Urticaria
Urticaria: Excerpt from Signs & Symptoms: A 2-in-1 Reference for Nurses
Urticaria, also known as hives, is a vascular skin reaction characterized by the eruption of transient pruritic wheals — smooth, slightly elevated patches with well-defined erythematous margins and pale centers of various shapes and sizes. It’s produced by the local release of histamine or other vasoactive substances as part of a hypersensitivity reaction. (See Recognizing common skin lesions, pages 488 and 489.)
Acute urticaria evolves rapidly and usually has a detectable cause, commonly hypersensitivity to certain drugs, foods, insect bites, inhalants, or contactants; emotional stress; or environmental factors. Although individual lesions usually subside within 12 to 24 hours, new crops of lesions may erupt continuously, thus prolonging the attack.
Urticaria lasting longer than 6 weeks is classified as chronic. The lesions may recur for months or years, and the underlying cause is usually unknown. Occasionally, a diagnosis of psychogenic urticaria is made.
Angioedema, or giant urticaria, is characterized by the acute eruption of wheals involving the mucous membranes and, occasionally, the arms, legs, or genitals.
Emergency Actions
In an acute case of urticaria, quickly evaluate respiratory status and take vital signs. Ensure patent I.V. access if you note any respiratory difficulty or signs of impending anaphylactic shock. Also, as appropriate, give local epinephrine or apply ice to the affected site to decrease absorption through vasoconstriction. Maintain a patent airway, give oxygen as needed, and institute cardiac monitoring. Have resuscitation equipment at hand, and be prepared to begin cardiopulmonary resuscitation. Intubation or a tracheostomy may be required.
History
If the patient isn’t in distress, obtain a complete history. Does he have any known allergies? Does the urticaria follow a seasonal pattern? Do certain foods or drugs seem to aggravate it? Is there a relationship to physical exertion? Is the patient routinely exposed to chemicals on the job or at home? Has the patient recently changed or used new skin products? Obtain a detailed drug history, including prescription and over-the-counter drugs. Note any history of chronic or parasitic infection, skin disease, or a GI disorder.
Physical assessment
Obtain the patient’s vital signs. Perform a complete cardiopulmonary assessment, noting signs and symptoms of shock or respiratory distress. Finish your examination by assessing for urticaria in other areas because new crops may continue to appear.
Medical causes
Anaphylaxis
Anaphylaxis is marked by the rapid eruption of diffuse urticaria and angioedema, with wheals ranging from pinpoint to palm-size or larger. Lesions are usually pruritic and stinging; paresthesia commonly precedes their eruption. Other acute findings include profound anxiety; weakness; diaphoresis; sneezing; shortness of breath; profuse rhinorrhea; nasal congestion; dysphagia; and warm, moist skin.
Hereditary angioedema
Hereditary angioedema is an autosomal dominant disorder in which cutaneous involvement is manifested by nonpitting, nonpruritic edema of an extremity or the face. Respiratory mucosal involvement can produce life-threatening acute laryngeal edema.
Lyme disease
Although not diagnostic of this tick-borne disease, urticaria may result from the characteristic skin lesion (erythema chronicum migrans). Later effects of Lyme disease include constant malaise and fatigue, intermittent headache, fever, chills, lymphadenopathy, neurologic and cardiac abnormalities, and arthritis.
Other causes
Drugs
Many drugs can produce urticaria. Among the most common are aspirin, atropine, codeine, dextrans, immune serums, insulin, morphine, penicillin, quinine, sulfonamides, and vaccines. In addition, radiographic contrast medium commonly produces urticaria, especially when administered I.V.
Special considerations
To help relieve the patient’s discomfort, apply a bland skin emollient or one containing menthol and phenol. Expect to give an antihistamine, a systemic corticosteroid or, if stress is a suspected contributing factor, a tranquilizer. Tepid baths and cool compresses may also enhance vasoconstriction and decrease pruritus.
Pediatric pointers
Pediatric forms of urticaria include acute papular urticaria (usually after insect bites) and urticaria pigmentosa (rare). Hereditary angioedema may be causative.
Patient counseling
Explain the importance of wearing medical identification for allergies. Discuss the risks of delayed symptoms and the need to report any recurrence of dyspnea, urticaria, chest tightness, angioedema, or other symptoms. Teach the patient ways to prevent anaphylaxis, such as avoiding the causative food or drug. Tell him to carry an anaphylaxis kit containing epinephrine and an antihistamine and make sure he knows how to use it.
Pictures
Book Source Details
- Book Title: Signs & Symptoms: A 2-in-1 Reference for Nurses
- Author(s): Springhouse
- Year of Publication: 2007
- Copyright Details: Signs & Symptoms: A 2-in-1 Reference for Nurses, Copyright © 2007 Lippincott Williams & Wilkins.
More About Mastocytosis
More Medical Textbooks Online about Mastocytosis
Review other book chapters online related to Mastocytosis:
Medical Books Excerpts
- Urticaria
- "In A Page: Pediatric Signs and Symptoms" (2007)
- [ read ]
- Urticaria
- "A Pocket Manual of Differential Diagnosis" (1999)
- [ read ]
- Urticaria
- "The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter" (2000)
- [ read ]
- Urticaria
- "Alarming Signs and Symptoms: Lippincott Manual of Nursing Practice Series" (2007)
- [ read ]
- Urticaria
- "Signs & Symptoms: A 2-in-1 Reference for Nurses" (2007)
- [ read ]
Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
» Next page:
Urticaria [Hives] (Nursing: Interpreting Signs and Symptoms)
Rate This Website
What do you think about the features of this website?
Take our user survey and have your say:
Website User Survey
Medical Tools & Articles:
Next articles:
Tools & Services:
Medical Articles:
Forums & Message Boards
- Ask or answer a question at the Boards:
