If your child has had a cold for 10 days and symptoms keep returning despite Delcon Plus, it may be due to a persistent viral infection, allergy, or even sinus involvement. Continue supportive care like warm fluids, steam inhalation (if age-appropriate), and saline nasal drops. Avoid frequent use of cough syrups without advice. If there is fever, thick nasal discharge, cough worsening, or no improvement, consult a pediatrician for proper evaluation and treatment.