Zyrtec (cetirizine) may be insufficient for angioedema, particularly if swelling is severe or interferes with breathing, but it can help minimize moderate allergic responses and itching. Angioedema can be fatal, so get emergency medical assistance and heed your doctor's advise.

Since your itching has lasted for three months and worsens at night, it is important to see a doctor for a proper diagnosis, as it could be due to eczema, scabies, or even pregnancy-related liver issues (if applicable). For temporary relief, you can apply an over-the-counter 1% hydrocortisone cream to the affected area twice daily. Taking an oral antihistamine like cetirizine (10 mg) once daily can also help reduce nighttime itching. Keep your skin well-hydrated with a fragrance-free moisturiser, use mild soaps, and avoid hot showers. Please consult a healthcare professional before starting any long-term treatment.

Limited improvement is anticipated because Zyrtec is an antihistamine and is not a conventional treatment for psoriasis. Topical therapies, phototherapy, or systemic drugs given by a dermatologist are the most effective ways to manage psoriasis.