Hello,
It can be due to contact dermatitis, allergies or pompholyx. Pompholyx primarily involves the hands and fingers and then may involve the feet. The first stage is acute and presents as itchy blisters on the hands, fingers and toes. Then the chronic stage shows more peeling, cracking, or crusting. Apply some calamine lotion on the affected area and keep the area well moisturized. Use only thin applications of moisturizer ointments as excessive amounts of ointment may restrict breathing of the skin and aggravate the condition.
Topical steroids can be applied but they are available under prescription. Moreover to prevent infection, topical antibiotics may be needed. I suggest you to consult a dermatologist and get it evaluated.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
i should note that I have some small clear pustules on the hands whilte the rash under the armpit and the arm looks like acne