If your rabbit develops itchy skin anywhere on their body, it's important to establish the underlying cause. Itching indicates inflammation in the dermal layers of your rabbit's skin, and if left untreated, your rabbit could develop a skin infection. Additionally, their secretory glands could be damaged as a result of sustained irritation, which could disrupt the production of oil that keeps your rabbit's skin and fur healthy. In addition to frequent scratching, your rabbit may lick or bite the area of skin that's itchy, and the skin may appear swollen or inflamed. Here's an overview of the causes of itching in rabbits:

Allergies

Your rabbit can develop food allergies or allergies to medication in the same way humans can. An allergy can develop at any time in a rabbit's life, and itchy skin is a common symptoms of allergies. Some rabbits are allergic to alfalfa hay, so if you suspect an allergy may be causing your rabbit's itching, changing the type of hay you feed them is a good place to start. Some antibiotics and non-steroidal anti-inflammatory drugs can also cause allergic reactions in rabbits, so if your rabbit is taking or recently stopped taking any medication, discuss the possibility of an allergic reaction with your vet.

Irritants

There are a number of potential environmental irritants that can cause your rabbit to experience itchy skin, such as cleaning products, cigarette smoke and dust. Strongly perfumed shampoos and scented bedding can also irritate your rabbit's skin. Try changing the products you use to clean your rabbit's living area, and if your rabbit is an indoor rabbit, avoid spraying chemical-based products, such as air fresheners or perfume, in the room you keep them in. Additionally, you should only use shampoos and soaps that are designed to be used on rabbits.

Parasitic Or Bacterial Infection

Parasitic infections from fleas and skin mites, such as encephalitozoon cuniculi, can cause itching, hair loss and crust formation around inflamed patches of skin. Bacterial skin infections also commonly occur when a rabbit has sustained a cut or graze, and the bacteria staphylococcus aureus is a common culprit. Your vet can easily determine if an infection is causing itchy skin by taking a skin cell sample for analysis. This will allow them to prescribe an anti-parasitic or antibiotic that's effective against the specific pathogen they have identified.  

If your rabbit is scratching frequently, or if you have any concerns about their skin health, have them examined by local veterinary services as soon as possible.