Hello. Thank you for writing to us at healthcaremagic You have a condition known as post-inflammatory hyperpigmentation /PIH. It is hard to explain how a hair dye could cause pigmentation on wrist? Therefore I would like to keep another differential diagnosis of Fixed drug eruption (FDE). FDE presents as red colored or dark spots at various body sites in response to certain Oral medications like antibiotics, antiinflammatory, antiepileptics etc. The eruption is called Fixed Drug Eruption because each time the implicating drug is taken orally the eruption would appear at exactly the same sites Or would make previous spots darker. I suggest you to take a note of all the drugs that you have been taking or were taking for other illnesses like fever, flu, diarrhea, pain etc. I suggest you to visit a dermatologist in your region for a review of the diagnosis. Unless and until the implicating drug is identified and eliminated the spots would keep getting darker every time the drug is taken orally. Apart from avoiding the culprit drug, treatment of FDE is topical application of mid potent topical steroids e.g mometsone furoate 0.1% twice daily. Regards