The International Study of Asthma and Allergies in Childhood (ISAAC) Phase One showed large worldwide variations in the prevalence of symptoms of asthma, rhinoconjunctivitis and eczema, up to 10 to 20 fold between countries. Ecological analyses were undertaken with ISAAC Phase One data to explore factors that may have contributed to these variations, and are summarised and reviewed here.In ISAAC Phase One the prevalence of symptoms in the past 12 months of asthma, rhinoconjunctivitis and eczema were estimated from studies in 463,801 children aged 13 - 14 years in 155 centres in 56 countries, and in 257,800 children aged 6-7 years in 91 centres in 38 countries. Ecological analyses were undertaken between symptom prevalence and the following: Gross National Product per capita (GNP), food intake, immunisation rates, tuberculosis notifications, climatic factors, tobacco consumption, pollen, antibiotic sales, paracetamol sales, and outdoor air pollution.Symptom prevalence of all three conditions was positively associated with GNP, trans fatty acids, paracetamol, and women smoking, and inversely associated with food of plant origin, pollen, immunisations, tuberculosis notifications, air pollution, and men smoking. The magnitude of these associations was small, but consistent in direction between conditions. There were mixed associations of climate and antibiotic sales with symptom prevalence.The potential causality of these associations warrant further investigation. Factors which prevent the development of these conditions, or where there is an absence of a positive correlation at a population level may be as important from the policy viewpoint as a focus on the positive risk factors. Interventions based on small associations may have the potential for a large public health benefit.

Little is known about the effects of exercise on the sensory and cognitive aspects of coughing evoked by inhalation of tussigenic agents. The threshold for the cough reflex induced by inhalation of increasing nebulizer outputs of ultrasonically nebulized distilled water (fog), an index of cough reflex sensitivity, was assessed in twelve healthy humans in control conditions, during exercise and during voluntary isocapnic hyperpnea (VIH) at the same ventilatory level as the exercise. The intensity of the urge to cough (UTC), a cognitive component of coughing, was recorded throughout the trials on a linear scale. The relationships between inhaled fog nebulizer outputs and the correspondingly evoked UTC values, an index of the perceptual magnitude of the UTC sensitivity, were also calculated. Cough appearance was always assessed audiovisually. At an exercise level of 80% of anaerobic threshold, the median cough threshold was increased from a control value of 0.73 to 2.22 ml/min (P<0.01), i.e., cough sensitivity was downregulated. With VIH, the threshold increased from 0.73 to 2.22 ml/min (P<0.01), a similar downregulation. With exercise and VIH compared with control, mean UTC values at cough threshold were unchanged, i.e., control, 3.83 cm; exercise, 3.12 cm; VIH, 4.08 cm. The relationship of the fog nebulizer output/UTC value was linear in control conditions and logarithmic during both exercise and VIH. The perception of the magnitude of the UTC seems to be influenced by signals or sensations arising from exercising limb and thoracic muscles and/or by higher nervous (cortical) mechanisms. The results indicate that the adjustments brought into action by exercise-induced or voluntary hyperpnea exert inhibitory influences on the sensory and cognitive components of fog-induced cough.

Chronic obstructive pulmonary disease (COPD) is common in older people. Inhaled medications are the mainstay of pharmacological treatment of COPD, and are typically administered by handheld inhalers, such as pressurised metered-dose inhalers and dry powder inhalers, or by nebulisers. For each of the three major categories of aerosol delivery devices, several new inhalers have recently been launched, each with their own particularities, advantages and disadvantages. Consequently, broader availability of new drug-device combinations will increase prescription opportunities. Despite this, however, there is limited guidance available in published guidelines on the choice of inhalers, and still less consideration is given to elderly patients with COPD. The aim of this article is to provide a guide for healthcare professionals on device selection and factors to be considered for effective inhaled drug delivery in elderly COPD patients, including device factors (device type and complexity of use), patient factors (inspiratory capabilities, manual dexterity and hand strength, cognitive ability, co-morbidities) and considerations for healthcare professionals (proper education of patients in device use).

Cough is defensive airway reflex subjected to a high degree of cortical control. Not surprisingly, all cough motor patterns can be mimicked and reflex cough be inhibited up to complete suppression, at least to a certain extent. Reflex cough differentiates from other airway reflex responses for its characteristic 3-phase motor pattern, and such pattern is maintained when coughing is produced voluntarily. Despite these and some other similarities, voluntary and reflex cough differ in many important respects, suggesting different neural control of the respiratory and non-respiratory musculature implicated in the generation of the cough modalities. This paper focuses the motor features that differentiate voluntary and reflex cough efforts, and highlights the importance of functional assessment of coughing in the diagnostic workup of respiratory and extra-respiratory diseases affecting the production of voluntary and reflex cough.

Chronic cough has been reported to be the fifth most common complaint seen by primary care physicians in the world, the third in Italy. Chronic cough in non-smoking, non-treated with ACE-inhibitor adults with normal chest radiogram could be a symptom of asthma and can be sub-classified into: cough-variant asthma, atopic cough, and eosinophilic bronchitis. This review discusses the differential diagnosis of these three disorders.