Stop it...You are suffering from irritant contact dermatitis due to pain balm.. Medicine available for good improvement......As the treatment varies depending on the severity... Send photos of the affected area, by direct online consultation for accurate diagnosis and treatment.

Pain relief balms often have irritants which cause dermatitis. Furthermore, considering your age, your skin's barrier function would have become impaired allowing for deeper penetration of such topical medicines. Same balms contain eucalyptus oil which can cause seizures if too much is absorbed systemically. Keeping all these points in mind, I recommend you stop the use of the pain relief balm. For back pain, it is better to consult a certified orthopedic doctor. As for the irritated skin lesion, kindly send some photographs to me via direct online consultation or visit a certified dermatologist near you for detailed treatment options.