Thanks for the query.
Dents on nails and rash on skin might be suggestive of psoriasis
It is an autoimmune disorder.
A photograph would have helped me in giving a closer diagnosis.
Treatment can be with oral and topical steroids
may be required to confirm the diagnosis.
Please meet a dermatologist
for final diagnosis.
Let me know if you have any other doubt.
you can ask a direct question to me on this forum, following the below link.
Wishing you a good health.