Painful cluster rashes on the upper arm. Cause?
Patient: On Saturday, I went to Catalina Island on a ferry...and on the way back home, i noticed a rough cluster of rash like bumps on my inner upper arm. They are quite painful (not excruciatingly) and have now formed black dots in the middle of the bumps. The pain is still there. What might this be? I dont remember being bitten by any insect or anything...and i cannot think of anything that may have caused it Doctor: Hi,    Clusters of bumps on your skin can be alarming , as bumps may be a sign of an infectious or allergic process going on your body.  Skin infection can also occur due to any reason.      The bumps are due to either allergic reaction to something or infection in skin.      The reason for allergy could be any substance which comes in contact frequently, may some cream or chemicals etc,      Itching leads to damage the layer of the skin and leaves a scar.    Apply Dhurva thailam daily.