaria can be polymorphic and vary from several millimeters to large, continuous edematous plaques that have smooth surfaces with polycyclic curved borders. The lesions do not have scales but show an intense erythema in the newest areas, with a trailing clearing region in older areas. The central clearing can cause a target configuration in expanding plaques. The advancing border shows a discrete edge followed by a faint, trailing, diffuse border.

Look for any atypical skin lesions. Lesions that are purpuric, nonblanchable, and palpable are characteristic of urticarial vasculitis. These lesions may leave residual pigmented changes. Tiny pinpoint hives are characteristic of cholinergic urticaria. [35]

Edema can be observed by slightly stretching the skin to demonstrate whitish centers. Occasionally, large annular urticarial lesions as large as 30 cm in diameter with polycystic borders are observed.

Examine for dermographism, as it is often observed in conjunction with urticaria. Itching, erythema, and a raised wheal occur in areas that are scratched or stroked with a blunt object, such as a tongue blade. [36] The examiner can use the end of a tongue blade or similar blunt object to scratch the patient's skin and observe the area over the next 5-15 minutes for the development of whealing with erythema, as shown in the following image.

Photograph of dermographism. Photograph of dermographism.

The remainder of the physical examination should be used to investigate any suspicions that were raised by the history.

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Staging

According to a study, the cutaneous biopsy of urticaria lesions may be divided into the following categories, as the response to treatment could be different:

  • Class 1 - A mixture of perivascular dermal inflammatory infiltrates composed of lymphocytes, monocytes, and neutrophils, eosinophils, or both
  • Class 2 - Inflammatory infiltrate chiefly composed of neutrophils [37]
  • Class 3 - Inflammatory infiltrate mainly composed of eosinophils
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