Childhood Asthma Linked to Increased Migraine Risk

Pauline Anderson

February 23, 2017

Children with persistent asthma have an increased risk for migraine, a new study suggests.

The research also shows that children treated long term with nasal or inhaled corticosteroids, or antihistamine therapies, have a decreased risk for migraine.

The results highlight the importance of screening for asthma and allergic symptoms in children with migraine, said study authors, led by Camille Aupiais, MD, Unit of Clinical Epidemiology, Assistance Publique-Hôpitaux de Paris, CHU Robert Debré, Paris, France.

The study was published online February 4 in Headache.

Migraine is common in children, with prevalence rates ranging from 3.3% to 21.4%. Several studies have reported associations between migraine and atopic diseases, such as food allergy, asthma, and allergic rhinitis.

Researchers performed a case-control study of 229 children diagnosed with migraine (147 without aura and 82 with aura) at three European tertiary care hospitals (Robert Debré in Paris, France; Sacco in Milan, Italy; and Santa Maria della Misericordia in Udine, Italy) between June and August 2014.

The study also included 406 control children seen in the emergency department for a minor injury to an upper or lower extremity.

Detailed Data

Investigators collected detailed demographic and medical data through parent interviews and from medical records. The information included history of allergy and atopic diseases (asthma, allergic rhinitis, allergic conjunctivitis, IgE-mediated food allergy, atopic dermatitis) and use of antiallergic therapies.

In the migraine group, 28.4% had a history of asthma compared with 31.1% in the control group.

Compared with the absence of asthma, persistent asthma was associated with increased risk for migraine (odds ratio [OR] 4.57; 95% confidence interval [CI], 2.04 - 10.24). This was the case for both migraine with aura and migraine without aura.

Children with migraine were less likely to have been treated with inhaled or nasal corticosteroid (OR, 0.34; 95% CI, 0.15 - 0.76) or antihistamine therapy (OR, 0.33; 95% CI, 0.18 - 0.60). Again, subgroup analysis for migraine groups confirmed the negative association.

The median number of monthly migraine episodes was higher in children with persistent asthma than in children with intermittent asthma or nonasthmatic children.

The researchers found a negative association between allergic rhinitis or conjunctivitis and migraine.

To investigate the large variation between unadjusted and adjusted ORs, researchers looked at the prevalence of atopic diseases in the migraine and control groups stratified by the presence or absence of corticosteroids. That analysis suggested that the association between migraine and asthma, allergic rhinitis, or allergic conjunctivitis was confounded by treatments.

Several mechanisms may explain the association between asthma or atopic disorders and migraine. One hypothesis points to allergens, the authors note.

"Investigators have speculated that inflammatory mediators released by mast cells during the allergic response may trigger migraine through the activation of trigeminal afferents," the authors write.

The association could also be independent of atopic mechanisms, involving inflammatory mediators, such as tumor necrosis factor-α and interleukin-1β.

Another possibility is that migraine is a side effect of allergy or asthma treatment. Antihistamine therapies may decrease histamine levels and inflammatory response.

Because the study was conducted in two European countries, its generalizability is increased, said the authors. But they can't exclude the possibility of recall bias for atopic diseases.

Children seen in the emergency department during summer months, as study patients were, may not represent all migraine occurring in children throughout the year. It's also possible that children with milder or less recurrent migraine don't come to the emergency department but instead see their family doctor, the authors speculate.

The authors also pointed out that they investigated the association between migraine and allergic rhinitis, not nonallergic rhinitis.

Obvious Bias

For a comment, Medscape Medical News called upon Jean-Christophe Cuvellier, MD, Service de Neuropédiatrie, Hôpital Roger Salengro, CHU de Lille, France. Dr Cuvellier has done research on pediatric migraine and has himself wondered about the well-documented connection between migraine and asthma/allergy.

He said he's "cautious" about drawing conclusions from the current study. For one thing, patients were seen only at tertiary care centers in large urban areas. "This is an obvious bias and I'm surprised that the authors don't even mention it."

Dr Cuvellier pointed out, as did the authors, that the study was conducted mainly during the summer, when air quality in cities such as Paris may be even poorer than usual.

"Robert-Debré Hospital is located in downtown Paris, a city so polluted that policymakers have had to issue regulations to curb traffic. As far as I know, Milan is also a polluted city, although I don't know about Udine."

While he said it would be "interesting" to conduct a similar study of patients in suburban and rural areas as well as in urban areas, Dr Cuvellier agreed with the authors that such a study would be difficult to carry out, "especially since there are so few child neurologists in France."

Both migraine and asthma are relatively common and the prevalence of both these conditions has been rising over the last few decades, mostly in urban and suburban areas, noted Dr Cuvellier. He wondered whether this holds true for allergic rhinitis, which might be more prevalent in rural areas.

"Ultimately, we'd like to find out the determinants of the high and rising prevalence of both migraine and asthma, and the reasons for their co-occurrence."

Dr Cuvellier found the percentage of males in the study's migraine group (almost 48%) somewhat high. "Due to the age at evaluation, one would expect a higher percentage of girls," he said.

"Are parents more likely to consult a doctor if their child is a male? Are general practitioners more prone to refer boys than girls? And if so, why?"

Dr Cuvellier also found the percentage of the migraine group with aura (35.8%) "rather high."

The authors have disclosed no relevant financial relationships.

Headache. Published online February 4, 2017. Abstract

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