Small nodules on the eyelids can be caused by a variety of inflammatory diseases, such as painful localized redness of the eyelid skin, usually due to blepharitis, or pus-like nodules on the eyelids due to bacterial infection of the eyelid skin. It can be caused by allergies and usually appears as an edema or lump on the eyelid with significant itchiness and is not painful to touch. It can also be caused by a lid cyst, which appears as a small, non-red, non-painful nodule on the eyelid skin. If a small yellow nodule appears on the outside of the skin on the inside of the upper eyelid, it is common in middle-aged and older patients and may be a yellow tumor. Alternatively, nodules on the outside of the eyelid skin may be caused by various eyelid tumors, such as pigmentomas, hemangiomas, squamous cell carcinomas, etc.