hello,
there are many causes for your mentioned symptoms, but I would like to mention the most common ones.
1. Vitamin B12 deficiency: This causes pigmentation over your hands as well as on your palmar creases. This is also associated with
symptoms of anemia also.
2.Addison's disease: here, the pigmentation is present on mentioned areas as well as oral pigmentation, pigmentation over light exposed areas, over friction affected areas. Along with this, there will be associated symptoms of fatigue,
hypotension, dizziness, loss of apetite,
abdominal pain and amenorrhoea.
3.Hyperthyroidism: Pigmentation is mostly like of addison's but
oral mucosa is not involved. there will be associated symptoms of high thyroid levels .
4. hereditary: this is mostly present from childhood and runs in family
Try to rule out these disease. In case if none of them are present, i would advise you to meet a
dermatologist in person
Thanks
Dr Jyoti Gupta