Skin changes such as rashes and bump under the armpit and on the leg next to knee are frequently the result of an allergy; however, this diagnostic possibility has to be confirmed by a dermatologist.





Pain in the shoulders and loss of strength in the forearms could be caused by spondylotic changes in the cervical vertebral column. An X-ray image of the cervical vertebral column is necessary to confirm or deny this possibility. You might seek help from your family doctor first, and then with an orthopedic specialist, neurologist, rheumatologist and/or dermatologist if necessary.