Hello,
Without examintion,confirmation of a diagnosis is tough,but there are various possibilities for your symptoms.It can be due to allergic contact dermatitis,atopic dermatitis,sweat dermatitis,candida infection,peripheral nerve damage,neurodermatitis and obstructive biliary disease. Internal diseases like liver and kidney disorders,diabetes, iron deficiency anemia, irritation and allergic reactions tochemicals,wool,soaps,cosmetics and certain foods can cause itchy underarms.