Urticaria [Hives]
Urticaria [Hives]: Excerpt from Nursing: Interpreting Signs and Symptoms
Urticaria 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.
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.
Action stat!
In an acute case of urticaria, quickly evaluate respiratory status, and take the patient's 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. Clear and maintain the airway, give oxygen as needed, and institute cardiac monitoring. Have resuscitation equipment at hand, and be prepared to begin cardiopulmonary resuscitation. Endotracheal intubation or a tracheostomy may be required.
History and physical examination
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 or detergents? 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.
Next, assess respiratory status. Inspect the chest for sternal retractions and accessory muscle use. Auscultate and percuss the chest. Assess cardiac status. Obtain vital signs and pulse oximetry and begin cardiac monitoring. Assess all skin surfaces.
Medical causes
Anaphylaxis.Anaphylaxis—an acute allergic reaction—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.With hereditary angioedema, 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 Lyme disease, urticaria may result from the characteristic skin lesion (erythema chronicum migrans). Later effects include constant malaise and fatigue, intermittent headache, fever, chills, lymphadenopathy, neurologic and cardiac abnormalities, and arthritis.
Other causes
Drugs.Drugs that can produce urticaria include aspirin, codeine, dextrans, immune serums, insulin, morphine, penicillin, quinine, sulfonamides, and vaccines.
Radiographic contrast medium.Radiographic contrast medium, especially when administered I.V., commonly produces urticaria.
Nursing considerations
▪ Apply a bland skin emollient or one containing menthol and phenol to the patient's skin.
▪ Administer an antihistamine, a systemic corticosteroid or, if stress is a suspected contributing factor, a tranquilizer, as ordered.
▪ Provide tepid baths and cool compresses to enhance vasoconstriction and decrease pruritus.
▪ Administer oxygen and monitor respiratory status.
Patient teaching
▪ Explain the underlying disorder and treatment plan.
▪ Teach the patient to avoid the causative stimulus, if identified.
▪ Emphasize the importance of wearing medical identification for allergies.
▪ Explain signs and symptoms that require prompt medical attention.
▪ Stress ways to avoid anaphylaxis.
▪ Teach the patient and his family how to use an anaphylaxis kit.
Book Source Details
- Book Title: Nursing: Interpreting Signs and Symptoms
- Author(s): Springhouse
- Year of Publication: 2007
- Copyright Details: Nursing: Interpreting Signs and Symptoms, Copyright © 2007 Lippincott Williams & Wilkins.
More About Insect sting allergies
More Medical Textbooks Online about Insect sting allergies
Review other book chapters online related to Insect sting allergies:
Medical Books Excerpts
- Urticaria
- "In A Page: Pediatric Signs and Symptoms" (2007)
- [ read ]
- Urticaria
- "A Pocket Manual of Differential Diagnosis" (1999)
- [ read ]
- Anaphylaxis
- "Professional Guide to Diseases (Eighth Edition)" (2005)
- [ 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: Mammalian Bites (The 5-Minute Pediatric Consult)
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:
