Severe dermatitis/ eczema only on hands.

My mother has severe red and white painful cracks on hands. Refer picture attached. Happens only on hands. Happens for 2,3 months in a year mostly during August September times. She has consulted various doctors but this is repeating every year during these months mostly. Please help me with any advise. Why is this repeating inspite of consultations. My mom's lifestyle is same everyday so why is it happening only during certain months? She does wash dishes with her own hands. Can this be the reason? But if thats the reason why is it happening only on certain months and not everytime? My mom has no diabetes, no high bp, has not hit menopause yet. Haemoglobin level falls a little low sometimes. Any specific tests required to diagnose this? What is this disease exactly called? She is currently using tablets - flax 369 and primosa. Do these medicines work for my mom's condition? Any other medication suggestions that can perform better? Thanks.