Greetings. Well as per your description.... Madam the swelling need not be from skin alone and there are situations when a swelling forms below the arm pit region. I would be happy to guide you further. It could be something thats should be checked and treated at the earliest. You can contact us at Health Cottage Hospital, Bangalore. REGARD & GOOD LUCK.
Thanks for the query.
This presentation can be seen with many diseases. This is limited information to make precise recommendations. The best option is to consult a Dermatologist to understand the condition. A thorough evaluation if necessary should be done. Hope it helps you.
Meet a Dermatologist and discuss the situation, If needed a skin biopsy can be done to achieve a final conclusion.
Your dermatologist will decide a treatment plan for you after a consultation.