It is very common for daily antihistamines like Allegra (fexofenadine) to cause dry nasal passages, which can lead to sinus irritation and a localized headache above your eye. Since your Covishield vaccine was a week ago, mild vaccine side effects would typically have resolved by now. The lack of relief from paracetamol and ibuprofen also points toward sinus pressure from dryness. Please try using a simple saline nasal spray to moisturize your nostrils and drink plenty of fluids. Since your headache is persistent, it is best to consult your doctor to rule out any other sinus issues or post-vaccine concerns.

Since cetirizine already provides you with excellent 48-hour relief, it is a highly effective choice, though it can occasionally cause mild drowsiness. If minimizing sleepiness is your main goal, fexofenadine (Allegra) is the best option among those you mentioned. Fexofenadine is highly effective for urticaria and is widely known as the least sedating antihistamine. In contrast, hydroxyzine (Atarax) is very sedating, and Montex FX contains a combination you may not need. I recommend discussing a trial of fexofenadine with your doctor to see if it keeps you comfortable and fully alert.

Since fexofenadine (Allegra) and Calsoft lotion aren't fully relieving the itch, your body is having a strong allergic reaction. Please stop using all sesame-containing products immediately. To soothe your skin right now, try cool compresses or a lukewarm bath. I highly recommend visiting a doctor promptly; they can prescribe a stronger generic antihistamine or a short course of oral corticosteroids to quickly calm the inflammation. If you experience any swelling of your face, lips, or difficulty breathing, please seek emergency medical care immediately.

Allegra 120 (Fexofenadine) is an antihistamine and can help relieve runny nose, sneezing, or allergy-related symptoms, but it will not reduce fever or headache from a cold. Since your cold has lasted 8 to 9 days with fever and headache, it is best to see a doctor.

Since fexofenadine (Allegra) hasn't helped, the symptoms might be caused by uncontrolled allergic rhinitis, post-nasal drip, or potentially cough-variant asthma. A pediatrician or pediatric allergist can help pinpoint the exact cause. They might recommend generic options like a nasal steroid spray or saline rinses to calm the inflammation, or evaluate him for asthma. I highly recommend scheduling a doctor's visit to help him finally get some restful sleep.

Since your symptoms return quickly after stopping deflazacort and fexofenadine, it is important to find a safer, long-term solution. Prolonged steroid use can have side effects. Under a specialist's guidance, next steps often involve increasing your daily non-drowsy antihistamine (like fexofenadine) up to four times the standard dose. If this is still ineffective, advanced therapies such as a targeted biologic injection (omalizumab) or other immunomodulating medications can be highly effective. Please consult an allergist or dermatologist to safely transition off the steroid and find a personalized treatment plan.