Chronic itching around the anus, especially when it persists for several months and begins affecting both sides, can be caused by various factors such as dermatologic conditions (e.g., eczema, psoriasis, or fungal infections), haemorrhoids, anal fissures, intestinal infections, poor hygiene, or allergic reactions to products. Given that your symptoms have lasted for 10 months and are spreading, it's important to consult a healthcare provider for a thorough evaluation. A physical examination and further tests are necessary to identify the underlying cause and determine the most appropriate treatment, as self-diagnosis and over-the-counter medications may not address the root cause and could worsen the condition.

Clean the bite gently with soap and water, apply an antiseptic, and keep it covered. Take a painkiller if needed and watch for redness, swelling, or pus. Inform a doctor if it worsens or if signs of infection appear.