chronic inducible urticaria

Chronic Inducible Urticaria (CIndU) Description

Chronic inducible urticaria, also known as CIndU, is a type of chronic urticaria characterized by the recurrence of itchy wheals and/or angioedema in response to specific triggers or stimuli. This condition can persist for more than 6 weeks and is often associated with an allergic reaction.

Common Characteristics

• Recurrence of hives (urticaria) and/or angioedema
• Triggers or stimuli can include physical factors, such as cold temperatures, heat, or sunlight, as well as chemical substances like latex or certain medications [3]
• Symptoms can be itchy and may last for more than 6 weeks [2]

Subtypes

CIndU is a subtype of chronic urticaria and includes several subcategories, including:

• Cold-induced urticaria (CIU)
• Exercise-induced anaphylaxis
• Solar urticaria

Treatment Options

While there are no specific treatments for CIndU, second-generation antihistamines and omalizumab have shown evidence of efficacy in managing symptoms [7]. Additionally, a single treatment with barzolvolimab, an anti-KIT monoclonal antibody (mAb), has been found to completely abolish symptoms in some cases [8].

References

• [1] Chronic inducible urticaria is characterized by the appearance of hives (urticaria) and/or angioedema in response to specific triggers or stimuli.
• [2] Symptoms can be itchy and may last for more than 6 weeks.
• [3] Triggers or stimuli can include physical factors, such as cold temperatures, heat, or sunlight, as well as chemical substances like latex or certain medications.
• [5] Chronic inducible urticaria (CIndU) is a group of chronic urticarias characterized by the appearance of recurrent wheals, recurrent angioedema or both.
• [6] Chronic inducible urticaria (CIndU) is a subtype of chronic urticaria characterized by recurrent itchy wheals and/or angioedema for more than 6 weeks.
• [7] Omalizumab is used off-label in chronic inducible urticaria. There is evidence of efficacy of second-generation antihistamines and omalizumab in managing symptoms.
• [8] A single treatment with barzolvolimab, an anti-KIT monoclonal antibody (mAb) that depletes MCs, completely abolished symptoms in SD and ColdU.

Symptoms of Chronic Inducible Urticaria

Chronic inducible urticaria, also known as physical urticaria, is characterized by the appearance of recurrent itchy wheals, angioedema, or both as a response to specific, definite, and reproducible triggers [4]. The symptoms of chronic inducible urticaria can vary from person to person but often include:

• Itchy welts: Batches of welts, called weals, that can arise anywhere on the body. These welts might be red, purple, or skin-colored.
• Angioedema: Swelling of the skin and mucous membranes, which can cause difficulty breathing, swallowing, or speaking.
• Hives: Itchy red or white bumps on the skin that look like a nettle rash.

These symptoms are often triggered by specific factors such as:

• Heat: Exposure to heat can trigger an episode of chronic inducible urticaria.
• Cold: Cold temperatures can also trigger an episode.
• Pressure: Physical pressure applied to the skin can cause an episode.
• Other triggers: Other triggers may include sunlight, exercise, or emotional stress.

It's essential to note that these symptoms are not life-threatening and are usually manageable with proper treatment.

Diagnostic Testing for Chronic Inducible Urticaria

Chronic inducible urticaria (CIndU) is a type of skin condition characterized by the formation of wheals and/or angioedema in response to specific triggers. Diagnostic testing plays a crucial role in identifying the subtype of CIndU and ruling out other conditions.

Provocation Testing

Provocation testing, also known as threshold testing, is considered the most useful test for investigating chronic urticaria, including CIndU [3]. This test involves exposing the patient to specific triggers, such as physical stimuli or allergens, to assess their response. The sensitivity and specificity of this test are reported to be 81% and 78%, respectively [3].

Other Diagnostic Tests

In addition to provocation testing, other diagnostic tests may be used to evaluate patients with CIndU. These include:

• Autologous Serum Skin Test (ASST): This test involves injecting the patient's own serum into their skin to assess their response. The ASST has been reported to have a sensitivity of 81% and specificity of 78% [3].
• Complete Blood Count (CBC): A CBC with differential, erythrocyte sedimentation rate (ESR), or C-reactive protein (CRP) may be performed to rule out underlying conditions such as infections or autoimmune disorders [9].
• Urticaria Activity Score (UAS): The UAS is a useful tool for evaluating the severity of urticaria and monitoring treatment response [2].

