**8. Differential diagnosis based on the dominant symptoms**

Many processes that start at preschool age manifest similar symptoms to those of bronchitis or asthma. The too early start of these symptoms, sometimes shortly after birth or in the first months of life, is a matter of warning about the possibility of a process less frequent than those, but even if the process has a late start, the other possible causes of cough or dyspnoea should never be forgotten, avoiding the comfortable position of starting a routine treatment, which may not always be beneficial and could even delay the establishment of appropriate thera‐ peutic measures.

The assessment of cough as a symptom, that in the case of asthma is often maintained between the crises of dyspnoea or wheezing, has some characteristics that can guide to others diagnosis not uncommon at preschool age, with symptoms that may be common to those of asthma, and therefore is mandatory to take them into account in order to conduct a correct differential diagnosis (**Table 4**).


**Table 4.** Most significant processes in the differential diagnosis.
