What causes petechial spots after scratching on arms?

Brief Answer: Due to bleeding disorder. Detailed Answer: Hello, Thanks for trusting us with your health concern. Development of petechial spots after scratching on the arms is suggestive of a bleeding disorder. In your case, myeloma seems to be the most likely cause. You need to consult your physician to get a complete blood coagulation profile checked with APTT and platelet count to rule out the possible causes like thrombocytopenia. This can also happen due to a viral infection in the recent past- decreases the synthesis of platelets from the bone marrow. Presence of any autoimmune disorders also needs to be ruled out. The treatment is based on the diagnosis and severity of the problem. Treatment is usually done by fluid infusion, steroids, immunoglobulins, blood transfusions, etc according to the severity of the condition. Please feel free to discuss further. I will be glad to answer the follow up queries that you have. Wishing you good health. Regards. Dr. Rakhi Tayal. For future query, you can directly approach me through my profile URL http://bit.ly/Dr-Rakhi-Tayal