Itching and color changes in the penis and testicles can be signs of irritation, infection, or an allergic reaction, which may or may not be related to your use of Xyzal (levocetirizine). While Xyzal is an antihistamine used to treat allergies, it can sometimes cause skin reactions, but these symptoms should be evaluated to rule out other causes like fungal or bacterial infections.

• Monitor for worsening symptoms such as increased redness, swelling, pain, discharge, or fever.
• Avoid scratching to prevent further irritation or infection.
• Maintain good hygiene and use gentle, fragrance-free soaps.
• Since these symptoms involve sensitive areas and could indicate an infection or allergic reaction, it is important to see a dermatologist or a urologist promptly.
• If you experience severe pain, swelling, or systemic symptoms like fever, seek emergency care immediately.

Consulting a specialist will help determine the exact cause and appropriate treatment. If you want, I can explain more about possible causes or treatments.To narrow down potential causes, we will need some more information.I understand that you're concerned about the color change and itchiness of your penis and testicles, especially since you're taking Xyzal. To assist you better and provide relevant guidance, could you please share your age and gender?