Red/Black Spots on Lower back

Can anyone please recommend a private dermatologist to me?

I would like to seek some opinion about a strange worsening skin condition and my GP has been reluctant to treat or refer. He has told me that this is permanent.

I am a 28 yr old married lady , not on oral contraceptives. The rash (shown in pictures below) started in February . It started with a pink-red firm papular rash which then turns black (pigmented) and remains so. Over the last 10 months, new lesions have continued to appear and gradually moving upwards on my lower back. the rash is pruritic when pink-red papules start to dry into black. No fever or any constitutional symptoms at any stage.

I have no previous history of this. Have  had  acne on face and upper back which responded to retenoic acid and were fully resolved  in 2010 . I am allergic to imitation jewellery. No history of having worn same in the period rash appeared. Also allergic to tetanus injection.  

GP prescribed Erythromycin orally and zinc ointment without any response. I have stopped using all soaps, body cosmetics, fabric conditioners since 3 weeks with no response.


3 pictures of rash attached if anybody wants to take a guess at what this might be?

Please Help.