Introduction
Angioneurotic edema (ANE) is a major cause of mortality and morbidity rates worldwide. This condition's lifetime prevalence is around 25 % in the United States. It indicates that in the United States alone, more than one million emergency visits for angioneurotic attack exists every year. Failure to manage the respiratory airway difficulty caused due to laryngeal edema in an angioneurotic edema attack results in life-threatening consequences.
What Is Angioneurotic Edema?
Angioneurotic edema is a soft, painless swelling, usually non-itchy, that affects regions like the lips, tongue, and cheeks. ANE is a rapid reaction that increases in intensity over time. If the swelling spreads to the larynx or the voice box, the affected patient starts developing severe respiratory difficulties. This necessitates emergency treatment because of the serious reaction and intense swelling it produces.
What Causes Angioneurotic Edema?
The most common causes of angioedema are:
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Allergies - Any particular allergen or intolerable substances can cause an allergic angioedema reaction in an individual.
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Stings - Either bee or wasp stings.
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Drug-Induced - A drug-induced angioneurotic edema happens when individuals cannot tolerate certain medications or injections. The medications include angiotensinogen converting enzymes inhibitor drugs (ACEI), angiotensin II antagonist drugs, non-steroidal anti-inflammatory drugs (NSAIDs), selective serotonin reuptake inhibitors (SSRIs), oral contraceptive pills (OCPs) and proton pump inhibitors (PPIs). Even though these are common drugs prescribed with safety precautions by healthcare providers, allergic reactions have been observed when there is a sensitization to a particular drug or allergen. If an allergic episode happens, these medications may require sensitivity testing to avoid future episodes or relapse. Global reports of vaccine allergies in certain predisposed or sensitized individuals are also not uncommon in drug-induced ANE.
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Allergy to Certain Foods - Allergic reactions can be caused in individuals who are averse to seafood like shellfish or other food products like nuts and eggs.
What Are the Types of Angioneurotic Edema?
Angioneurotic edema is classified mainly into two categories :
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Nonallergic Angioneurotic Edema - This mainly results from hereditary causes. Idiopathic causes or environmental factors can also trigger it, especially when an individual faces intolerable allergens. Examples of hereditary causes are C1-esterase-inhibitor deficiency (HANE) and the acquired form (AANE). Type 1 and 2 hereditary ANE are autosomal dominant disorders because of gene mutations in the encoding genes for the C1-inhibitor.
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Allergic Angioneurotic Edema - Most of the angioneurotic edema reactions, approximately around 90 percent, are due to allergic reactions. Angioedema usually gets triggered within a few minutes after exposure to the allergen. Environmental or iatrogenic factors which can trigger a reaction include
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Viral infection.
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Undue exposure to heat or extreme cold.
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During pregnancy.
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Minor trauma situations (such as tongue piercing or tattoo).
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Mental or psychogenic stress.
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Ingestion of certain foods usually triggers allergic reactions.
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Allergic angioneurotic edema is also easily caused or precipitated in individuals with a low immune defense system, like those having chronic illnesses like lymphoproliferative disorders, cancers, autoimmune diseases, and infections.
What Are the Oral and Systemic Manifestations Seen in an Angioneurotic Edema?
The main clinical feature of angioneurotic edema is swelling of distensible tissues (tissues that can be stretched) like the eyes, face, mouth, lips, throat, extremities, or genitalia. Other systemic symptoms include:
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Vomiting.
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Colicky abdominal pain (cramp-like pain that comes and goes).
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Abdominal distention (swelling of the abdominal area) caused by obstruction of the intestine and submucosal edema of the bowel wall.
The oral feature of ANE includes swelling of the tongue and uvula region.
How Can an Angioneurotic Edema Be Diagnosed?
A confirmatory diagnosis has to be obtained before beginning the treatment plan. It is done by determining the potential allergen behind the reaction or detecting any underlying condition causing angioedema in the individual. Angioneurotic edema is diagnosed by physical examinations or a few other tests, which include-
Physical Examination -
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The healthcare provider can directly visualize an ANE patient's uvular or tongue swelling. However, some clinicians recommend laryngoscopy to assess the vocal cords.
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In allergic ANE attacks, itchy urticaria occurs. Skin rashes appear as red, swollen bumps over the trunk and limbs.
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Non-pitting edema is seen in the extremities of patients. Non-pitting edema is soft tissue swelling formed from the accumulation of extra fluid.
Cutaneous Tests - Sensitivity tests, such as prick test is performed in a clinical or hospital setting. In this test, to check for a reaction, the skin is pricked with a small amount of the suspected allergen.
What Are the Complications Associated With an Angioneurotic Edema?
The complications that arise with angioedema are mainly based on the oral manifestations it produces in a short time. These allergic reactions include:
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Tongue swelling.
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Swelling that extends to the larynx and the trachea (the voicebox or the windpipe).
Both of these swellings impact the normal respiratory pathway by causing airway obstruction. If a timely diagnosis or emergency management is not made for the affected patient, this obstruction can eventually lead to death.
How Is Angioneurotic Edema Managed?
For emergency management of an angioneurotic edema attack, a multidisciplinary array of healthcare specialists is required. While managing patients with angioneurotic edema attack, the preliminary emergency measure made by healthcare providers mainly includes relieving the respiratory tract obstruction using advanced airway equipment. A surgical airway or tracheotomy is established in patients with advanced bouts of glottic (middle part of the larynx) or supraglottic (upper part of the larynx) swelling. The swellings in the glottic region make it difficult for the healthcare provider to intubate the patient orally. So, the surgical establishment of the airway is done in such severity.
Conclusion
Angioneurotic edema is a serious condition that aggravates due to allergens within a short period. In an acute edema case, swellings start to develop in parts of the oral cavity and face within two hours of exposure to an allergen. Once the swelling begins in the tongue or neck, it extends down to the larynx, causing a respiratory airway obstruction. In an angioneurotic edema attack, adequate airway establishment is crucial in sustaining the patient's life. Emergency management, therefore, requires high-quality interdisciplinary and interprofessional collaborations to improve patient outcomes.
