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FACT SHEET: Asthma (also known as “reactive airway disease” and “bronchial asthma”)

Date of Publication: May 19, 2015

Is the initiation of non-invasive dental hygiene procedures* contra-indicated?

  • No.

Is medical consult advised?  

  • No, assuming asthma is well controlled and there are no potential acute triggers.

Is the initiation of invasive dental hygiene procedures contra-indicated?**

  • No.

Is medical consult advised? 

  • See above.

Is medical clearance required? 

  • No, not typically. However, if asthma is suspected to be severe and unstable, medical clearance should be obtained. Similarly, prolonged use and/or high doses of systemic (oral) corticosteroids may predispose to infection, and medical clearance should be sought in these circumstances. Furthermore, if prednisone or other systemic steroid is being taken on an ongoing basis for chronic asthma, the patient/client’s physician may wish to increase the regular dose to prevent an adrenal crisis during a particularly stressful appointment.

Is antibiotic prophylaxis required?  

  • No, not typically. However, antibiotic prophylaxis should be considered for patients/clients at risk of immunosuppression (e.g., prolonged use and/or high doses of systemic corticosteroids, or use of biologics1 in severe asthma). 

Is postponing treatment advised?

  • No, if asthma is well controlled (green zone).2 Yes, if asthma is severe and unstable (yellow through red zones3, as evidenced by wheezing, coughing, shortness of breath, etc.); routine dental hygiene treatment should be postponed until better control is achieved. An acute asthma attack requires immediate management. If status asthmaticus is suspected, emergency protocol should be initiated and prompt transfer to an emergency department is indicated. 

Oral management implications

  • In order to avoid an acute asthma attack in the office setting, the dental hygienist should determine the severity and stability of the patient/client’s asthma via good history-taking. Questions should be asked regarding precipitating factors, frequency and severity of attacks, the times of day when attacks usually occur, whether this is a current or past problem, and whether the patient/client has ever received emergency treatment for an attack. 
  • Seasonality is characteristic of patients/clients’ asthma when signs/symptoms are triggered by plan allergens (e.g., in spring, summer, or fall) or cold (in winter). Elective dental/dental hygiene procedures may need to be scheduled around high-risk months.
  • Patients/clients should be asked to bring their inhalers (particularly reliever [“rescue”] inhalers) to their oral healthcare appointment so these are available if required.
  • Use of air polishers, power-driven polishers, and ultrasonic scalers should be avoided or minimized, because their use may precipitate or worsen breathing problems, or result in pathogen aspiration into the lungs. Tooth enamel dust and aerosol creation should be minimized. Prolonged supine positioning should be avoided.
  • Because stress is a precipitating factor in some asthma attacks, the dental hygienist and other staff members should endeavour to provide a stress-free environment.
  • Status asthmaticus (also known as severe acute asthma) is the most serious manifestation of asthma. Signs of this severe and prolonged attack of asthma (one refractory to usual therapy4) include progressive dyspnea, jugular venous pulsation, cyanosis, and pulsus paradoxus (a fall in systolic pressure with inspiration). Status asthmaticus, which is often triggered by a respiratory infection, can lead to exhaustion, severe dehydration, peripheral vascular collapse, and death.
  • Dental hygienists should recognize the signs and symptoms of a severe/worsening attack: inability to finish sentences with one breath; tachypnea with respiratory rate of 25 breaths/minute or more; tachycardia with heart rate of 110 beats/minute or more; diaphoresis (sweating); accessory muscle usage (e.g., sternocleidomastoid and scalene neck muscle assistance with breathing); pulsus paradoxus (which entails large decrease in systolic blood pressure during inspiration); ineffectiveness of bronchodilators to relieve dyspnea; and recent drop in forced expiratory volume in one second (FEV1) by spirometry.  
  • For an acute asthma attack in the oral healthcare setting:
    • position the patient/client for maximum comfort (usually upright in the chair)
    • administer oxygen
    • encourage the patient/client to take 2 puffs, repeated as necessary, of his/her own reliever/rescue inhaler (i.e., aerosolized short-acting bronchodilator, such as salbutamol5) or, if available, clinic’s reliever/rescue inhaler
    • if signs/symptoms fail to improve or worsen (e.g., when 3 doses of aerosolized bronchodilator fail to resolve acute episode):
      • activate emergency response (911) for medical attention
      • administer epinephrine 1:1000 dilution, 0.3 mL (0.3 mg) to 0.5 mL (0.5 mg) IM6 or SC7 (adult patient) and repeat every 10 minutes as required 
  • Nitrous oxide is contraindicated for patients/clients with severe asthma.  
  • The analgesic of choice for asthmatic patients/clients post-treatment is acetaminophen (and not ASA or nonsteroidal anti-inflammatory drugs [NSAIDS]; see below).
  • Patients/clients using asthma medications should receive education on prophylaxis. This includes instruction on rinsing their mouth with water after using a steroid inhaler to reduce the incidence of oral candidiasis. Occurrence of oral thrush can also be reduced if a spacer (aerosol-holding chamber) is attached to a steroid metered-dose inhaler (MDI).8
  • Dental erosion can be reduced by rinsing the mouth with sodium bicarbonate solution or using neutral sodium fluoride rinses after using β2 (beta2) agonist inhalers. An MDI spacer will reduce medication scatter to the mouth and throat and increase delivery to the targeted lungs.9
  • Immediate brushing of the teeth after using an inhaler should be avoided, because it may damage enamel already weakened due to acidic pH.
  • Comorbid gastroesophageal reflux (GERD) should be treated to reduce risk of dental erosion.
  • Fluoridated or antimicrobial (e.g., chlorhexidine) mouth rinses should be considered for daily use by patients/clients on inhalation therapy.
  • Sugary medications should be avoided when appropriate. Many inhaled asthma drugs contain sweeteners (e.g., lactose), which increase cariogenic potential.
  • Sulfite preservatives (found in local anaesthetic solutions that contain epinephrine or levonordefrin) can cause allergic-type reactions in susceptible persons. Although rare, acute asthma attacks can be triggered. Therefore, local anaesthetics without vasoconstrictor should be considered in at-risk patients/clients.
  • In patients/clients taking theophylline10 for asthma management, certain antibiotics should be avoided in order to prevent drug interactions. These include ciprofloxacin and some macrolide antibiotics (e.g., erythromycin and clarithromycin).

