U.S. doctors online nowAsk doctors free
A 27-year-old male asked:

My son has a rash on his arm that looks like a bruise and has a lump right in the middle of it?

2 doctor answers4 doctors weighed in
Dr. Anthony LaBarbera
Dr. Anthony LaBarberaanswered
Pediatrics 30 years experience
See below: The lump can be do to the trauma that caused the bruise. I would not be concerned, unless your son starts developing bruises without trauma.
Created for people with ongoing healthcare needs but benefits everyone.
Dr. Cheryl Coldwater
Pediatrics 40 years experience
Hard to say: It's extremely difficult to identify rashes from a description on the internet. See your son's doctor so he/she can tell if it is something to be concerned about.
Created for people with ongoing healthcare needs but benefits everyone.
Last updated Sep 28, 2016

Disclaimer:

Content on HealthTap (including answers) should not be used for medical advice, diagnosis, or treatment, and interactions on HealthTap do not create a doctor-patient relationship. Never disregard or delay professional medical advice in person because of anything on HealthTap. Call your doctor or 911 if you think you may have a medical emergency.