hexamethylene diisocyanate allergic asthma

Hexamethylene diisocyanate (HDI) exposure can cause an allergic, asthma-like syndrome in individuals who are exposed to it for a prolonged period. The symptoms of this condition include:

• Shortness of breath [1]
• Wheezing [2]
• Bronchitis [3]
• Coughing [4]

In some cases, even low levels of future exposure can trigger these symptoms once an allergy has developed [5]. This condition is characterized by a local irritation to the nasal and respiratory tract, as well as an asthma-like condition in sensitized individuals at air vapor concentrations ranging from approximately 0.0002 to 0.02 ppm [14].

It's worth noting that preventing asthma and death from diisocyanate exposure is crucial, and there are resources available for this purpose [15]. The accurate diagnosis of diisocyanate asthma requires a systematic approach that combines information obtained from the occupational history, immunologic tests, and physiologic studies [10].

Symptoms usually develop very slowly over a long time (months or years), but they can also develop within a couple of weeks after first breathing in HDI [11][12]. This condition is one of the leading causes of occupational-induced asthma bronchial worldwide [13].

Hexamethylene diisocyanate (HDI) allergic asthma can manifest in various ways, depending on the individual's sensitivity and exposure levels. Here are some common signs and symptoms associated with HDI-induced asthma:

• Respiratory issues: Burning and irritation of the nose, throat, and mucous membranes of the lungs; cough; laryngitis; bronchitis [6][6]
• Asthma-like condition: Sensitized individuals may experience an asthma-like condition upon repeated exposure to HDI, characterized by wheezing, breath shortness, cough, and chest tightness [10]
• Skin allergy: HDI can cause a skin allergy, leading to symptoms such as redness, itching, and rashes
• Headache, dizziness, nausea, and vomiting: These effects may occur due to exposure to high concentrations of HDI [8]

It's essential to note that not everyone exposed to HDI will develop allergic asthma or experience these symptoms. However, if you suspect you have been exposed to HDI and are experiencing any of these symptoms, it is crucial to seek medical attention.

References:

[6] At concentrations greater than 0.0006 ppm, burning and irritation of the nose, throat and mucous membranes of the lungs; cough; laryngitis; bronchitis; [8] headache, dizziness, nausea and vomiting. [10] Details of asthma symptoms including the frequency of wheezing, breath shortness,

Diagnosing Hexamethylene Diisocyanate (HDI) Allergic Asthma

Hexamethylene diisocyanate (HDI) is a chemical used in various industrial processes, and exposure to it can cause allergic asthma. Diagnosing HDI-induced asthma requires specific tests that measure the body's immune response to this chemical.

Blood Tests for IgE Antibodies

One of the diagnostic tests for HDI-induced asthma is a blood test that measures the presence of IgE antibodies specific to HDI (Hexamethylene diisocyanate). This test, also known as an allergy test, can help determine if you are allergic to HDI. [2]

ImmunoCAP FEIA Method

Another diagnostic method used for detecting allergen-specific IgE is the ImmunoCAP FEIA assay. This in vitro testing mode is primarily used for allergy diagnosis and can help identify individuals with HDI-induced asthma. [4]

Measuring Antibodies in Blood

Tests are available that measure the antibodies produced by the body after exposure to hexamethylene diisocyanate. These tests can help diagnose HDI-induced asthma, but their sensitivity may vary. [5]

Diagnostic Criteria for Isocyanate-Induced Asthma

A RAST score of 3 or greater is considered diagnostic of isocyanate-induced asthma, including HDI-induced asthma. This criterion helps healthcare professionals confirm the diagnosis with a high degree of specificity. [6]

Challenges in Diagnosing Occupational Asthma

Diagnosing occupational asthma caused by diisocyanates like HDI can be challenging due to difficulties in quantifying and controlling workplace exposures. There is no simple diagnostic test for this disease, making it essential to consider recent concepts in diagnosis and documentation. [8]

Inhalation Tests for Diisocyanate-Induced Asthma

Single-blind inhalation tests have been conducted with diisocyanates, including HDI, to assess their potential to cause asthma. These tests can provide valuable information on the diagnostic criteria for isocyanate-induced asthma. [9]

