acquired angioedema

Acquired Angioedema: A Rare Condition

Acquired angioedema (AAE) is a rare and potentially life-threatening condition characterized by recurring episodes of non-pitting edema, which is swelling that does not leave an indentation when pressed. This condition affects various parts of the body, including the face, lips, tongue, limbs, and genitals.

Key Features

• Recurring Episodes: AAE is marked by recurrent episodes of swelling, which can occur anywhere on the body.
• Non-Pitting Edema: The swelling does not leave an indentation when pressed, distinguishing it from other types of edema.
• Asymmetric Swelling: The swelling typically affects one side of the body or a specific area.

Causes and Associations

• C1 Inhibitor Deficiency: AAE is often caused by a deficiency or malfunction of complement 1 (C1) inhibitor, which plays a crucial role in regulating the classical pathway of human complement.
• Other Illnesses: Acquired angioedema may be associated with other conditions, such as cancer or autoimmune disorders.

Symptoms and Complications

• Swelling and Pain: The swelling can cause significant pain and discomfort.
• Abdominal Pain: In some cases, AAE can lead to abdominal pain due to the accumulation of fluid in the subcutaneous tissue.
• Respiratory Distress: Severe episodes of angioedema can lead to respiratory distress or failure.

References

1. Acquired angioedema (AAE) is characterized by acquired deficiency of C1 inhibitor (C1-INH), hyperactivation of the classical pathway of human complement and... [1]
2. Clinically, angioedema caused by an acquired deficiency of C1-inhibitor is indistinguishable from hereditary angio-edema (HAE). However, the condition usually... [4]
3. Hereditary angioedema and acquired angioedema due to C1 inhibitor deficiency are caused by deficiency or dysfunction of complement 1 (C1) inhibitor, ... [6]

Acquired Angioedema Signs and Symptoms

Acquired angioedema is a condition characterized by recurring episodes of swelling, which can be severe and potentially life-threatening. The signs and symptoms of acquired angioedema include:

• Swollen skin: Swelling develops below the skin's surface, causing the affected area to feel firm and thick.
• Puffy face: The face, especially around the eyes, cheeks, or lips, may become swollen and puffy.
• Digestive problems: Some people may experience digestive issues, such as stomach upset or intestinal swelling.
• Mild pain and warmth: The affected areas may feel mildly painful and warm to the touch.

Triggers

Acquired angioedema episodes can be triggered by various factors, including:

• Mild trauma: Dental work, tongue piercing, or other minor injuries
• Viral illness: Certain viral infections can trigger an episode
• Cold exposure: Exposure to cold temperatures may contribute to swelling
• Pregnancy: Hormonal changes during pregnancy can lead to acquired angioedema episodes
• Certain foods: Food allergy reactions can cause severe symptoms, including swelling

Symptom Duration

Acquired angioedema episodes typically last from two to five days and can recur at unpredictable intervals.

References:

[1] (Context 2) - Angioedema recurs at unpredictable intervals, lasts from two to five days and presents with edema of the skin (face, limbs, genitals), severe ...

[3] (Context 3) - Swelling episodes may have various triggers, such as mild trauma (such as dental work), viral illness, cold exposure, pregnancy, certain foods, or emotional ...

[5] (Context 5) - Triggers · Mild trauma (eg, dental work, tongue piercing) · Viral illness · Cold exposure · Pregnancy · Estrogen · Ingestion of certain foods.

[8] (Context 8) - Symptoms of angioedema. The main sign of angioedema is swelling that develops below the skin's surface. · Swollen skin. The swelling is caused by ...

[9] (Context 9) - Welts that form in minutes to hours · Swelling, especially around the eyes, cheeks or lips · Mild pain and warmth in the affected areas ...

Acquired angioedema (AAE) can be diagnosed through various diagnostic tests, which help confirm the condition and rule out other potential causes.

Laboratory Testing

• Complete blood cell count with differential: This test is recommended for all AAE patients to assess their overall health and identify any underlying conditions. [7]
• Measurement of C4 concentrations: Low levels of C4 can indicate AAE, as it is decreased both during and in between clinical flares. [5]
• Quantitative and functional analysis of C1-INH: This test helps diagnose AAE by measuring the levels and function of the C1 inhibitor protein. [6]

Complement Tests

• Determination of C1q levels: Reduced levels of C1q are a hallmark of AAE, as it is decreased in 70% of patients with this condition. If C1q is reduced, diagnosis of AAE can be confirmed. [8]
• Angiotensin-converting enzyme (ACE) inhibitor discontinuation test: This test involves measuring complement levels after discontinuing ACE inhibitors to diagnose acquired angioedema related to these medications. [9]

Other Tests

• Complete physical exam: A thorough physical examination is essential to assess the patient's overall health and identify any signs or symptoms of AAE.
• Urinalysis: This test may be performed to rule out other conditions that can cause similar symptoms.

It's worth noting that genetic testing can also confirm a diagnosis of acquired angioedema by identifying the disease-causing mutation(s) in the patient. [4] However, this is typically not the first line of diagnostic tests and is usually reserved for cases where the diagnosis is still unclear after other tests have been performed.