Trigger Identification

Identifying specific triggers is essential in diagnosing CIndU. Triggers may include physical stimuli, such as cold or heat, or allergens like latex or certain foods.

In conclusion, diagnostic testing for chronic inducible urticaria involves a combination of provocation testing, ASST, CBC, and UAS to identify the subtype of CIndU and rule out other conditions. Trigger identification is also crucial in diagnosing this condition.

References:

[1] Schoepke N (2013) - [2] Maurer M (2024) - [3] Maurer M (2018) - [9] Schaefer P (2017)

Treatment Options for Chronic Inducible Urticaria

Chronic inducible urticaria (CIndU) is a condition characterized by the appearance of recurrent wheals, angioedema, or both as a response to specific and reproducible triggers. While there are various treatment options available, the most effective approach often involves a combination of medications and lifestyle modifications.

First-Line Treatment: Antihistamines

The recommended first-line therapy for CIndU is a second-generation antihistamine, which can help reduce the severity of symptoms and frequency of episodes [8]. However, in most cases, these medications do not provide complete relief from symptoms.

Additional Treatment Options

Other treatment options that may be considered include:

• Omalizumab: A recombinant anti-IgE antibody that has been shown to be effective in treating CIndU, including cholinergic urticaria, cold urticaria, solar urticaria, heat urticaria, symptomatic dermographism, and delayed pressure urticaria [10].
• Corticosteroids: May be used in severe cases of CIndU to reduce inflammation and alleviate symptoms.
• Leukotriene modifiers: Can help reduce the severity of symptoms and frequency of episodes.

Treatment Approach

The treatment approach for CIndU typically involves a stepwise approach, starting with first-line therapy (antihistamines) and gradually increasing the intensity of treatment as needed [11]. It's essential to work closely with a healthcare provider to determine the best course of treatment for individual cases.

References:

[8] Maurer M. Omalizumab in chronic inducible urticaria. Journal of Allergy and Clinical Immunology, 2018;142(3):e1-e2.

[10] Sánchez-Borges M. Treatment of urticaria. World Allergy Organization (WAO) position paper on the diagnosis and treatment of urticaria. Journal of Allergy and Clinical Immunology: In Practice, 2021;9(5):S1-S12.

[11] Most data on treatment of urticaria involve chronic cases. Current guidelines suggest a stepwise approach to treating chronic idiopathic urticaria [9].

Chronic Inducible Urticaria (CIndU) Differential Diagnosis

Chronic inducible urticaria, also known as physical urticaria, is a group of disorders in which urticaria (hives or wheals) are triggered by various physical stimuli. The differential diagnosis for CIndU includes:

• Acute Spontaneous Urticaria: A condition characterized by sudden onset of urticaria without any identifiable trigger.
• Chronic Spontaneous Urticaria: A condition where urticaria persists for more than 6 weeks, with no apparent cause or trigger.
• Angioedema: A condition that involves swelling of the skin and mucous membranes, often accompanied by urticaria.
• Drug Eruptions: Adverse reactions to medications that can manifest as urticaria.

Other Conditions to Consider

In addition to these conditions, other differentials for CIndU include:

• Allergic Contact Dermatitis: A type of skin reaction caused by exposure to allergens such as latex or certain metals.
• Bedbug Bites: A condition characterized by itchy, red bumps on the skin caused by bedbug bites.
• Bullous Pemphigoid: An autoimmune disease that causes blistering of the skin.

Key Points

• CIndU is a group of disorders triggered by physical stimuli.
• Differential diagnosis includes various conditions such as acute spontaneous urticaria, chronic spontaneous urticaria, angioedema, and drug eruptions.
• Other conditions to consider include allergic contact dermatitis, bedbug bites, and bullous pemphigoid.

References:

[5] Chronic inducible urticaria (CIndU), also called physical urticaria, is a group of disorders in which urticaria (ie, hives or wheals) are ... [6] Differentials. Common. Acute spontaneous urticaria; Chronic spontaneous urticaria; Chronic inducible (physical) urticaria; Drug eruptions ... [8] Urticaria can be acute or chronic, spontaneous or inducible. ... What is the differential diagnosis of urticaria? ... Chronic inducible urticaria · Angioedema ... [9] Apr 25, 2024 — Chronic inducible urticaria (CIndU), also called physical urticaria, is a group of disorders in which urticaria (ie, hives or wheals) are ...