Hello, Dry cracked itchy patch of skin on the knee caps commonly occur due to allergy, atopic / contact dermatitis, psoriasis, eczema, etc. You are suggested to drink plenty of water, keep yourself well hydrated. Cut on addictions if any. Do not take food that triggers skin allergy. You can take non sedating antihistamines to reduce itching. Take care of your hygiene. Do not let the area affected get infected. Do not scratch or touch. After a shower you can apply ointment hydrocortisone to ease itching. You are suggested to get clinically examined by a dermatologist, get tested so that treatment can be started at the earliest. Your treating dermatologist may recommend Ultraviolet light treatment or phototherapy in severe or chronic case. If psoriasis and eczema is diagnosed you will be treated with topical cortisone or immunosuppressive medicines. In the meantime, keep your knee skin well moisturized, do not let it get dry. Use humidifier, wear soft cotton clothes. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician