Arm pain feels like a red rash on the tendons inside, consider shingles, dengue and so on. Mainly drug treatment, to choose the appropriate drugs according to the cause of the disease. 1. Herpes zoster: herpes zoster can involve the skin and nerves, mainly the use of antiviral drugs, such as acyclovir, vasiclovir, etc., when the pain is significant, you can orally take acetaminophen and other non-steroidal anti-inflammatory drugs. Topical acyclovir ointment and other drugs can be used topically to promote the regression of skin lesions. 2. Dengue: Dengue is type B hemolytic streptococcus, staphylococcus aureus and other infections caused by the need for systemic medication, such as penicillin, cephalosporin and other antibiotics, the local magnesium sulfate and furacillin solution can be used wet compresses, and topical mupirocin ointment and other drugs. Arm pain accompanied by localized red rash should go to the hospital for a detailed examination, to clarify the specific causes of the disease, under the guidance of the doctor’s medication, not blindly use drugs.