Homoeopathy is synonymous to Hyposensitization or Desensitization. In Asthma, Patient is suffering with individual over sensitivity and what we need is desensitization or Hyposensitization to get rid of symptoms and disease as a whole. For Hyposensitization Homoeopathic medicine should have minimal quantity of similar drug substance and the medicine should not be deprived of the basic crude drug substance.
It does not mean that Homoeopathic medicines in higher dilutions do not work in Asthma cases. Constitutional Homoeopathic medicine in higher potencies improves or modifies the susceptibility of Sick, Means it reduces the tendencies of a living being to be over effected by certain things which can hardly make any impression in other healthy living being.
For the development of Asthma and other sickness there must be more than one cause such as genetic tendencies, thermal telluric chemical biological injuries, environmental pollution, faulty unnatural living habits etc. Each of above factors needs special attention in Asthma and other diseases to attain total cure or maximum amelioration of symptoms.

In case of respiratory tract allergy you must note following points:

1.  Avoid exposure to exterme variation of temperature in all conditions, Use nothing hot in cold weather and nothing cold in hot weather. Variation of more than 20 degrees centigrade of Temperature causes immunological injury to life force and causes over-sensitisation of living being. Due to this over-sensitisation, body over-reacts to allergens (which can hardly make any impact on normal human being otherwise) and results in allergic diseases like sneezing and running nose etc.

2.  Avoid Rice (in Northern Planes of India and Pakistan), Banana and Colocassia (Arvi).

3.  Regular symptom limited exercise is must (As per age of Patient).

4.  Avoid all Pain Killar and fever pills such as Salicilic Acid (Aspirin-Disprin), Paracetamol (Crocin), Nemuselide (Nemulid, Nice), Ibuprofen (Brufen, Combiflam etc.). All such type of medicines causes bronchospasm (constriction of air passage) and lead to asthma.

5.  Slight running nose and sneezing  in asthmatic patients ameliorates their difficulty in breathing. Do not suppress unneccessarily these sign and symptoms.