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.

Both fexofenadine (Allegra) and levocetirizine (Teczine) are generally considered safe during breastfeeding because only tiny amounts pass into breast milk. However, taking Allegra 180mg twice daily alongside Teczine 10mg is a very high combined antihistamine dose. While generally safe, such high doses can occasionally cause mild drowsiness in your five-month-old or slightly decrease your milk supply. Please monitor your baby for any unusual sleepiness or changes in feeding. I highly recommend consulting your doctor or pediatrician to confirm if this combined dosage is necessary or if a lower, safer dose would successfully clear your rash.

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.

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.

Itching with rashes and redness all over the body may indicate an allergic reaction, infection, or skin condition. You should consult a dermatologist for proper evaluation and, in the meantime, avoid scratching, use gentle skin care, and keep the skin moisturised.

Red rashes with itching after fever and medicines may be due to a drug reaction or a viral rash. This should not be ignored, as some reactions need prompt medical attention. Avoid taking any new medicines without medical advice. Consult a doctor immediately for proper evaluation and suitable management.