I am experiencing a fungal infection near my neck and breast area. It started with mild itchiness, but over time the affected area has developed dark patches. The itching is still mild, but the pigmentation is increasing and causing concern. I would like to know the possible treatment options and how this condition can be cured completely. Please also advise if any tests, medications, or topical treatments are required, and whether there are specific precautions related to hygiene, clothing, or diet that I should follow.