The crossover between pulmonology, dermatology, and immunology had always intrigued me as I was born with eczema and was diagnosed with asthma five years later. After conducting research about the correlation between eczema and asthma, I discovered that this story was indeed not unique to me.
Eczema or dermatitis is defined as a medical condition in which irritants cause patches of skin to become itchy, rough, inflamed, blistery, and in extreme cases it may even cause them to bleed (2). Whereas asthma is defined as a medical condition in which the air passageways of the lungs become narrow due to swelling and excessive mucus production which hinder breathing leading to severe lung discomfort in the form of shortness of breath, coughing, and wheezing (3).
The study I conducted evaluated the effect of having the pre-existing condition of eczema on the incidence of developing asthma in children aged 13-14 years in North America (Barbados, Hamilton, Saskatoon, and Seattle). Using confided health records from the International Study of Asthma and Allergies in Childhood’s database, I compared the number of asthmatics in two groups of 200 randomly-picked 13-14 year old patients (one whose patients had pre-existing eczema and the other whose patients did not).
Figure 1. The error bars for the experimental group represents ± 11.4 standard deviations and ± 14.7 standard deviations for the control group.
There are many likely reasons behind why asthma ‘preys’ upon patients with eczema. Both eczema and asthma are affiliated with allergies. Patients with allergies are sensitive to their surroundings, especially when it is glutted with pollen, dust, pet dander, etc. For example, pollen can collect in the ventilation tract and make breathing difficult while also contacting with the skin causing irritation, frequent itching, and rashes. Another possible explanation is that the skin may be acting as a sensory organ as well as a signaling organ, thereby releasing antigens into the bloodstream, triggering allergic reactions like inflammation in the respiratory tract. The immune systems of patients who have both eczema and asthma are hypersensitive. Common allergens like pollen and dust which do not evoke a reaction in most individuals can produce allergic manifestations in patients who have a general predisposed sensitivity to allergens. In other words, sensitivity to certain substance(s) often correlates to sensitivity to other substances.
The phenomenon where children diagnosed with eczema eventually develop asthma months or years later is becoming so universal that medical professionals are labelling the progressions of diseases like eczema to asthma as, “the atopic march.” A group of medical researchers discovered that a promising 75 percent of asthmatics have the medical condition of eczema in common. Similarly, an Australian study yielded results that showed that pediatric patients with pre-existing eczema were up to 50 percent more susceptible to becoming asthmatic later on than those who did not have eczema. Other studies proposed the percent likelihoods to be as high as 63 percent. Medical experts believe that aggressively diagnosing and treating eczema can prevent the condition from worsening, and thus decrease its likelihood to trigger the development of asthma (Bottrell).
This is not to say that only patients with eczema are susceptible to develop asthma. In fact, the study I conducted showed that about 60 percent of patients developed asthma without having to develop eczema first. Thus, eczema is not a necessary prerequisite for the development of asthma. Moreover, about 22 percent of patients who had eczema did not develop asthma. Therefore, not every patient who develops eczema will develop asthma. For all of these patients, either their lungs or their skin had more antibodies present to fight off the foreign substances making it less hypersensitive than the other.
With all this talk about allergies serving as the link between eczema and asthma, could having allergies also work as a predisposition to eczema and eventually asthma? Something to think about, especially considering that spring is right around the corner.
Written by: Melissa-Maria Kulaprathazhe
- Bottrell, John. “The Link Between Eczema and Asthma.” Health Central. 7 February 2011.
- Mayo Clinic Staff. “Dermatitis (eczema).” Mayo Clinic Health Letter. Mayo Clinic, 26 July 2014. Web. 1 Mar. 2017.
- Mayo Clinic Staff. “Diseases and Conditions: Asthma.” Mayo Clinic Health Letter. Mayo Clinic, 30 August 2016. Web. 1 Mar. 2017.