Oral manifestations

  • Mouth breathing, nasal symptoms, and allergic rhinitis11 are common in environmental allergy-induced asthma.
  • Patients/clients who are mouth breathers may have higher palatal vault, greater overjet, and an increased prevalence of posterior crossbite. Malocclusion is common in mouth breathing asthmatic children.
  • Calculus susceptibility is elevated.
  • Gastroesophageal reflux, which may be exacerbated by the use of β2-agonists and theophylline, is a common comorbidity. This reflux can lead to erosion of enamel.
  • Medications used to manage asthma — principally bronchodilators, corticosteroids, and anticholinergics — can contribute to oral disease.12 β2 agonist inhalers (bronchodilators) and anticholinergics reduce salivary flow, resulting in xerostomia. In addition, β2 agonist inhalers also lower plaque pH (possibly contributing to dental erosion), cause unpleasant taste sensation, and are associated with increased prevalence of dental caries and gingivitis in patients/clients with moderate to severe asthma. Oral candidiasis, gingivitis, and/or periodontitis occur in some patients/clients who use inhaled corticosteroids for long periods of time or at high dose. The use of steroid inhalers can also result in throat irritation, voice impairment, cough, dry mouth, and, rarely, tongue enlargement. Patients/clients using inhaled asthma medications are also at increased risk of dental erosion and periodontal disease.
  • Sore throat is a side effect of several of the biologics used to treat severe asthma (including reslizumab, benralizumab, dupilumab, and tezepelumab).
  • Bone mineral density, including that of the mandible, may be reduced by long-term use of inhaled corticosteroids (ICS).

