Geoff Noake and daughter Amy Helliwell, who lives in Dinnington, run a business in Eckington that is looking after the marketing and social media for the campaign.
Ms Helliwell’s son Max, aged seven, has Congenital Melanocytic Naevus, CMN, on his head and has to be regularly monitored in hospital.
She said: “Not many people know about CMN so it’s an important campaign to support and raises awareness. It means a lot to me because of Max.
“It’s quite rare and can cause problems if it grows on the spinal cord and bones, which is why Max has regular check ups in hospital.
“The response to the exhibition on social media has been fantastic - I’m really proud to be working on it.”
The collection of photographs called ‘How Do You C Me Now?’ features 30 children and adults from across the world born with the rare skin condition which can be life-threatening in some cases.
Photographer Brock Elbank took the pictures, and those photographed said they had never revealed their birthmarks publicly before.
It launches in London on Wednesday, March 13 at the Oxo Tower Wharf and will be open to the public until March 24.