A rash on my shoulder 1st appeared as 1 sml quarter sized area i used benadryl (diphenhydramine) cream & it made it worse. it's now 3 in diameter & there are 3 spots.

About time see MD: You have a rash which is spreading and your own home treatment with Benadryl (diphenhydramine) cream is ineffective and it is spreading i think it ia about time you see your doctor or a dermatologist to find the cause of your rash it needs to be checked as there are several possibility like impetigo, fungus infections and others.

Skin rash: Would suggest evaluation by your family doctor or a dermatologist to make the appropriate diagnosis and recommend treatment.

Unclear question.: If you have a dog, you might have caught a skin fungus from it. But your question is so vague that it is hard to give a good answer.