Are Asthma and Eczema Related?

Introduction

What is Asthma?

Asthma is a disease that affects the respiratory system by causing chronic inflammation of a person’s airways. ¹ This inflammation is linked to people’s airways being overly responsive to certain environmental triggers like physical activity and allergens. ¹  Atopic asthma is triggered by allergens and is the most common type of asthma. ^2,3

What is eczema?

Eczema, or atopic dermatitis, is a disease that causes dry and itchy skin on account of a flawed inflammatory immune response.⁴  Eczema tends to lead to dry skin as a result of patients consistently rubbing or itching the infected areas.⁴ Atopic dermatitis is the most commonly- seen inflammatory disorder.³

“Atopic march” is the term that is used to describe the conversion from one atopic disease to another.³ When the skin barrier is damaged, this leads to foreign substances being able to enter the skin and cause sensitivity, which is why eczema is usually the first step in the atopic march and results in further conditions such as asthma and hay fever.^3,5 As previously mentioned, this sensitivity is what causes atopic asthma, which is when a person is sensitized toward allergens within the environment.³ 

The link between asthma and eczema

Both atopic conditions are linked with chronic inflammation.³ It has been established that people with a familial history of atopic dermatitis and who currently have the disease, are more likely to develop asthma.³ “Comorbidities” is the term for multiple diseases that are seen at the same time in a patient. Alongside genetic factors and environmental triggers, a localized immune response and an irregular microbiome are also responsible for the comorbidities of eczema and asthma.^3,16 Food allergies are also likely to occur before both eczema and asthma.³ 

Causes and risk factors for asthma and eczema

Risk factors for asthma consist of a range of environmental, host and genetic factors.⁶ While it is usual for patients with asthma to have a family history of the disease, this factor is not enough, on its own, for a person to develop asthma.⁶  However, if a person inherits several genes that carry a sizable risk, then genetics can play a role in the development of asthma.⁶ Risk factors for childhood asthma include having parents with a decreased socioeconomic status, as these children have been found to have to suffer from asthma to a greater extent.⁶ Even if an asthma diagnosis is not given, children with a lower socioeconomic background have proved to experience a higher level of obstruction in the airways.⁶ Exposure to tobacco smoke from the environment can additionally lead to severe asthma.⁶ Asthma may develop in adults with or without allergen sensitization, and causes include those linked to their job (such as cleaning or painting) and in response to specific drug therapies.⁶

With eczema, childhood risk factors match those for asthma, including familial history of the disease, the child having siblings and lower socioeconomic status.^6,7 Other causes of atopic dermatitis involve exposure to allergens and tobacco smoke.⁷ 

The protein filaggrin (FLG) is responsible for the formation of the skin barrier.⁷  If the FLG protein is mutated, then people may have defects in the skin barrier, thus playing a role in triggering eczema (a chronic disease).⁷ Having low vitamin D levels has also proved to be a cause of atopic dermatitis, and research is beginning on how there may be a link between obesity and the severity of eczema.⁷

Symptoms of asthma and eczema

The most common symptoms of asthma include tightness in the chest, coughing, shortness of breath and wheezing.⁸ A study reported that the most severe symptoms in young adults involve coughing, chest tightness and fatigue.⁸ Other symptoms can include lightheadedness, the throat closing up and allergy.⁸ Markers to display the severity of asthma can be seen through sleep disruption and hindrance to physical activity during school for adolescents or general daily activities for adults.⁸ Asthma symptoms that require urgent care involve a change in colour of the lips and tongue, or around the eyes, difficulty with talking or walking because of shortness of breath, and the stomach moving in and out quickly and deeply.⁹

Eczema symptoms include a patient’s skin beginning to thicken due to the consistent rubbing and itching.⁴ Rashes that develop on the body will vary in their distribution according to a person’s age.⁴  Little children will likely have large dry and scaly patches in areas including their face and cheeks.⁴  As children grow, the rashes will be more concentrated in one area, more similar to adult eczema, becoming more abundant in areas such as the elbows, ankles, wrists and knees.⁴ Allergic rhinitis is an allergy where a person’s nose becomes irritated by an allergen, such as pollen or dust, causing sneezing alongside other symptoms.¹⁰  Patients who have eczema and allergic rhinitis may also develop a crease across their nose from continually rubbing it in an upwards motion. ⁴ People with eczema can also form wrinkles that look creased beneath the lower eyelid and a greater depth and amount of skin lines.⁴

Triggers of asthma and eczema

Asthma triggers include substances that people come into contact every day with, such as perfume, air pollution, pollen and dust mites.¹¹ Exercise, stress and negative emotions are also perceived to be triggers of asthma symptoms.¹¹  Since several asthma triggers are not easily visible to the human eye, like mould or pollen, the appearance of these triggers is inferred from the environment around the patient, such as moist indoor areas, diesel smells, or nature in summer.¹¹ 

The National Eczema Association informs us that eczema triggers include dry skin that makes the skin condition scaly and tight and irritants such as soap or detergent that burn the infected areas on a patient’s body.¹²  Feeling emotionally wound up and stressed can also trigger eczema.¹² Extremes of climate can additionally cause eczema on a person’s body to flare up, and patients with eczema can experience allergic reactions to insect bites, cockroaches and pet dander (skin shed from animals similar to dandruff).¹²

Similarities and differences between asthma and eczema

The prevalence of both eczema and asthma becomes higher when children grow to become adolescents.¹³ However, eczema tends to decrease and plateau when adolescents become adults, whereas asthma prevalence increases when reaching adulthood.¹³ As mentioned previously, while a putative link between obesity and eczema severity is beginning to be established, obesity is connected to patients having eczema and asthma simultaneously.^7,13 Stress and several of the same allergens are found to trigger both asthma and eczema.^11,12,13

Managing and treating inflammation 

There are many types of anti-inflammatory medications available for the treatment of asthma, and these should be administered alongside regular monitoring to assess the effectiveness of the medicine.¹⁴ Education on the proper use of an inhaler and recognizing the worsening symptoms of asthma is also important.¹⁴

With eczema, allergy testing for any food or environmental allergies may help to mitigate eczema symptoms brought on by a substance to which the patient is allergic.⁴ Topical steroids that are anti-inflammatory are the most commonly prescribed treatment for eczema and should preferably be applied in ointment form.⁴ As children tend to find eczema to be itchier during the night-time, antihistamine (oral medication) can be given for disrupted sleep.⁴ 

Lifestyle changes

Since a study deduced that over half the children with atopic dermatitis also develop a respiratory disease such as asthma, it is important to have earlier prevention strategies in place to initially reduce the prevalence of eczema.⁷  With eczema being prevented, the entire chain of atopic march can therefore be avoided.⁷

These lifestyle strategies can include ensuring that your house is free from allergens like mould and smoke and minimizing pet dander by frequently dusting and hoovering. ¹⁵  Managing stress and anxiety is also a significant way to reduce triggers, and this can be done by seeking help and spending more time with friends and family.¹⁵  It is worth looking at changing the detergents and soaps used for baths and washing clothes if you notice a pattern of these substances irritating your skin further.⁴

Summary 

Eczema and asthma both have many things in common due to being inflammatory diseases. They both negatively impact people’s quality of life and are triggered by many of the same substances and internal stimuli, such as a person’s emotional wellbeing. While the number of triggers for eczema and asthma can seem overwhelming, there are sufficient treatment and management options in place for most triggers. Being educated about general triggers is the best idea for managing these diseases if they affect you, as you will have a better idea of how to avoid the triggers and symptoms and how to respond if you come into contact with triggers.