Any skin condition of the face can also affect the eyelids. The skin of the eyelid is rather more loosely textured than that of the rest of the face, and therefore more liable to swelling. Blepharitis produces symptoms of redness and scaliness or crust formation; a chalazion is a painless swelling caused by blockage of a sebaceous gland in the eyelid. Sties are accumulations of fat in the skin of the upper or lower eyelid, taking the form of small yellow swellings. The eyelids are also prone to allergic reaction, in which the eyelid becomes red, swollen, painful or itchy. Entropion and ectropion are respectively outward and inward turning of the lower eyelid, usually in older patients. Swelling of the eyelids is often caused by inflammation somewhere in the region of the eye, such as sinusitis, a boil or inflammation of the tear ducts. Stings by insects such as midges, wasps or bees can also cause the loosely-textured tissue around the eye to swell. A cold, wet compress is usually adequate treatment.