Welcome to the forum. Hope you are following the doses of amitriptaline strictly as prescribed by your treating doctor. Do not take over doses.Over dose has many adverse effects one of it is drying of the skin.
The blisters in your palms can be on account of it. The blisters and itch can also be due to some strong washing soap or lotion that you might have used in either your kitchen or while washing hands or clothes. Your skin has reacted to harsh chemicals used.
You should apply a light medicated lotion/calamine
lotion/lotion that best suits you, onto your palm and avoid handling water for at least 2 hours after application. You should also apply it at your bed time. You can see a dermatologist
if you feel its still troubling you much.You can take vitamin food rich in vitamin B and E. You can also take its supplements. Sometimes it can be due to vitamin deficiencies in your body.
Use gloves for better healing. Enjoy good health, take care.