Start with your pediatrician who will get you into a derm if they feel you need one (if they cannot treat it). So many derms in the area have a weeks-long, if not months-long wait to get an appointment. If your pediatrician feels it's urgent, they will make a call and get you in.

As a pediatrician, I treated a subcutaneous hookworm in the sole of a little boy who picked it up on a Mexican beach. That was nasty -- you could see it under the skin. I did phone consult with an infectious disease specialist to make sure we got everything done that was needed.

Like this: http://en.goodtimes.my/2019/07/15/woman-gets-worm-infection-in-her-foot-after-walking-barefooted-on-a-beach-during-family-vacation-in-malaysia/

Dr. Abrams is very smart and great with children.

Was he barefoot on a beach or sandy pathway? It might be a rash but could possibly be hookworms. Specifically ask that the doc check for hookworms because of misdiagnosed or untreated they can cause serious problems and not all doctors will think "hookworm" if they see a rash or bug-bite-like symptoms. Google "hookworm beach couple 2018"--this story made a lot of people aware of how bad a hookworm infection from a Caribbean beach can be.

Is it a full-on rash or lots of little pinpoint bites?

If it's the latter, it may be from sand fleas.

Call your regular pediatrician, they should be able to treat it and if not they will refer you to a specialist

Looking for good pediatrics dermatologist in Chevy chase/dc - back from Mexico and child has rash on feet!!!