 [ Symptoms ] what are the ingredients in sulfamethoxazole trimethoprim [ Disease ] could also be nummular eczema ringworm is fungal and would need to be treated with an anti fungal to keep from worseningspreading nummular eczema is circular as well dry and itches like ringworm creams are available for treatment your regular doctor should be able to diagnose ringworm without referring you further to a dermatologist but might not be familiar with nummular eczema