Welcome to the Healthcare magic platform, Thanks for the query. Diclofenac sodium is a nonsteroidal anti-inflammatory drug (NSAID) which works by reducing pain and inflammation. Although rare, some individuals may show signs of allergic reaction with this drug. The reaction can present in various forms from mild to severe such as hives, rashes, sneezing, runny or stuffy nose,breathing difficulty or swelling of face, lips, tongue, or throat. I think that your friend is allergic to NSAIDs and therefore it is recommended that she immediately stop taking the medication and go for other alternatives such as acetaminophen (Tylenol) OR in case of severe pain consult rheumatologist for a better solution. As for Voltaren gel/cream, it contains the same active ingredient however, since it is only applied topically (on skin), the risk of developing serious side effects are comparatively low. Hope this answer is helpful. In case of further questions, you can ask without hesitation. Best regards, Dr. Khoja