How Do Allergies and Asthma Affect Sleep?

All allergic diseases, including allergic rhinitis, asthma, and atopic dermatitis, have become more common over the past 50 years. Allergic rhinitis affects approximately 30 percent of the population in the United States, while asthma affects approximately 8 percent.

The symptoms of allergic rhinitis and asthma often occur during the nighttime, having a detrimental effect on the quality of sleep. Sleep disorders, such as obstructive sleep apnea, are also becoming more common in both children and adults and may be related to allergic diseases.

The symptoms of allergic disease worsen during the nighttime hours for various reasons.

• First, the body’s cortisol level, which is an anti-inflammatory hormone, is at its lowest point during the night, causing a higher level of inflammation in the nose and the lungs.
• Next, allergy to dust mites and/or indoor household pets is quite common, with exposure being highest during the night, thereby increasing allergic symptoms.
• Lastly, histamine, an important chemical in allergic reactions, is involved in the regulation of sleep but may also worsen symptoms of allergic rhinitis and asthma.

All of these aspects contribute to poor sleep quality as a result of worsening symptoms of allergic disease during the night.

Asthma symptoms during the night are much more of a concern than daytime symptoms, according to the National Asthma Education Prevention Program/Expert Panel Report-3. This is at least in part because the lungs are more susceptible to bronchospasm as a result of lower cortisol levels in the body at night.

Worsening asthma during the night can have a significant impact on the quality of sleep, leading to daytime fatigue, poor work and school performance, and a decrease in the overall quality of life.

Obstructive sleep apnea, a condition that results in breathing pauses during sleep as a result of obstruction of the upper airway from excess tissue or airway collapse, can worsen the symptoms and severity of asthma.

Airflow is also decreased during sleep apnea, leading to low oxygen levels in the bloodstream and strain on the heart. Additionally, narrowing of the small airways leads to more irritation and contraction of the smooth muscle around the airways in people with asthma, worsening asthma symptoms.

Allergic rhinitis commonly affects a person’s quality of sleep. In fact, a number of studies confirm that a large percentage of people with nasal allergies feel that their symptoms interfere with sleeping.

Nasal congestion seems to be the most common symptom to interfere with the quality of sleep, although other symptoms of allergic rhinitis, such as sneezing, runny nose, and itchy nose and eyes, can also contribute to problems with sleeping.

People with allergic rhinitis, especially children, are also likely to develop enlargement of the tonsils and adenoids, which, along with nasal congestion, can lead to snoring and obstructive sleep apnea, which often has a major impact on a person’s quality of sleep.

Atopic dermatitis is associated with itching of the skin, which can be severe and may also be worse at night when a person is trying to go to sleep. Studies have shown that when a person has severe atopic dermatitis, causing itching and scratching, the quality of sleep is severely affected.

Atopic dermatitis-associated itching may be worse at night as a result of the presence of dust mites or pet allergens, increased histamine levels related to sleep regulation, or as a result of the increased perception of itching when a room is dark and quiet (a decrease in other stimulation) and a person is attempting to fall asleep.

Treatments that improve asthma symptoms, allergic rhinitis symptoms, and atopic dermatitis are also likely to improve your quality of sleep. For example:

• Asthma controllers have been shown to improve sleep quality, particularly in children.
• Treatment of nasal congestion, such as with intranasal corticosteroid nasal sprays, may reduce lymphoid hypertrophy and obstructive sleep apnea, thereby improving the quality of sleep.
• Decreasing itching associated with atopic dermatitis with the use of topical corticosteroids will also improve the quality of sleep by decreasing nighttime scratching.