Links To And Excerpts From Dust Mite Allergy From StatPearls-Part 2

In this post, Links To And Excerpts From Dust Mite Allergy From StatPearls-Part 2, I review the treatment of dust mite allergy from Dust Mite Allergy from Treasure Island (FL)  StatPearls Publishing; Last Update: August 16, 2020.

For the evaluation of dust mite allergy, please see my post, Links To And Excerpts From Dust Mite Allergy From StatPearls-Part 1.

Here are excerpts from Dust Mite Allergy:

Treatment / Management

The most effective intervention for dust mite allergy is primary prevention, that is allergen avoidance. This can be achieved by reducing the levels of mite allergens.

Measures for allergen avoidance in the bedroom

  • Covering of mattresses and pillows with fine woven fabric or plastic. These prevent the penetration of the house dust mites.
  • Hot washing of bedding, at least once a week in hot water (130 – 140°F), bedding can also be frozen overnight to kill dust mites.
  • Removal of carpets and drapes
  • Room air cleaner with a high-efficiency particulate air (HEPA) filter. These filters can remove up to  99.7% of particles as small as 0.1 microns.

Measures for allergen avoidance in the whole house

  • Humidity control to 45 percent humidity or less
  • Vacuum cleaning. They reduce dust disturbances. Dust disturbances include moving furniture, throw pillows, drapes, or bedding that can make mite allergens airborne, thus increasing exposure.
  • Cross ventilation
  • Use of acaricides, which is a chemical to kill the house dust mites in the house. The disadvantages include short-lived effects and safety concerns for use at home.

Over the counter medications. These provide symptomatic relief to the allergic manifestations.

  • Antihistamines
  • Nasal corticosteroids
  • Leukotriene receptor antagonists
  • Cromolyn sodium (mast cell stabilizers)
  • Decongestants

Nonpharmacological measures. These are safe, effective, and convenient modalities to help manage symptoms of dust mite allergy. Their use as an adjunctive helps to reduce the use of pharmacological drugs.

  • Saline nasal irrigation
  • Saline nasal sprays

HDM allergen immunotherapy (AIT). This is also known as desensitization. AIT has been in use for achieving clinical tolerance to allergens through the administration of allergen extracts to the sensitized individual. It is effective in the treatment of Type I allergic diseases induced by IgE in terms of alleviating the clinical manifestations of allergic rhinitis and asthma, reducing the use of symptom-relieving medication, and improving the quality of life. It provides an effective improvement in clinical symptoms, reduces the need for rescue medications, improves lung function, and brings about intrinsic disease-modifying effects such that the allergic inception of asthma and new sensitizations can be completely or partially abrogated. The effects persist for years after therapy discontinuation. The following forms of immunotherapy are available:

  • Subcutaneous immunotherapy (SCIT). The house dust mite allergenic extracts are injected in an incrementally increasing dose into the affected individual. The therapeutic dose range of SCIT is between 500 and 2000 AU (activity units) for a targeted maintenance dose of 7 micrograms of Der p 1 and 10 micrograms of Der f 1. The build-up or the induction phase is about 8 – 24 weeks, followed by 3 to 5 years of a monthly maintenance phase. SCIT induces “allergenic tolerance.” The mechanism involves the induction of FOXP3+ CD25+ regulatory T cells (Tregs) specific to such allergens, induction of blocking antibodies such as IgG4 and IgA2, as well as induction of regulatory cytokines such TGF-beta and IL-10  that skew the response from a TH2 to a Treg or TH1 pattern. It provides an effective improvement in clinical symptoms, reduces the need for rescue medications, and improves lung function.
  • Sublingual immunotherapy (SLIT). It is an effective alternative to SCIT. The immune responses include the induction of circulating, allergen-specific Th1, and regulatory CD4+ T cells that lead to clinical tolerance. It can be used for treating extrinsic mild to moderate atopic dermatitis in children who are sensitized to house dust mites.
  • Alternative routes include oral, nasal, epicutaneous, bronchial, and intra-lymphatic. Many of these routes have been tried and attempted but abandoned due to increased adverse effects or difficult administration.
  • Allergy specific immunotherapy (AIT). This therapy is based on recombinant allergens, rather than on allergen extracts. Modified dust-mite allergens that are hypoallergenic derivatives of group 1 and group 2 have been developed. This is promising towards better efficacy, lesser adverse effects, and better administration, as compared with immunotherapy using allergic extracts. Using a combination of hypoallergenic groups 1 and 2, efforts are being made to develop vaccines.

Treatment of asthma. It depends on the severity of asthma. Short-term relief is provided through short-acting beta-agonists (SABA). The long term relief is provided by anticholinergics, long-acting beta-agonists (LABA), and low dose inhaled corticosteroids. Oral corticosteroids are used in acute exacerbations of asthma. Leukotriene antagonists and mast cell stabilizers may be useful.

Differential Diagnosis

Other than dust mites, house dust allergy can be caused by the following allergen sources:

  • Mold. The fungus grows in a humid environment like house basements, kitchens, gardens, and bathrooms. The spores of the mold become airborne, which on inhalation leads to allergic rhinitis.
  • Cockroaches. These are found in a variety of environments. The saliva, fecal matter, and shed off parts of cockroaches serve as potential allergens for triggering allergies. Around 68 percent of households in the USA are known to have cockroach allergens. The percentage increases further in urban areas.
  • Pollen. Flowers, grass, weeds, and trees are sources of pollens that constitute an essential component of household dust. These are a common cause for triggering allergic reactions.
  • Pets. Fur, feathers, animal hair, dander, saliva, and fecal matter all serve as allergens.

Dust mite allergy can be confused with non-allergic forms of rhinitis. These include the following:

  • Vasomotor rhinitis. It leads to chronic sneezing and can be triggered by weather change, certain foods or medications, emotions, underlying chronic health problems, or certain odors.
  • Rhinitis medicamentosa. It occurs due to the overuse of nasal decongestants and cocaine users.
  • Atrophic or senile rhinitis. It occurs due to the hardening and thinning of the nasal turbinates with age or multiple nasal surgeries, making it more susceptible to damage and infection.
  • Non-allergic rhinitis with eosinophilia syndrome (NARES)
  • Infectious rhinitis. It can be bacterial or viral.
  • Chemical rhinitis
  • Hormonally induced rhinitis

Prognosis

Minimizing or avoiding the dust mite allergens leads to fewer allergic reactions. However, house dust mite allergy leads to a decreased quality of life in the long run. This can be explained by the following:

  • Increased school and work absenteeism
  • Decreased concentration leading to poor work performance
  • Driving performance, as well as cognitive functions of individuals with a long duration of work, is markedly impaired
  • Treatment of allergic symptoms in asthmatics is a substantial economic burden on families
  • Disturbed personal relationships
  • Decreased daily productivity
  • Inability to participate in recreational activities and sports

The cost-benefit analysis demonstrates that immunotherapy is more cost-effective in the long term as compared with symptomatic treatment.

Complications

Start here

 

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