Dear Chris & Sarah,
Thank you for your consult at DoctorSpring.com, I can understand your concerns. A cough that persists for 3-4 weeks can be really challenging to diagnose as well as manage. I can only imagine what you must be going through.

The site of problem appears to be the child's airway (In medical terms, trachea/bronchi/ bronchioles).

With the information provided by you, it does appear that there are increased secretions in the upper airway (throat/ respiratory tract). This is suggested by the rattling that you could hear intermittently. In children, the cough is not powerful enough to bring out the mucus/increased secretions. The steamy shower and the humidifier probably help by decreasing the airway edema and secretions.

Before, I can help your daughter, I need to know the answers to the following queries
1. Does she have any episodes of noisy breathing/ wheezing (whistling noise while breathing out) ?
2. Does she have any diurnal or postural variation in cough ? Does she seem to cough more during any particular time of the day ? Is there any relation with being in upright position or lying down?
3. Is there any relationship of the cough with feeding or swallowing?
4. Does she have any past history of skin allergy, allergic rhinitis, atopic dermatitis or asthma? Is there any such history in the family?
5. What is her weight and height? How is her appetite?
6. Did she have any episode of respiratory tract infection (fever, cough, nasal congestion or rapid breathing) prior to the onset of this lingering cough?

Look forward to your reply.
Regards
Dr. Saptharishi L G
DM (Pediatric Critical Care)
MBBS, MD (Pediatrics), PGDCRL
Advanced Pediatrics Center
Post-Graduate Institute of Medical Education & Research

Dear Chris & Sarah,
Thank you for answering those queries, It has helped me understand the situation better. The description would fit into a 'post-viral bronchitis/ post-viral cough'.
Many viral infections leave some amount of inflammation/injury in the large airways called the bronchi. The bronchial lining (ciliary epithelium, that moves the mucus out of the lungs) is damaged during the infectious episode. These bronchi are unable to clear out the mucus and become filled with gooey secretions. This may take weeks to heal. There is also a component of BRONCHOSPASM that exists as a reaction to the infection/mucosal injury. This manifests as post-viral cough in the child. It is a very common concern.
As for as management of this condition is concerned, there are no proven strategies.
In most children, the following measures help:
1. Cough suppressant syrups/ expectorant syrups. MUCINEX is not something that I am comfortable with. In fact, not very commonly used in children. It contains ingredients that may be harmful to kids less than 12 years old. I prefer syrup HONITUS (if it available in your locality)
2. Bronchodilators - In your child's case, it may help. We can try: Syrup ASTHALIN 4 ml thrice daily for 5 days and see if she has any improvement in cough.
3. Avoid cold drinks/ ice creams/ chilled food-items. Ingestion of cold food can further decrease ciliary motility and worsen cough. Give her only luke-warm water to drink.
4. Avoid spicy foods. Give her bland, easily digestible food for a few weeks.
5. Can use steam inhalation/ humidification if it helps her
Wishing your child a speedy recovery.
Regards.

Dear Chris & Sarah,
The generic name of asthalin is SALBUTAMOL. It is available in all countries. The dosage is 0.15 mg/kg/dose three times a day for three-five days.
The alternate for HONITUS is CHESTAL cough syrup. Basically, it is a honey containing preparation that acts as a lozenge and suppresses cough by soothing the throat.
Regards.