thank you for your query . The rashes that your mother developed over her back is not did to the mesh used during inguinal hernia repair
. It is probably an allergic reaction
developed post surgery following certain medications or the use of the plaster over the back following spinal anesthesia
, I would suggest you to use antihistamines to reduce the itching along with calamine lotion . You can also get a consult with a dermatologist
if it worsens .