Hello,
I cannot confirm anything without examination but it can be due to eczema or contact dermatitis. Wash the areas several times with fresh water. Do not use any cosmetic products at the sites. You can apply some calamine lotion at the rash as it will help in soothing the skin. You can take some OTC oral antihistamine medications like Benadryl or Claritin and see if it helps.
For mild-moderate symptoms a weak steroid may be used , whilst more severe cases require a higher-potency steroid. Use good quality moisturizers to prevent moisture loss from the skin. At night, repair them with creams formulated from glycolic acid—a must for improving skin texture and tone. For a more intensive nighttime treatment, apply cream and then cover hands with gloves or socks. I would also suggest you to avoid washing hands with soap repeatedly and use gloves while doing any household work. If still the symptoms do not improve then please get a clinical examination done by a dermatologist.
I hope it helps. Take care and please do keep me posted in case you have any additional doubts. Kind regards.
It was terrible and my thumb itch whole day.