Accurate Diagnosis and Documentation

A guide is available that assists in accurately diagnosing occupational asthma related to diisocyanates and documenting actual cases. This resource provides essential information for healthcare professionals working with patients exposed to HDI. [7]

Treatment Options for Hexamethylene Diisocyanate Allergic Asthma

Hexamethylene diisocyanate (HDI) allergic asthma is a severe and potentially life-threatening condition that requires prompt medical attention. While there is no specific treatment to cure HDI-induced asthma, various medications can help manage symptoms and prevent exacerbations.

Corticosteroids

• Corticosteroids are the primary treatment for HDI-induced asthma ([1], [7]). They work by reducing inflammation in the airways and suppressing the immune system's response.
• Inhaled corticosteroids (ICS) are often prescribed as a first-line treatment, with options including fluticasone, budesonide, or ciclesonide ([4], [9]).
• Oral corticosteroids may be used for more severe cases or during acute exacerbations ([1], [7]).

Bronchodilators

• Bronchodilators are medications that help relax the airway muscles and improve breathing. They can be used in combination with corticosteroids to manage symptoms.
• Short-acting beta-agonists (SABAs) like albuterol or levalbuterol may be prescribed for acute asthma attacks ([1], [7]).
• Long-acting beta-agonists (LABAs) like salmeterol or formoterol can be used as add-on therapy to ICS in patients with persistent symptoms ([4], [9]).

Immunomodulators

• Immunomodulators are medications that modify the immune system's response. They may be considered for patients who do not respond adequately to corticosteroids and bronchodilators.
• Omalizumab, a monoclonal antibody, has been studied in patients with HDI-induced asthma ([5], [11]).

Other Treatments

• Antihistamines or leukotriene modifiers may be prescribed for mild symptoms or as add-on therapy to corticosteroids and bronchodilators ([1], [7]).
• In severe cases, hospitalization and oxygen therapy may be necessary to manage acute exacerbations ([1

Differential Diagnosis of Hexamethylene Diisocyanate Allergic Asthma

Hexamethylene diisocyanate (HDI) is a chemical used in the production of polyurethane foams, coatings, and adhesives. Exposure to HDI can cause an allergic asthma-like syndrome, which requires prompt diagnosis and treatment to prevent chronic morbidity.

Key Points for Differential Diagnosis:

• Occupational History: A thorough occupational history is essential to identify exposure to HDI or other diisocyanates.
• Symptoms: Symptoms of HDI-induced asthma include shortness of breath, wheezing, bronchitis, and coughing. These symptoms can be similar to those caused by other respiratory conditions.
• Immunologic Tests: Immunologic tests such as specific IgE and IgG measurements can help diagnose HDI-induced asthma.
• Physiologic Studies: Physiologic studies like spirometry and peak flow measurements can also aid in diagnosis.

Differential Diagnosis Considerations:

• True Occupational Asthma: True occupational asthma is caused by high-level irritant exposure at work or sensitization to diisocyanates. A clear diagnosis usually requires a combination of investigations.
• Coincidental Asthma: Asthma may be coincidental to or aggravated by work exposures, but not directly related to HDI exposure.
• Other Respiratory Conditions: Other respiratory conditions such as chronic obstructive pulmonary disease (COPD), pneumonia, and bronchitis can present with similar symptoms.

References:

• [3] Hexamethylene diisocyanate asthma is associated with genetic polymorphisms of CD14, IL-13, and IL-4 receptor α. J Allergy Clin Immunol. 2011;128:418–420.
• [10] Diisocyanates are currently the most frequently reported cause of chemically induced occupational asthma and their use continues to rise.
• [12] Three diisocyanates cause occupational asthma (OA): toluene diisocyanate (TDI), 4,4-diphenylmethane diisocyanate (MDI), and 1,6-hexamethylene diisocyanate (HDI).
• [14] Diisocyanates, toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and hexamethylene diisocyanate (HDI) are the most common chemicals that cause asthma.