Persistent cold symptoms without nasal blockage for three months often suggest allergic rhinitis, non-allergic (vasomotor) rhinitis, or post-nasal drip, which can sometimes be triggered by acid reflux (GERD). If your main symptom is a lingering cough, it could also indicate cough-variant asthma. While over-the-counter antihistamines might offer temporary relief if allergies are the culprit, a three-month duration requires medical evaluation. I strongly recommend seeing an ENT specialist or an allergist. They may perform allergy testing or a nasal endoscopy to pinpoint the exact cause and prescribe targeted treatments.

Mouth breathing with a wheezing sound and disturbed sleep can be due to airway narrowing, often seen in conditions like Asthma, allergies, or a viral infection affecting the airways. Even without fever or daytime cough, nighttime symptoms can still occur. Monitor him closely, keep his room dust-free, and try steam inhalation if suitable. If the wheezing continues, worsens, or he has difficulty breathing, consult a doctor promptly, as he may need inhalation treatment or further evaluation.

Anti-inflammatory therapy is frequently required for a dry cough associated with allergic asthma and bronchitis, rather than only using a relief inhaler. Levolin provides immediate relief, but you could also require an allergy medication or steroid inhaler. See a doctor to modify treatment if the cough persists for more than a week or if breathing becomes more difficult.