The anterior nares are the external (or "proper") portion of the nostrils (nose). The anterior nares opens into the nasal cavity and allow the inhalation and exhalation of air. Each is an oval opening that measures about 1.5 cm anteroposteriorly and about 1 cm in diameter.
The anterior nares are commonly infected by Staphylococcus aureus (also known as "golden staph") which may contribute to dermatitic skin lesions in patients with atopic dermatitis. The anterior nares can act as a colonizing point from which the infection can spread to other areas (and they should probably be checked in the case of a recurring staph infection). This can be particularly troublesome if the strain is an antibiotic resistant (commonly MRSA or ORSA) strain. MRSA (first discovered in the UK in 1961) has become particularly widespread in hospitals and is commonly considered a superbug. For more information on symptoms and treatment see MRSA.