Asthma and allergic rhinitis may predict migraines in adolescents, according to a recent population-based study published in The Clinical Respiratory Journal.
“Although asthma is a respiratory disorder and migraine is a neurologic disorder, the question of their relationship has fascinated allergists and neurologists for more than a century,” wrote authors, led by Yael Graif, MD, Allergy and Immunology Clinic, Pulmonary Institute, Rabin Medical Center–Beilinson Hospital, Petach Tikva, Israel. “Indeed, asthma has been previously described as ‘acephalic migraine’ and ‘pulmonary migraine.’”
Previous population-based studies, primarily in adults, have documented a significant link between asthma and migraine.. A study involving US adolescents suggested a physical comorbidity between migraine and inflammatory conditions, and a significant association between migraine and heightened frequencies of asthma and seasonal allergies.
In the current case-control, retrospective study, the team mined recruitment data from 1987 to 2010 to create a cohort of 113,671 adolescent Israeli army draftees, aged 17 years old (army service is mandatory in Israel for all 17-year-old citizens of both genders). Asthma and migraine diagnoses were made by specialists.
Dr. Graif and colleagues assessed the prevalence of migraine among draftees both with and without asthma. They also identified sociodemographic and comorbidity covariates and performed a multivariate analysis controlling for these confounding variables.
In all, 4.0% of subjects had asthma and 1.9% had migraine. Importantly, migraine was more common among subjects with asthma than in those without asthma (3.8% vs 1.8%, respectively; OR: 2.17, 95% CI: 1.86-2.55; P < 0.001). Additionally, the frequency of migraine among subjects with allergic rhinitis was 6.3% compared with 1.7% in those without allergic rhinitis (OR: 4.04; 95% CI: 3.58-4.56; P < 0.001).
Upon multivariate analysis, Dr. Graif and fellow researchers found that the association between migraine and asthma or allergic rhinitis persisted, although it was somewhat attenuated by confounding variables (asthma OR: 1.42, allergic rhinitis OR: 3. 18).
Significant covariates included the following:
- Female sex
- Urban vs rural residence
- Recent immigration to Israel
- Having ≤ 3 siblings
- Abnormal body mass index (BMI)
Overall, the team estimated that the adjusted relative risk of migraine diagnosis among Israeli adolescents with asthma was 1.42. This result concurred with previous research findings from the United States, United Kingdom, Norway, Taiwan, and Turkey. Furthermore, on the basis of their previous research, Dr. Graif and colleagues posited that the majority of subjects with asthma had allergic asthma.
The potential mechanisms that connect asthma, allergic rhinitis, and migraine have yet to be elucidated. The researchers suggested that mast cells may play a role in all three conditions. These cells produce proinflammatory mediators, such as histamine, prostaglandins, and tryptases, which contribute to allergic disease. Mast cell degranulation also triggers a pain pathway in migraine.
Due to the cross-sectional design of the current study, the team could not determine the temporal link between asthma and migraine. Nevertheless, on the basis of previous research, they suggested that migraine diagnosis followed asthma diagnosis.
“Clinicians should be aware that asthma and allergic rhinitis are potential risk factors for migraine in adolescents. A combined finding of these conditions and recurrent headache is highly suggestive of migraine and warrants a different diagnosis and treatment approach from sinusitis,” concluded the authors.