References: [4] Dec 1, 2023 — A diagnosis of HAE can be confirmed by genetic testing to identify the disease-causing mutation(s) a patient may be carrying. HAE types 1 and 2 ... [5] May 20, 2020 — Screening is conducted by determining the C4 level, which is decreased both during and in between clinical flares. If the C4 level is normal ... [6] Diagnosis relies on clinical findings, measurement of C4 concentrations and on quantitative and functional analysis of C1-INH. C1q levels are low in patients ... [7] by M Cicardi · 2010 · Cited by 231 — In addition to complete physical exam, we suggest that all patients have laboratory testing for complete blood cell count with differential ... [8] by M Cicardi · 2010 · Cited by 232 — This testing includes determination of C1q which is reduced in 70% of patients with AAE and is normal in HAE. If C1q is reduced, diagnosis of AAE can be ... [9] by Z Balla · 2021 · Cited by 23 — Acquired angioedema related to angiotensin-converting enzyme inhibitors may be diagnosed when complement tests at the discontinuation of angiotensin-converting ...

Treatment Options for Acquired Angioedema

Acquired angioedema can be effectively managed with various drug treatments, which aim to alleviate symptoms and prevent future episodes.

• Antifibrinolytic agents: These medications, such as tranexamic acid, have been shown to provide somewhat better results in preventing attacks of acquired angioedema [2][3]. They work by inhibiting the breakdown of fibrin, a protein involved in blood clotting.
• Attenuated androgens: Androgens, like danazol, may be beneficial in treating acquired angioedema type I. One study reported effective treatment of 75% of patients [6].
• C1 inhibitor synthesis: This treatment involves synthesizing the C1 inhibitor protein, which is deficient in individuals with acquired angioedema. While it may be less effective for the acquired form of angioedema, short-term prophylaxis can be achieved using this method [4].
• Rituximab and cyclophosphamide: This combination therapy has been shown to be a partly effective treatment in most patients with acquired angioedema [5].

Important Considerations

It is essential to note that the effectiveness of these treatments may vary depending on individual circumstances. Intensive support, including intravenous fluids and intubation, may be necessary for severe cases [1]. Consultation with a healthcare professional is crucial to determine the best course of treatment.

References:

[1] May 20, 2020 — Depending on the symptoms and the site of the angioedema, intensive support may be necessary, including intravenous fluids. Intubation may be ...

[2] by M Cicardi · 2010 · Cited by 231 — Angioedema prophylaxis is performed using antifibrinolytic agents and attenuated androgens with antifibrinolytic agents providing somewhat better results.

[3] by M Cicardi · 2010 · Cited by 232 — Angioedema prophylaxis is performed using antifibrinolytic agents and attenuated androgens with antifibrinolytic agents providing somewhat better results.

[4] C1 inhibitor synthesis. This treatment may be less effective for the acquired form of angioedema. Short-term prophylaxis.

[5] by RS Petersen · Cited by 1 — Rituximab, alone or combined with cyclophosphamide, has been shown to be a partly effective treatment in most patients.

[6] May 20, 2020 — Androgens, such as danazol, may be beneficial in acquired angioedema type I, with one study reporting effective treatment of 23 (75%) of 31 ...

Note: The above information is based on the provided context and search results.

Differential Diagnosis of Acquired Angioedema

Acquired angioedema (AAE) is a rare and potentially life-threatening condition characterized by recurrent episodes of non-pitting edema, often accompanied by urticaria or wheals. The differential diagnosis for AAE includes several conditions that can present with similar symptoms.

Conditions to Consider:

• Allergic contact dermatitis: This skin condition can cause localized swelling, redness, and itching, which may be mistaken for angioedema.
• Connective tissue disease: Conditions such as lupus or scleroderma can lead to widespread edema, including angioedema-like symptoms.
• Endocrine disorders: Hormonal imbalances, particularly those affecting the thyroid gland, can cause swelling and edema.
• ACE inhibitor-induced angioedema: Certain medications, like ACE inhibitors, can trigger episodes of angioedema in susceptible individuals.

Key Diagnostic Features:

• Low C1-inhibitor concentration and function: AAE is characterized by a deficiency or dysfunction of the C1-inhibitor protein.
• Low complement factor 4 (C4): Reduced levels of C4 are often observed in patients with AAE.
• Recurrent episodes of swelling: Patients with AAE typically experience repeated episodes of angioedema, which can be triggered by various factors.

References:

• [4] Acquired angioedema (AAE) is characterized by acquired deficiency of C1 inhibitor (C1-INH), hyperactivation of the classical pathway of complement, and low levels of complement factor 4 (C4).
• [5] The diagnosis of acquired angio-edema is based on a (very) low level of C1-inhibitor concentration and its function and (usually) low complement factor 4 (C4).
• [6] A thorough medical history is needed to reveal potential allergen exposure, which can trigger episodes of angioedema.
• [8] The differential diagnosis for swelling includes all types of AE as well as urticaria, anaphylaxis, hydrostatic edema, oncotic edema, and less common syndromes.