Related signs and symptoms

  • Asthma is a chronic inflammatory respiratory disease characterized by reversible episodes of airway reactivity manifesting as bronchial smooth muscle spasm, inflammation of bronchial mucosa, mucus hypersecretion, and sputum plugging. This results in recurrent episodes of wheezing, coughing, and dyspnea (shortness of breath). There are three types of asthma: allergic (extrinsic), non-allergic (intrinsic), and mixed (combination of extrinsic and intrinsic).13 Attacks may be provoked by environmental allergens (e.g., pollen, ragweed, molds, foods, cockroaches, and dust mites), environmental pollutants and irritants (e.g., smoke and chemicals such as scent and house sprays), respiratory tract infections, cold air, exercise, certain medications (ASA14, nonsteroidal anti-inflammatory drugs, cholinergic drugs, and β-adrenergic blocking drugs), and highly emotional states (i.e., anxiety, stress, and excitement).
  • Asthma affects more than 3.8 million people in Canada, with 850,000 of those being children under the age of 14 years. Onset may occur in childhood or in adulthood, with 2/3 of all cases being diagnosed before age 18 years. Prevalence has greatly increased worldwide since the 1960s. Symptoms and signs tend to improve in adulthood, and in some children  (particularly boys), asthma resolves spontaneously after puberty. Asthma occurs predominately in boys until puberty (2:1 male-to-female ratio), whereas the majority of adult-onset cases diagnosed after age 40 years occur in females. 
  • Typical signs and symptoms of asthma include cough that is worse at night and chest tightness. Onset is usually sudden, with peak signs/symptoms occurring within 10 to 15 minutes. Respirations become difficult and are accompanied by expiratory wheezing. Tachypnea (fast breathing) and prolonged expiration (due to narrowing of airways) are characteristic. Episodes are usually self-limiting, but severe attacks necessitate medical assistance.
  • Rhinosinusitis and obesity are common comorbid conditions.
  • Asthma deaths occur most often in persons aged more than 45 years of age and largely preventable, often being associated with delays in delivery of appropriate medical care.
  • Exposure by oral healthcare personnel to methacrylates found in dental restorative and sealant materials has been linked to occupational asthma.

References and sources of more detailed information

Date: November 11, 2014
Revised: October 2, 2019; July 17, 2023


1 Injectable biologics used to treat asthma include omalizumab, mepolizumab, reslizumab, benralizumab, dupilumab, and tezepelumab.
2 The three asthma control zones are: green (state of total control of asthma) — symptom-free, able to participate in normal activities, attending work or school sleeping through the night without asthma symptoms, using reliever medication no more than twice per week for asthma symptoms [with exception of one dose before exercise]; yellow (state of warning of loss of control) — difficulty with asthma symptoms during regular activities or exercise, or asthma symptoms that begin to disturb sleep, or cold or chest infection, or reliever medication required three or more times per week, or missing school or work for asthma; and red (state of emergency that requires immediate medical attention) – excessive coughing or wheezing or chest tightness, extremely labored breathing, sweating, gasping voice, pale or blue lips or fingernails, anxiety or fear, decreased activity level, reliever medication apparently ineffective in relieving symptoms).
3 See footnote 2 above.
4 in particular, short-acting beta-agonist agents (“rescue medications”)
5 Salbutamol is also referred to as “albuterol”, particularly in the United States.
6 IM = intramuscular
7 SC = subcutaneous
8 MDIs are also known as hydrofluoroalkane (HFA) inhalers.
9 Spacer chambers are not typically used with dry powder inhalers (DPIs).
10 Theophylline is an older asthma drug, which has been supplanted by other, more effective medications for first-line management of asthma.
11 Allergic rhinitis (present in nearly 80% of persons with asthma) could be a confounding factor in the pathogenesis of oral disease. Further research is required.
12 Dry powder formulations of inhalable asthma drugs (i.e., dry powder inhalers, or DPIs) are particularly prone to creating an acidic oral environment. Hydroxyapatite dissolution occurs below a pH of 5.5.
13 While laboratory assessments and studies are not routinely indicated for the diagnosis of asthma, they may be used to exclude other diagnoses. Pulmonary function tests include spirometry (“blow test”) before and after administration of a short-acting beta agonist (SABA, a bronchodilator). Reversibility is demonstrated by an increase in pulmonary function after inhalation of the SABA.
14 Asthmatic persons with nasal polyps are at particularly increased risk for allergy to ASA (and NSAIDs).

* Includes oral hygiene instruction, fitting a mouth guard, taking an impression, etc.
** Ontario Regulation 501/07 made under the Dental Hygiene Act, 1991. Invasive dental hygiene procedures are scaling teeth and root planing, including curetting surrounding tissue.