Suggest Treatment For Itchy Brown Marks Spreading From Shoulders To Arm

Hi, My brother has a black or dark brown color mark which was very small we though it’s a spot but it’s now spread from the shoulder up to his arm. Its itching and growing- expanding and there are few tick hair growing on some side of that shoulder. We saw fee doc’s they said its skin fungal but after the treatments there is no change he is 22 now. Please advice what type of test can be done to find out the reason n treatment. Thank you