Do i need to need to firstly see a gp and obtain a referral before visiting a dermatologist ?

Ask Benefits person: One can go to see a dermatologist without a referral unless one has a restrictive insurance plan (such as an HMO or a POS plan in the US) that requires a referral. If one has a PPO plan, a referral is almost never needed unless he has an uncommon, restrictive PPO plan that requires a referral. For better insurance coverage, one should see a dermatologist inside his insurance plan's network.