From the information that you have given it looks like you are having contact dermatitis
are made of different materials and this can cause contact dermattitis.Sometime the dust and the dustmites settled on it can also cause allergic reaction
Along with the hydrocortisone cream
,you will also require antihistaminic tablets to relieve your itching.You can try using calamine lotion for the soothening your skin.
Hope it helps,