Opinions/Hypotheses

Rhinosinusitis and Asthma: Epiphenomenon or Causal Association?

Our understanding of the relationship between the upper and lower airways has greatly increased as a consequence of epidemiologic and pharmacologic studies. A consistent body of scientific evidence supports the concept that rhinitis, rhinosinusitis and asthma may be the expression of a common inflammatory process, which manifests at different sites of the respiratory tract, at different times. This paradigm states that allergic reactions may begin at the local mucosa, but tend to propagate along the airway. Central to the allergic diathesis is the eosinophil and its interaction with the airway epithelium. The implications of the interplay between upper and lower airway are not only academic, but also important for diagnostic and therapeutic reasons. Furthermore, there is significant overlap in symptomatology and pathophysiology for childhood sleep disordered breathing (SDB) and asthma. Recent evidence supports an association between these two conditions, but causality has not been demonstrated. Regardless, it is important to recognize the overlap and evaluate for the other condition when one is present. In children with poorly controlled asthma, the presence of SDB may significantly contribute to asthma morbidity and, as such, should be actively excluded. On the other hand, clinical evaluation for asthma should be considered in children with SDB.

Future robust longitudinal research is needed to explore the association between upper and lower airway diseases using objective measures in children.

Most pediatric asthma is easily treated with low-dose inhaled corticosteroids, occasionally combined with a long-acting bronchodilator, provided the medications are administered regularly and correctly. If the child does not respond to treatment, rather than escalating treatment uncritically, a detailed, protocolized assessment is mandatory. This should include a review of the diagnosis and assessment of the presence or otherwise of any extrapulmonary comorbidities, such as obesity, exercise-induced laryngeal obstruction and lifestyle and social factors, such as adherence, perhaps the most important cause of “treatment resistant asthma,” and allergen and tobacco exposure; this enables successful management of 90% of referrals with apparent severe asthma. For the rest, bronchoscopic assessment of airway pathology is advisable, combined with a parenteral steroid trial, to deconstruct airway pathology by determining the presence and nature of any inflammation and whether there is fixed airflow obstruction. If inflammation is present, it is eosinophilic not neutrophilic but signature T-helper cell cytokines are difficult to detect, suggesting alternative pathways are important. There is no agreed upon pediatric definition of steroid responsiveness, and we advocate a multidomain approach. Other than for omalizumab, treatments for steroid-resistant asthma have no evidence base in children. The child with recurrent asthma attacks is particularly difficult to manage and is at high risk of further attacks and death from asthma. In summary, therapy-resistant asthma is rare but a really difficult problem when present. Most apparent therapy-resistant asthma can be successfully treated by optimizing basic management, especially ensuring adherence to standard therapy.

Los pacientes asmáticos severos corresponden a un grupo heterogéneo de individuos que requieren tratamientos múltiples para lograr el control de su enfermedad. Quienes tratamos a estos pacientes con asma severa, nos enfrentamos a un grupo seleccionado de niños que no permiten establecer conductas homogéneas en su manejo y que determinan enormes costos en salud y una gran carga emocional para ellos y su familia. El enfrentamiento en forma estandarizada de estos pacientes, actualmente llamados problemáticos, permitirá diferenciar a los asmáticos catalogados como de difícil manejo de aquellos verdaderamente severos.

El siguiente artículo tratará de ayudar al clínico a ordenar los conceptos claves para orientar una toma de decisiones más racional y acorde a los conocimientos actualizados.

The most severe asthmatic patients belong to a heterogeneous group of individuals who require multiple treatments to achieve control of there disease. Those who treat patients with severe asthma, are faced up to a selected group of children that do not allow us to establish regular conducts in there treatment, and determine high costs in health and a big emotional burnout not only to the patient but to the family as well. The way to treat these patients that are actually called “problematic” will help us differentiate and cataloged the difficult patients with the real severe ones.

The following article will try to help the clinicians order the key concepts to guide a more rational decision according to their updated knowledge.

Asthma in childhood is a huge subject, and this chapter is therefore perforce selective in the coverage of the subject. The most important precept is not to be tempted to extrapolate from adult studies into childhood, and still less into the preschool years. It is increasingly recognized that medicines used in children must be tested in children; the disease may be different, pharmacokinetics may be different, and the risk profile is different. Events prior to birth and during infancy are pivotal in determining long-term lung health, a fact under-recognized in many adult respiratory textbooks. The obvious targets for chronic obstructive pulmonary disease (COPD) susceptibility have long been genes related to protection against oxidative stress, and those related to inflammatory pathways. The ideal method of sorting out the effects of early influences on adult disease would be to recruit a large cohort of babies antenatally, preferably preconception, and follow them through until death, making measurements of lung function, airway pathology, infective agents and environmental exposures, both indoor and outdoor. There are two indications for treatment, the immediate relief of symptoms and the prevention of disease progression, in the case of the preschool child from intermittent to continuous symptoms. Those who have survived a sudden and severe attack may be considered for pre-packed, injectable adrenaline. Of course, most children have sufficient time to use inhaled therapy, but for those with really sudden deteriorations may anecdotally benefit from this approach. The other scenario is the child with deteriorating asthma who is unable to recognize that things are getting worse, until a late, catastrophic decline ensues. Failure of perception is therefore a mimic of acute rapid deterioration.